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, 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, 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                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255
 256                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 257                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 258                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 259                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 260
 261                 return $t;
 262         }
 263
 264         /**
 265          * Create a new Title from a namespace index and a DB key.
 266          * It's assumed that $ns and $title are *valid*, for instance when
 267          * they came directly from the database or a special page name.
 268          * For convenience, spaces are converted to underscores so that
 269          * eg user_text fields can be used directly.
 270          *
 271          * @param $ns Int the namespace of the article
 272          * @param $title String the unprefixed database key form
 273          * @param $fragment String the link fragment (after the "#")
 274          * @param $interwiki String the interwiki prefix
 275          * @return Title the new object
 276          */
 277         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 278                 $t = new Title();
 279                 $t->mInterwiki = $interwiki;
 280                 $t->mFragment = $fragment;
 281                 $t->mNamespace = $ns = intval( $ns );
 282                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 283                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 284                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 285                 $t->mTextform = str_replace( '_', ' ', $title );
 286                 return $t;
 287         }
 288
 289         /**
 290          * Create a new Title from a namespace index and a DB key.
 291          * The parameters will be checked for validity, which is a bit slower
 292          * than makeTitle() but safer for user-provided data.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String interwiki prefix
 298          * @return Title the new object, or NULL on an error
 299          */
 300         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 303                 if ( $t->secureAndSplit() ) {
 304                         return $t;
 305                 } else {
 306                         return null;
 307                 }
 308         }
 309
 310         /**
 311          * Create a new Title for the Main Page
 312          *
 313          * @return Title the new object
 314          */
 315         public static function newMainPage() {
 316                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 317                 // Don't give fatal errors if the message is broken
 318                 if ( !$title ) {
 319                         $title = Title::newFromText( 'Main Page' );
 320                 }
 321                 return $title;
 322         }
 323
 324         /**
 325          * Extract a redirect destination from a string and return the
 326          * Title, or null if the text doesn't contain a valid redirect
 327          * This will only return the very next target, useful for
 328          * the redirect table and other checks that don't need full recursion
 329          *
 330          * @param $text String: Text with possible redirect
 331          * @return Title: The corresponding Title
 332          */
 333         public static function newFromRedirect( $text ) {
 334                 return self::newFromRedirectInternal( $text );
 335         }
 336
 337         /**
 338          * Extract a redirect destination from a string and return the
 339          * Title, or null if the text doesn't contain a valid redirect
 340          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 341          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 342          *
 343          * @param $text String Text with possible redirect
 344          * @return Title
 345          */
 346         public static function newFromRedirectRecurse( $text ) {
 347                 $titles = self::newFromRedirectArray( $text );
 348                 return $titles ? array_pop( $titles ) : null;
 349         }
 350
 351         /**
 352          * Extract a redirect destination from a string and return an
 353          * array of Titles, or null if the text doesn't contain a valid redirect
 354          * The last element in the array is the final destination after all redirects
 355          * have been resolved (up to $wgMaxRedirects times)
 356          *
 357          * @param $text String Text with possible redirect
 358          * @return Array of Titles, with the destination last
 359          */
 360         public static function newFromRedirectArray( $text ) {
 361                 global $wgMaxRedirects;
 362                 $title = self::newFromRedirectInternal( $text );
 363                 if ( is_null( $title ) ) {
 364                         return null;
 365                 }
 366                 // recursive check to follow double redirects
 367                 $recurse = $wgMaxRedirects;
 368                 $titles = array( $title );
 369                 while ( --$recurse > 0 ) {
 370                         if ( $title->isRedirect() ) {
 371                                 $article = new Article( $title, 0 );
 372                                 $newtitle = $article->getRedirectTarget();
 373                         } else {
 374                                 break;
 375                         }
 376                         // Redirects to some special pages are not permitted
 377                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 378                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 379                                 $title = $newtitle;
 380                                 $titles[] = $newtitle;
 381                         } else {
 382                                 break;
 383                         }
 384                 }
 385                 return $titles;
 386         }
 387
 388         /**
 389          * Really extract the redirect destination
 390          * Do not call this function directly, use one of the newFromRedirect* functions above
 391          *
 392          * @param $text String Text with possible redirect
 393          * @return Title
 394          */
 395         protected static function newFromRedirectInternal( $text ) {
 396                 global $wgMaxRedirects;
 397                 if ( $wgMaxRedirects < 1 ) {
 398                         //redirects are disabled, so quit early
 399                         return null;
 400                 }
 401                 $redir = MagicWord::get( 'redirect' );
 402                 $text = trim( $text );
 403                 if ( $redir->matchStartAndRemove( $text ) ) {
 404                         // Extract the first link and see if it's usable
 405                         // Ensure that it really does come directly after #REDIRECT
 406                         // Some older redirects included a colon, so don't freak about that!
 407                         $m = array();
 408                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 409                                 // Strip preceding colon used to "escape" categories, etc.
 410                                 // and URL-decode links
 411                                 if ( strpos( $m[1], '%' ) !== false ) {
 412                                         // Match behavior of inline link parsing here;
 413                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 414                                 }
 415                                 $title = Title::newFromText( $m[1] );
 416                                 // If the title is a redirect to bad special pages or is invalid, return null
 417                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 418                                         return null;
 419                                 }
 420                                 return $title;
 421                         }
 422                 }
 423                 return null;
 424         }
 425
 426 # ----------------------------------------------------------------------------
 427 #       Static functions
 428 # ----------------------------------------------------------------------------
 429
 430         /**
 431          * Get the prefixed DB key associated with an ID
 432          *
 433          * @param $id Int the page_id of the article
 434          * @return Title an object representing the article, or NULL if no such article was found
 435          */
 436         public static function nameOf( $id ) {
 437                 $dbr = wfGetDB( DB_SLAVE );
 438
 439                 $s = $dbr->selectRow(
 440                         'page',
 441                         array( 'page_namespace', 'page_title' ),
 442                         array( 'page_id' => $id ),
 443                         __METHOD__
 444                 );
 445                 if ( $s === false ) {
 446                         return null;
 447                 }
 448
 449                 $n = self::makeName( $s->page_namespace, $s->page_title );
 450                 return $n;
 451         }
 452
 453         /**
 454          * Get a regex character class describing the legal characters in a link
 455          *
 456          * @return String the list of characters, not delimited
 457          */
 458         public static function legalChars() {
 459                 global $wgLegalTitleChars;
 460                 return $wgLegalTitleChars;
 461         }
 462
 463         /**
 464          * Get a string representation of a title suitable for
 465          * including in a search index
 466          *
 467          * @param $ns Int a namespace index
 468          * @param $title String text-form main part
 469          * @return String a stripped-down title string ready for the search index
 470          */
 471         public static function indexTitle( $ns, $title ) {
 472                 global $wgContLang;
 473
 474                 $lc = SearchEngine::legalSearchChars() . '&#;';
 475                 $t = $wgContLang->normalizeForSearch( $title );
 476                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 477                 $t = $wgContLang->lc( $t );
 478
 479                 # Handle 's, s'
 480                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 481                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 482
 483                 $t = preg_replace( "/\\s+/", ' ', $t );
 484
 485                 if ( $ns == NS_FILE ) {
 486                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 487                 }
 488                 return trim( $t );
 489         }
 490
 491         /**
 492          * Make a prefixed DB key from a DB key and a namespace index
 493          *
 494          * @param $ns Int numerical representation of the namespace
 495          * @param $title String the DB key form the title
 496          * @param $fragment String The link fragment (after the "#")
 497          * @param $interwiki String The interwiki prefix
 498          * @return String the prefixed form of the title
 499          */
 500         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 501                 global $wgContLang;
 502
 503                 $namespace = $wgContLang->getNsText( $ns );
 504                 $name = $namespace == '' ? $title : "$namespace:$title";
 505                 if ( strval( $interwiki ) != '' ) {
 506                         $name = "$interwiki:$name";
 507                 }
 508                 if ( strval( $fragment ) != '' ) {
 509                         $name .= '#' . $fragment;
 510                 }
 511                 return $name;
 512         }
 513
 514         /**
 515          * Determine whether the object refers to a page within
 516          * this project.
 517          *
 518          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 519          */
 520         public function isLocal() {
 521                 if ( $this->mInterwiki != '' ) {
 522                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 523                 } else {
 524                         return true;
 525                 }
 526         }
 527
 528         /**
 529          * Determine whether the object refers to a page within
 530          * this project and is transcludable.
 531          *
 532          * @return Bool TRUE if this is transcludable
 533          */
 534         public function isTrans() {
 535                 if ( $this->mInterwiki == '' ) {
 536                         return false;
 537                 }
 538
 539                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 540         }
 541
 542         /**
 543          * Returns the DB name of the distant wiki which owns the object.
 544          *
 545          * @return String the DB name
 546          */
 547         public function getTransWikiID() {
 548                 if ( $this->mInterwiki == '' ) {
 549                         return false;
 550                 }
 551
 552                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 553         }
 554
 555         /**
 556          * Escape a text fragment, say from a link, for a URL
 557          *
 558          * @param $fragment string containing a URL or link fragment (after the "#")
 559          * @return String: escaped string
 560          */
 561         static function escapeFragmentForURL( $fragment ) {
 562                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 563                 # fragments appear not to work in IE (at least up to 7) or in at least
 564                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 565                 # to care if they aren't encoded.
 566                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 567         }
 568
 569 # ----------------------------------------------------------------------------
 570 #       Other stuff
 571 # ----------------------------------------------------------------------------
 572
 573         /** Simple accessors */
 574         /**
 575          * Get the text form (spaces not underscores) of the main part
 576          *
 577          * @return String Main part of the title
 578          */
 579         public function getText() { return $this->mTextform; }
 580
 581         /**
 582          * Get the URL-encoded form of the main part
 583          *
 584          * @return String Main part of the title, URL-encoded
 585          */
 586         public function getPartialURL() { return $this->mUrlform; }
 587
 588         /**
 589          * Get the main part with underscores
 590          *
 591          * @return String: Main part of the title, with underscores
 592          */
 593         public function getDBkey() { return $this->mDbkeyform; }
 594
 595         /**
 596          * Get the namespace index, i.e. one of the NS_xxxx constants.
 597          *
 598          * @return Integer: Namespace index
 599          */
 600         public function getNamespace() { return $this->mNamespace; }
 601
 602         /**
 603          * Get the namespace text
 604          *
 605          * @return String: Namespace text
 606          */
 607         public function getNsText() {
 608                 global $wgContLang;
 609
 610                 if ( $this->mInterwiki != '' ) {
 611                         // This probably shouldn't even happen. ohh man, oh yuck.
 612                         // But for interwiki transclusion it sometimes does.
 613                         // Shit. Shit shit shit.
 614                         //
 615                         // Use the canonical namespaces if possible to try to
 616                         // resolve a foreign namespace.
 617                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 618                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 619                         }
 620                 }
 621
 622                 if ( $wgContLang->needsGenderDistinction() &&
 623                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 624                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 625                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 626                 }
 627
 628                 return $wgContLang->getNsText( $this->mNamespace );
 629         }
 630
 631         /**
 632          * Get the DB key with the initial letter case as specified by the user
 633          *
 634          * @return String DB key
 635          */
 636         function getUserCaseDBKey() {
 637                 return $this->mUserCaseDBKey;
 638         }
 639
 640         /**
 641          * Get the namespace text of the subject (rather than talk) page
 642          *
 643          * @return String Namespace text
 644          */
 645         public function getSubjectNsText() {
 646                 global $wgContLang;
 647                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 648         }
 649
 650         /**
 651          * Get the namespace text of the talk page
 652          *
 653          * @return String Namespace text
 654          */
 655         public function getTalkNsText() {
 656                 global $wgContLang;
 657                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 658         }
 659
 660         /**
 661          * Could this title have a corresponding talk page?
 662          *
 663          * @return Bool TRUE or FALSE
 664          */
 665         public function canTalk() {
 666                 return( MWNamespace::canTalk( $this->mNamespace ) );
 667         }
 668
 669         /**
 670          * Get the interwiki prefix (or null string)
 671          *
 672          * @return String Interwiki prefix
 673          */
 674         public function getInterwiki() { return $this->mInterwiki; }
 675
 676         /**
 677          * Get the Title fragment (i.e.\ the bit after the #) in text form
 678          *
 679          * @return String Title fragment
 680          */
 681         public function getFragment() { return $this->mFragment; }
 682
 683         /**
 684          * Get the fragment in URL form, including the "#" character if there is one
 685          * @return String Fragment in URL form
 686          */
 687         public function getFragmentForURL() {
 688                 if ( $this->mFragment == '' ) {
 689                         return '';
 690                 } else {
 691                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 692                 }
 693         }
 694
 695         /**
 696          * Get the default namespace index, for when there is no namespace
 697          *
 698          * @return Int Default namespace index
 699          */
 700         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 701
 702         /**
 703          * Get title for search index
 704          *
 705          * @return String a stripped-down title string ready for the
 706          *  search index
 707          */
 708         public function getIndexTitle() {
 709                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 710         }
 711
 712         /**
 713          * Get the prefixed database key form
 714          *
 715          * @return String the prefixed title, with underscores and
 716          *  any interwiki and namespace prefixes
 717          */
 718         public function getPrefixedDBkey() {
 719                 $s = $this->prefix( $this->mDbkeyform );
 720                 $s = str_replace( ' ', '_', $s );
 721                 return $s;
 722         }
 723
 724         /**
 725          * Get the prefixed title with spaces.
 726          * This is the form usually used for display
 727          *
 728          * @return String the prefixed title, with spaces
 729          */
 730         public function getPrefixedText() {
 731                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 732                         $s = $this->prefix( $this->mTextform );
 733                         $s = str_replace( '_', ' ', $s );
 734                         $this->mPrefixedText = $s;
 735                 }
 736                 return $this->mPrefixedText;
 737         }
 738
 739         /**
 740          * Get the prefixed title with spaces, plus any fragment
 741          * (part beginning with '#')
 742          *
 743          * @return String the prefixed title, with spaces and the fragment, including '#'
 744          */
 745         public function getFullText() {
 746                 $text = $this->getPrefixedText();
 747                 if ( $this->mFragment != '' ) {
 748                         $text .= '#' . $this->mFragment;
 749                 }
 750                 return $text;
 751         }
 752
 753         /**
 754          * Get the base name, i.e. the leftmost parts before the /
 755          *
 756          * @return String Base name
 757          */
 758         public function getBaseText() {
 759                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 760                         return $this->getText();
 761                 }
 762
 763                 $parts = explode( '/', $this->getText() );
 764                 # Don't discard the real title if there's no subpage involved
 765                 if ( count( $parts ) > 1 ) {
 766                         unset( $parts[count( $parts ) - 1] );
 767                 }
 768                 return implode( '/', $parts );
 769         }
 770
 771         /**
 772          * Get the lowest-level subpage name, i.e. the rightmost part after /
 773          *
 774          * @return String Subpage name
 775          */
 776         public function getSubpageText() {
 777                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 778                         return( $this->mTextform );
 779                 }
 780                 $parts = explode( '/', $this->mTextform );
 781                 return( $parts[count( $parts ) - 1] );
 782         }
 783
 784         /**
 785          * Get a URL-encoded form of the subpage text
 786          *
 787          * @return String URL-encoded subpage name
 788          */
 789         public function getSubpageUrlForm() {
 790                 $text = $this->getSubpageText();
 791                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 792                 return( $text );
 793         }
 794
 795         /**
 796          * Get a URL-encoded title (not an actual URL) including interwiki
 797          *
 798          * @return String the URL-encoded form
 799          */
 800         public function getPrefixedURL() {
 801                 $s = $this->prefix( $this->mDbkeyform );
 802                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 803                 return $s;
 804         }
 805
 806         /**
 807          * Get a real URL referring to this title, with interwiki link and
 808          * fragment
 809          *
 810          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 811          *   links. Can be specified as an associative array as well, e.g.,
 812          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 813          * @param $variant String language variant of url (for sr, zh..)
 814          * @return String the URL
 815          */
 816         public function getFullURL( $query = '', $variant = false ) {
 817                 global $wgServer, $wgRequest;
 818
 819                 if ( is_array( $query ) ) {
 820                         $query = wfArrayToCGI( $query );
 821                 }
 822
 823                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 824                 if ( !$interwiki ) {
 825                         $url = $this->getLocalURL( $query, $variant );
 826
 827                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 828                         // Correct fix would be to move the prepending elsewhere.
 829                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 830                                 $url = $wgServer . $url;
 831                         }
 832                 } else {
 833                         $baseUrl = $interwiki->getURL();
 834
 835                         $namespace = wfUrlencode( $this->getNsText() );
 836                         if ( $namespace != '' ) {
 837                                 # Can this actually happen? Interwikis shouldn't be parsed.
 838                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 839                                 $namespace .= ':';
 840                         }
 841                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 842                         $url = wfAppendQuery( $url, $query );
 843                 }
 844
 845                 # Finally, add the fragment.
 846                 $url .= $this->getFragmentForURL();
 847
 848                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 849                 return $url;
 850         }
 851
 852         /**
 853          * Get a URL with no fragment or server name.  If this page is generated
 854          * with action=render, $wgServer is prepended.
 855          *
 856          * @param $query Mixed: an optional query string; if not specified,
 857          *   $wgArticlePath will be used.  Can be specified as an associative array
 858          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 859          *   URL-escaped).
 860          * @param $variant String language variant of url (for sr, zh..)
 861          * @return String the URL
 862          */
 863         public function getLocalURL( $query = '', $variant = false ) {
 864                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 865                 global $wgVariantArticlePath, $wgContLang;
 866
 867                 if ( is_array( $query ) ) {
 868                         $query = wfArrayToCGI( $query );
 869                 }
 870
 871                 if ( $this->isExternal() ) {
 872                         $url = $this->getFullURL();
 873                         if ( $query ) {
 874                                 // This is currently only used for edit section links in the
 875                                 // context of interwiki transclusion. In theory we should
 876                                 // append the query to the end of any existing query string,
 877                                 // but interwiki transclusion is already broken in that case.
 878                                 $url .= "?$query";
 879                         }
 880                 } else {
 881                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 882                         if ( $query == '' ) {
 883                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 884                                         if ( !$wgVariantArticlePath ) {
 885                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 886                                         } else {
 887                                                 $variantArticlePath = $wgVariantArticlePath;
 888                                         }
 889                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 890                                         $url = str_replace( '$1', $dbkey, $url  );
 891                                 } else {
 892                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 893                                 }
 894                         } else {
 895                                 global $wgActionPaths;
 896                                 $url = false;
 897                                 $matches = array();
 898                                 if ( !empty( $wgActionPaths ) &&
 899                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 900                                 {
 901                                         $action = urldecode( $matches[2] );
 902                                         if ( isset( $wgActionPaths[$action] ) ) {
 903                                                 $query = $matches[1];
 904                                                 if ( isset( $matches[4] ) ) {
 905                                                         $query .= $matches[4];
 906                                                 }
 907                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 908                                                 if ( $query != '' ) {
 909                                                         $url = wfAppendQuery( $url, $query );
 910                                                 }
 911                                         }
 912                                 }
 913                                 if ( $url === false ) {
 914                                         if ( $query == '-' ) {
 915                                                 $query = '';
 916                                         }
 917                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 918                                 }
 919                         }
 920
 921                         // FIXME: this causes breakage in various places when we
 922                         // actually expected a local URL and end up with dupe prefixes.
 923                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 924                                 $url = $wgServer . $url;
 925                         }
 926                 }
 927                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 928                 return $url;
 929         }
 930
 931         /**
 932          * Get a URL that's the simplest URL that will be valid to link, locally,
 933          * to the current Title.  It includes the fragment, but does not include
 934          * the server unless action=render is used (or the link is external).  If
 935          * there's a fragment but the prefixed text is empty, we just return a link
 936          * to the fragment.
 937          *
 938          * The result obviously should not be URL-escaped, but does need to be
 939          * HTML-escaped if it's being output in HTML.
 940          *
 941          * @param $query Array of Strings An associative array of key => value pairs for the
 942          *   query string.  Keys and values will be escaped.
 943          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 944          *   for external links.  Default is "false" (same variant as current page,
 945          *   for anonymous users).
 946          * @return String the URL
 947          */
 948         public function getLinkUrl( $query = array(), $variant = false ) {
 949                 wfProfileIn( __METHOD__ );
 950                 if ( $this->isExternal() ) {
 951                         $ret = $this->getFullURL( $query );
 952                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 953                         $ret = $this->getFragmentForURL();
 954                 } else {
 955                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 956                 }
 957                 wfProfileOut( __METHOD__ );
 958                 return $ret;
 959         }
 960
 961         /**
 962          * Get an HTML-escaped version of the URL form, suitable for
 963          * using in a link, without a server name or fragment
 964          *
 965          * @param $query String an optional query string
 966          * @return String the URL
 967          */
 968         public function escapeLocalURL( $query = '' ) {
 969                 return htmlspecialchars( $this->getLocalURL( $query ) );
 970         }
 971
 972         /**
 973          * Get an HTML-escaped version of the URL form, suitable for
 974          * using in a link, including the server name and fragment
 975          *
 976          * @param $query String an optional query string
 977          * @return String the URL
 978          */
 979         public function escapeFullURL( $query = '' ) {
 980                 return htmlspecialchars( $this->getFullURL( $query ) );
 981         }
 982
 983         /**
 984          * Get the URL form for an internal link.
 985          * - Used in various Squid-related code, in case we have a different
 986          * internal hostname for the server from the exposed one.
 987          *
 988          * @param $query String an optional query string
 989          * @param $variant String language variant of url (for sr, zh..)
 990          * @return String the URL
 991          */
 992         public function getInternalURL( $query = '', $variant = false ) {
 993                 global $wgInternalServer;
 994                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 995                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 996                 return $url;
 997         }
 998
 999         /**
1000          * Get the edit URL for this Title
1001          *
1002          * @return String the URL, or a null string if this is an
1003          *  interwiki link
1004          */
1005         public function getEditURL() {
1006                 if ( $this->mInterwiki != '' ) {
1007                         return '';
1008                 }
1009                 $s = $this->getLocalURL( 'action=edit' );
1010
1011                 return $s;
1012         }
1013
1014         /**
1015          * Get the HTML-escaped displayable text form.
1016          * Used for the title field in <a> tags.
1017          *
1018          * @return String the text, including any prefixes
1019          */
1020         public function getEscapedText() {
1021                 return htmlspecialchars( $this->getPrefixedText() );
1022         }
1023
1024         /**
1025          * Is this Title interwiki?
1026          *
1027          * @return Bool
1028          */
1029         public function isExternal() {
1030                 return ( $this->mInterwiki != '' );
1031         }
1032
1033         /**
1034          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1035          *
1036          * @param $action String Action to check (default: edit)
1037          * @return Bool
1038          */
1039         public function isSemiProtected( $action = 'edit' ) {
1040                 if ( $this->exists() ) {
1041                         $restrictions = $this->getRestrictions( $action );
1042                         if ( count( $restrictions ) > 0 ) {
1043                                 foreach ( $restrictions as $restriction ) {
1044                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1045                                                 return false;
1046                                         }
1047                                 }
1048                         } else {
1049                                 # Not protected
1050                                 return false;
1051                         }
1052                         return true;
1053                 } else {
1054                         # If it doesn't exist, it can't be protected
1055                         return false;
1056                 }
1057         }
1058
1059         /**
1060          * Does the title correspond to a protected article?
1061          *
1062          * @param $action String the action the page is protected from,
1063          * by default checks all actions.
1064          * @return Bool
1065          */
1066         public function isProtected( $action = '' ) {
1067                 global $wgRestrictionLevels;
1068
1069                 $restrictionTypes = $this->getRestrictionTypes();
1070
1071                 # Special pages have inherent protection
1072                 if( $this->getNamespace() == NS_SPECIAL ) {
1073                         return true;
1074                 }
1075
1076                 # Check regular protection levels
1077                 foreach ( $restrictionTypes as $type ) {
1078                         if ( $action == $type || $action == '' ) {
1079                                 $r = $this->getRestrictions( $type );
1080                                 foreach ( $wgRestrictionLevels as $level ) {
1081                                         if ( in_array( $level, $r ) && $level != '' ) {
1082                                                 return true;
1083                                         }
1084                                 }
1085                         }
1086                 }
1087
1088                 return false;
1089         }
1090
1091         /**
1092          * Is this a conversion table for the LanguageConverter?
1093          *
1094          * @return Bool
1095          */
1096         public function isConversionTable() {
1097                 if(
1098                         $this->getNamespace() == NS_MEDIAWIKI &&
1099                         strpos( $this->getText(), 'Conversiontable' ) !== false
1100                 )
1101                 {
1102                         return true;
1103                 }
1104
1105                 return false;
1106         }
1107
1108         /**
1109          * Is $wgUser watching this page?
1110          *
1111          * @return Bool
1112          */
1113         public function userIsWatching() {
1114                 global $wgUser;
1115
1116                 if ( is_null( $this->mWatched ) ) {
1117                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1118                                 $this->mWatched = false;
1119                         } else {
1120                                 $this->mWatched = $wgUser->isWatched( $this );
1121                         }
1122                 }
1123                 return $this->mWatched;
1124         }
1125
1126         /**
1127          * Can $wgUser perform $action on this page?
1128          * This skips potentially expensive cascading permission checks
1129          * as well as avoids expensive error formatting
1130          *
1131          * Suitable for use for nonessential UI controls in common cases, but
1132          * _not_ for functional access control.
1133          *
1134          * May provide false positives, but should never provide a false negative.
1135          *
1136          * @param $action String action that permission needs to be checked for
1137          * @return Bool
1138          */
1139         public function quickUserCan( $action ) {
1140                 return $this->userCan( $action, false );
1141         }
1142
1143         /**
1144          * Determines if $user is unable to edit this page because it has been protected
1145          * by $wgNamespaceProtection.
1146          *
1147          * @param $user User object, $wgUser will be used if not passed
1148          * @return Bool
1149          */
1150         public function isNamespaceProtected( User $user = null ) {
1151                 global $wgNamespaceProtection;
1152
1153                 if ( $user === null ) {
1154                         global $wgUser;
1155                         $user = $wgUser;
1156                 }
1157
1158                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1159                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1160                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1161                                         return true;
1162                                 }
1163                         }
1164                 }
1165                 return false;
1166         }
1167
1168         /**
1169          * Can $wgUser perform $action on this page?
1170          *
1171          * @param $action String action that permission needs to be checked for
1172          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1173          * @return Bool
1174          */
1175         public function userCan( $action, $doExpensiveQueries = true ) {
1176                 global $wgUser;
1177                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1178         }
1179
1180         /**
1181          * Can $user perform $action on this page?
1182          *
1183          * FIXME: This *does not* check throttles (User::pingLimiter()).
1184          *
1185          * @param $action String action that permission needs to be checked for
1186          * @param $user User to check
1187          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1188          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1189          * @return Array of arguments to wfMsg to explain permissions problems.
1190          */
1191         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1192                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1193
1194                 // Remove the errors being ignored.
1195                 foreach ( $errors as $index => $error ) {
1196                         $error_key = is_array( $error ) ? $error[0] : $error;
1197
1198                         if ( in_array( $error_key, $ignoreErrors ) ) {
1199                                 unset( $errors[$index] );
1200                         }
1201                 }
1202
1203                 return $errors;
1204         }
1205
1206         /**
1207          * Permissions checks that fail most often, and which are easiest to test.
1208          *
1209          * @param $action String the action to check
1210          * @param $user User user to check
1211          * @param $errors Array list of current errors
1212          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1213          * @param $short Boolean short circuit on first error
1214          *
1215          * @return Array list of errors
1216          */
1217         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1218                 if ( $action == 'create' ) {
1219                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1220                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1221                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1222                         }
1223                 } elseif ( $action == 'move' ) {
1224                         if ( !$user->isAllowed( 'move-rootuserpages' )
1225                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1226                                 // Show user page-specific message only if the user can move other pages
1227                                 $errors[] = array( 'cant-move-user-page' );
1228                         }
1229
1230                         // Check if user is allowed to move files if it's a file
1231                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1232                                 $errors[] = array( 'movenotallowedfile' );
1233                         }
1234
1235                         if ( !$user->isAllowed( 'move' ) ) {
1236                                 // User can't move anything
1237                                 global $wgGroupPermissions;
1238                                 $userCanMove = false;
1239                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1240                                         $userCanMove = $wgGroupPermissions['user']['move'];
1241                                 }
1242                                 $autoconfirmedCanMove = false;
1243                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1244                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1245                                 }
1246                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1247                                         // custom message if logged-in users without any special rights can move
1248                                         $errors[] = array( 'movenologintext' );
1249                                 } else {
1250                                         $errors[] = array( 'movenotallowed' );
1251                                 }
1252                         }
1253                 } elseif ( $action == 'move-target' ) {
1254                         if ( !$user->isAllowed( 'move' ) ) {
1255                                 // User can't move anything
1256                                 $errors[] = array( 'movenotallowed' );
1257                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1258                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1259                                 // Show user page-specific message only if the user can move other pages
1260                                 $errors[] = array( 'cant-move-to-user-page' );
1261                         }
1262                 } elseif ( !$user->isAllowed( $action ) ) {
1263                         // We avoid expensive display logic for quickUserCan's and such
1264                         $groups = false;
1265                         if ( !$short ) {
1266                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1267                                         User::getGroupsWithPermission( $action ) );
1268                         }
1269
1270                         if ( $groups ) {
1271                                 global $wgLang;
1272                                 $return = array(
1273                                         'badaccess-groups',
1274                                         $wgLang->commaList( $groups ),
1275                                         count( $groups )
1276                                 );
1277                         } else {
1278                                 $return = array( 'badaccess-group0' );
1279                         }
1280                         $errors[] = $return;
1281                 }
1282
1283                 return $errors;
1284         }
1285
1286         /**
1287          * Add the resulting error code to the errors array
1288          *
1289          * @param $errors Array list of current errors
1290          * @param $result Mixed result of errors
1291          *
1292          * @return Array list of errors
1293          */
1294         private function resultToError( $errors, $result ) {
1295                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1296                         // A single array representing an error
1297                         $errors[] = $result;
1298                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1299                         // A nested array representing multiple errors
1300                         $errors = array_merge( $errors, $result );
1301                 } else if ( $result !== '' && is_string( $result ) ) {
1302                         // A string representing a message-id
1303                         $errors[] = array( $result );
1304                 } else if ( $result === false ) {
1305                         // a generic "We don't want them to do that"
1306                         $errors[] = array( 'badaccess-group0' );
1307                 }
1308                 return $errors;
1309         }
1310
1311         /**
1312          * Check various permission hooks
1313          *
1314          * @param $action String the action to check
1315          * @param $user User user to check
1316          * @param $errors Array list of current errors
1317          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1318          * @param $short Boolean short circuit on first error
1319          *
1320          * @return Array list of errors
1321          */
1322         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1323                 // Use getUserPermissionsErrors instead
1324                 $result = '';
1325                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1326                         return $result ? array() : array( array( 'badaccess-group0' ) );
1327                 }
1328                 // Check getUserPermissionsErrors hook
1329                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1330                         $errors = $this->resultToError( $errors, $result );
1331                 }
1332                 // Check getUserPermissionsErrorsExpensive hook
1333                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1334                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1335                         $errors = $this->resultToError( $errors, $result );
1336                 }
1337
1338                 return $errors;
1339         }
1340
1341         /**
1342          * Check permissions on special pages & namespaces
1343          *
1344          * @param $action String the action to check
1345          * @param $user User user to check
1346          * @param $errors Array list of current errors
1347          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1348          * @param $short Boolean short circuit on first error
1349          *
1350          * @return Array list of errors
1351          */
1352         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1353                 # Only 'createaccount' and 'execute' can be performed on
1354                 # special pages, which don't actually exist in the DB.
1355                 $specialOKActions = array( 'createaccount', 'execute' );
1356                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1357                         $errors[] = array( 'ns-specialprotected' );
1358                 }
1359
1360                 # Check $wgNamespaceProtection for restricted namespaces
1361                 if ( $this->isNamespaceProtected( $user ) ) {
1362                         $ns = $this->mNamespace == NS_MAIN ?
1363                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1364                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1365                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1366                 }
1367
1368                 return $errors;
1369         }
1370
1371         /**
1372          * Check CSS/JS sub-page permissions
1373          *
1374          * @param $action String the action to check
1375          * @param $user User user to check
1376          * @param $errors Array list of current errors
1377          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1378          * @param $short Boolean short circuit on first error
1379          *
1380          * @return Array list of errors
1381          */
1382         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1383                 # Protect css/js subpages of user pages
1384                 # XXX: this might be better using restrictions
1385                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1386                 #      and $this->userCanEditJsSubpage() from working
1387                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1388                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1389                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1390                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1391                                 $errors[] = array( 'customcssjsprotected' );
1392                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1393                                 $errors[] = array( 'customcssjsprotected' );
1394                         }
1395                 }
1396
1397                 return $errors;
1398         }
1399
1400         /**
1401          * Check against page_restrictions table requirements on this
1402          * page. The user must possess all required rights for this
1403          * action.
1404          *
1405          * @param $action String the action to check
1406          * @param $user User user to check
1407          * @param $errors Array list of current errors
1408          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1409          * @param $short Boolean short circuit on first error
1410          *
1411          * @return Array list of errors
1412          */
1413         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1414                 foreach ( $this->getRestrictions( $action ) as $right ) {
1415                         // Backwards compatibility, rewrite sysop -> protect
1416                         if ( $right == 'sysop' ) {
1417                                 $right = 'protect';
1418                         }
1419                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1420                                 // Users with 'editprotected' permission can edit protected pages
1421                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1422                                         // Users with 'editprotected' permission cannot edit protected pages
1423                                         // with cascading option turned on.
1424                                         if ( $this->mCascadeRestriction ) {
1425                                                 $errors[] = array( 'protectedpagetext', $right );
1426                                         }
1427                                 } else {
1428                                         $errors[] = array( 'protectedpagetext', $right );
1429                                 }
1430                         }
1431                 }
1432
1433                 return $errors;
1434         }
1435
1436         /**
1437          * Check restrictions on cascading pages.
1438          *
1439          * @param $action String the action to check
1440          * @param $user User to check
1441          * @param $errors Array list of current errors
1442          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1443          * @param $short Boolean short circuit on first error
1444          *
1445          * @return Array list of errors
1446          */
1447         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1448                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1449                         # We /could/ use the protection level on the source page, but it's
1450                         # fairly ugly as we have to establish a precedence hierarchy for pages
1451                         # included by multiple cascade-protected pages. So just restrict
1452                         # it to people with 'protect' permission, as they could remove the
1453                         # protection anyway.
1454                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1455                         # Cascading protection depends on more than this page...
1456                         # Several cascading protected pages may include this page...
1457                         # Check each cascading level
1458                         # This is only for protection restrictions, not for all actions
1459                         if ( isset( $restrictions[$action] ) ) {
1460                                 foreach ( $restrictions[$action] as $right ) {
1461                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1462                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1463                                                 $pages = '';
1464                                                 foreach ( $cascadingSources as $page )
1465                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1466                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1467                                         }
1468                                 }
1469                         }
1470                 }
1471
1472                 return $errors;
1473         }
1474
1475         /**
1476          * Check action permissions not already checked in checkQuickPermissions
1477          *
1478          * @param $action String the action to check
1479          * @param $user User to check
1480          * @param $errors Array list of current errors
1481          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1482          * @param $short Boolean short circuit on first error
1483          *
1484          * @return Array list of errors
1485          */
1486         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1487                 if ( $action == 'protect' ) {
1488                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1489                                 // If they can't edit, they shouldn't protect.
1490                                 $errors[] = array( 'protect-cantedit' );
1491                         }
1492                 } elseif ( $action == 'create' ) {
1493                         $title_protection = $this->getTitleProtection();
1494                         if( $title_protection ) {
1495                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1496                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1497                                 }
1498                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1499                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1500                                 }
1501                         }
1502                 } elseif ( $action == 'move' ) {
1503                         // Check for immobile pages
1504                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1505                                 // Specific message for this case
1506                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1507                         } elseif ( !$this->isMovable() ) {
1508                                 // Less specific message for rarer cases
1509                                 $errors[] = array( 'immobile-page' );
1510                         }
1511                 } elseif ( $action == 'move-target' ) {
1512                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1513                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1514                         } elseif ( !$this->isMovable() ) {
1515                                 $errors[] = array( 'immobile-target-page' );
1516                         }
1517                 }
1518                 return $errors;
1519         }
1520
1521         /**
1522          * Check that the user isn't blocked from editting.
1523          *
1524          * @param $action String the action to check
1525          * @param $user User to check
1526          * @param $errors Array list of current errors
1527          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1528          * @param $short Boolean short circuit on first error
1529          *
1530          * @return Array list of errors
1531          */
1532         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1533                 if( $short && count( $errors ) > 0 ) {
1534                         return $errors;
1535                 }
1536
1537                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1538
1539                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1540                         $errors[] = array( 'confirmedittext' );
1541                 }
1542
1543                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1544                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1545                         $block = $user->mBlock;
1546
1547                         // This is from OutputPage::blockedPage
1548                         // Copied at r23888 by werdna
1549
1550                         $id = $user->blockedBy();
1551                         $reason = $user->blockedFor();
1552                         if ( $reason == '' ) {
1553                                 $reason = wfMsg( 'blockednoreason' );
1554                         }
1555                         $ip = wfGetIP();
1556
1557                         if ( is_numeric( $id ) ) {
1558                                 $name = User::whoIs( $id );
1559                         } else {
1560                                 $name = $id;
1561                         }
1562
1563                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1564                         $blockid = $block->mId;
1565                         $blockExpiry = $user->mBlock->mExpiry;
1566                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1567                         if ( $blockExpiry == 'infinity' ) {
1568                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1569                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1570
1571                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1572                                         if ( !strpos( $option, ':' ) )
1573                                                 continue;
1574
1575                                         list( $show, $value ) = explode( ':', $option );
1576
1577                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1578                                                 $blockExpiry = $show;
1579                                                 break;
1580                                         }
1581                                 }
1582                         } else {
1583                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1584                         }
1585
1586                         $intended = $user->mBlock->mAddress;
1587
1588                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1589                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1590                 }
1591
1592                 return $errors;
1593         }
1594
1595         /**
1596          * Can $user perform $action on this page? This is an internal function,
1597          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1598          * checks on wfReadOnly() and blocks)
1599          *
1600          * @param $action String action that permission needs to be checked for
1601          * @param $user User to check
1602          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1603          * @param $short Bool Set this to true to stop after the first permission error.
1604          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1605          */
1606         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1607                 wfProfileIn( __METHOD__ );
1608
1609                 $errors = array();
1610                 $checks = array(
1611                         'checkQuickPermissions',
1612                         'checkPermissionHooks',
1613                         'checkSpecialsAndNSPermissions',
1614                         'checkCSSandJSPermissions',
1615                         'checkPageRestrictions',
1616                         'checkCascadingSourcesRestrictions',
1617                         'checkActionPermissions',
1618                         'checkUserBlock'
1619                 );
1620
1621                 while( count( $checks ) > 0 &&
1622                            !( $short && count( $errors ) > 0 ) ) {
1623                         $method = array_shift( $checks );
1624                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1625                 }
1626
1627                 wfProfileOut( __METHOD__ );
1628                 return $errors;
1629         }
1630
1631         /**
1632          * Is this title subject to title protection?
1633          * Title protection is the one applied against creation of such title.
1634          *
1635          * @return Mixed An associative array representing any existent title
1636          *   protection, or false if there's none.
1637          */
1638         private function getTitleProtection() {
1639                 // Can't protect pages in special namespaces
1640                 if ( $this->getNamespace() < 0 ) {
1641                         return false;
1642                 }
1643
1644                 // Can't protect pages that exist.
1645                 if ( $this->exists() ) {
1646                         return false;
1647                 }
1648
1649                 if ( !isset( $this->mTitleProtection ) ) {
1650                         $dbr = wfGetDB( DB_SLAVE );
1651                         $res = $dbr->select( 'protected_titles', '*',
1652                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1653                                 __METHOD__ );
1654
1655                         // fetchRow returns false if there are no rows.
1656                         $this->mTitleProtection = $dbr->fetchRow( $res );
1657                 }
1658                 return $this->mTitleProtection;
1659         }
1660
1661         /**
1662          * Update the title protection status
1663          *
1664          * @param $create_perm String Permission required for creation
1665          * @param $reason String Reason for protection
1666          * @param $expiry String Expiry timestamp
1667          * @return boolean true
1668          */
1669         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1670                 global $wgUser, $wgContLang;
1671
1672                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1673                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1674                         // No change
1675                         return true;
1676                 }
1677
1678                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1679
1680                 $dbw = wfGetDB( DB_MASTER );
1681
1682                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1683
1684                 $expiry_description = '';
1685                 if ( $encodedExpiry != 'infinity' ) {
1686                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1687                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1688                 } else {
1689                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1690                 }
1691
1692                 # Update protection table
1693                 if ( $create_perm != '' ) {
1694                         $this->mTitleProtection = array(
1695                                         'pt_namespace' => $namespace,
1696                                         'pt_title' => $title,
1697                                         'pt_create_perm' => $create_perm,
1698                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1699                                         'pt_expiry' => $encodedExpiry,
1700                                         'pt_user' => $wgUser->getId(),
1701                                         'pt_reason' => $reason,
1702                                 );
1703                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1704                                 $this->mTitleProtection, __METHOD__     );
1705                 } else {
1706                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1707                                 'pt_title' => $title ), __METHOD__ );
1708                         $this->mTitleProtection = false;
1709                 }
1710
1711                 # Update the protection log
1712                 if ( $dbw->affectedRows() ) {
1713                         $log = new LogPage( 'protect' );
1714
1715                         if ( $create_perm ) {
1716                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1717                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1718                         } else {
1719                                 $log->addEntry( 'unprotect', $this, $reason );
1720                         }
1721                 }
1722
1723                 return true;
1724         }
1725
1726         /**
1727          * Remove any title protection due to page existing
1728          */
1729         public function deleteTitleProtection() {
1730                 $dbw = wfGetDB( DB_MASTER );
1731
1732                 $dbw->delete(
1733                         'protected_titles',
1734                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1735                         __METHOD__
1736                 );
1737                 $this->mTitleProtection = false;
1738         }
1739
1740         /**
1741          * Would anybody with sufficient privileges be able to move this page?
1742          * Some pages just aren't movable.
1743          *
1744          * @return Bool TRUE or FALSE
1745          */
1746         public function isMovable() {
1747                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1748         }
1749
1750         /**
1751          * Can $wgUser read this page?
1752          *
1753          * @return Bool
1754          * @todo fold these checks into userCan()
1755          */
1756         public function userCanRead() {
1757                 global $wgUser, $wgGroupPermissions;
1758
1759                 static $useShortcut = null;
1760
1761                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1762                 if ( is_null( $useShortcut ) ) {
1763                         global $wgRevokePermissions;
1764                         $useShortcut = true;
1765                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1766                                 # Not a public wiki, so no shortcut
1767                                 $useShortcut = false;
1768                         } elseif ( !empty( $wgRevokePermissions ) ) {
1769                                 /*
1770                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1771                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1772                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1773                                  * reading is allowed.
1774                                  */
1775                                 foreach ( $wgRevokePermissions as $perms ) {
1776                                         if ( !empty( $perms['read'] ) ) {
1777                                                 # We might be removing the read right from the user, so no shortcut
1778                                                 $useShortcut = false;
1779                                                 break;
1780                                         }
1781                                 }
1782                         }
1783                 }
1784
1785                 $result = null;
1786                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1787                 if ( $result !== null ) {
1788                         return $result;
1789                 }
1790
1791                 # Shortcut for public wikis, allows skipping quite a bit of code
1792                 if ( $useShortcut ) {
1793                         return true;
1794                 }
1795
1796                 if ( $wgUser->isAllowed( 'read' ) ) {
1797                         return true;
1798                 } else {
1799                         global $wgWhitelistRead;
1800
1801                         # Always grant access to the login page.
1802                         # Even anons need to be able to log in.
1803                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1804                                 return true;
1805                         }
1806
1807                         # Bail out if there isn't whitelist
1808                         if ( !is_array( $wgWhitelistRead ) ) {
1809                                 return false;
1810                         }
1811
1812                         # Check for explicit whitelisting
1813                         $name = $this->getPrefixedText();
1814                         $dbName = $this->getPrefixedDBKey();
1815                         // Check with and without underscores
1816                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1817                                 return true;
1818
1819                         # Old settings might have the title prefixed with
1820                         # a colon for main-namespace pages
1821                         if ( $this->getNamespace() == NS_MAIN ) {
1822                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1823                                         return true;
1824                                 }
1825                         }
1826
1827                         # If it's a special page, ditch the subpage bit and check again
1828                         if ( $this->getNamespace() == NS_SPECIAL ) {
1829                                 $name = $this->getDBkey();
1830                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1831                                 if ( $name === false ) {
1832                                         # Invalid special page, but we show standard login required message
1833                                         return false;
1834                                 }
1835
1836                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1837                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1838                                         return true;
1839                                 }
1840                         }
1841
1842                 }
1843                 return false;
1844         }
1845
1846         /**
1847          * Is this the mainpage?
1848          * @note Title::newFromText seams to be sufficiently optimized by the title
1849          * cache that we don't need to over-optimize by doing direct comparisons and
1850          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1851          * ends up reporting something differently than $title->isMainPage();
1852          *
1853          * @return Bool
1854          */
1855         public function isMainPage() {
1856                 return $this->equals( Title::newMainPage() );
1857         }
1858
1859         /**
1860          * Is this a talk page of some sort?
1861          *
1862          * @return Bool
1863          */
1864         public function isTalkPage() {
1865                 return MWNamespace::isTalk( $this->getNamespace() );
1866         }
1867
1868         /**
1869          * Is this a subpage?
1870          *
1871          * @return Bool
1872          */
1873         public function isSubpage() {
1874                 return MWNamespace::hasSubpages( $this->mNamespace )
1875                         ? strpos( $this->getText(), '/' ) !== false
1876                         : false;
1877         }
1878
1879         /**
1880          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1881          *
1882          * @return Bool
1883          */
1884         public function hasSubpages() {
1885                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1886                         # Duh
1887                         return false;
1888                 }
1889
1890                 # We dynamically add a member variable for the purpose of this method
1891                 # alone to cache the result.  There's no point in having it hanging
1892                 # around uninitialized in every Title object; therefore we only add it
1893                 # if needed and don't declare it statically.
1894                 if ( isset( $this->mHasSubpages ) ) {
1895                         return $this->mHasSubpages;
1896                 }
1897
1898                 $subpages = $this->getSubpages( 1 );
1899                 if ( $subpages instanceof TitleArray ) {
1900                         return $this->mHasSubpages = (bool)$subpages->count();
1901                 }
1902                 return $this->mHasSubpages = false;
1903         }
1904
1905         /**
1906          * Get all subpages of this page.
1907          *
1908          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1909          * @return mixed TitleArray, or empty array if this page's namespace
1910          *  doesn't allow subpages
1911          */
1912         public function getSubpages( $limit = -1 ) {
1913                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1914                         return array();
1915                 }
1916
1917                 $dbr = wfGetDB( DB_SLAVE );
1918                 $conds['page_namespace'] = $this->getNamespace();
1919                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1920                 $options = array();
1921                 if ( $limit > -1 ) {
1922                         $options['LIMIT'] = $limit;
1923                 }
1924                 return $this->mSubpages = TitleArray::newFromResult(
1925                         $dbr->select( 'page',
1926                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1927                                 $conds,
1928                                 __METHOD__,
1929                                 $options
1930                         )
1931                 );
1932         }
1933
1934         /**
1935          * Could this page contain custom CSS or JavaScript, based
1936          * on the title?
1937          *
1938          * @return Bool
1939          */
1940         public function isCssOrJsPage() {
1941                 return $this->mNamespace == NS_MEDIAWIKI
1942                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1943         }
1944
1945         /**
1946          * Is this a .css or .js subpage of a user page?
1947          * @return Bool
1948          */
1949         public function isCssJsSubpage() {
1950                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1951         }
1952
1953         /**
1954          * Is this a *valid* .css or .js subpage of a user page?
1955          *
1956          * @return Bool
1957          * @deprecated @since 1.17
1958          */
1959         public function isValidCssJsSubpage() {
1960                 return $this->isCssJsSubpage();
1961         }
1962
1963         /**
1964          * Trim down a .css or .js subpage title to get the corresponding skin name
1965          *
1966          * @return string containing skin name from .css or .js subpage title
1967          */
1968         public function getSkinFromCssJsSubpage() {
1969                 $subpage = explode( '/', $this->mTextform );
1970                 $subpage = $subpage[ count( $subpage ) - 1 ];
1971                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1972         }
1973
1974         /**
1975          * Is this a .css subpage of a user page?
1976          *
1977          * @return Bool
1978          */
1979         public function isCssSubpage() {
1980                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1981         }
1982
1983         /**
1984          * Is this a .js subpage of a user page?
1985          *
1986          * @return Bool
1987          */
1988         public function isJsSubpage() {
1989                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1990         }
1991
1992         /**
1993          * Protect css subpages of user pages: can $wgUser edit
1994          * this page?
1995          *
1996          * @return Bool
1997          * @todo XXX: this might be better using restrictions
1998          */
1999         public function userCanEditCssSubpage() {
2000                 global $wgUser;
2001                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
2002                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2003         }
2004
2005         /**
2006          * Protect js subpages of user pages: can $wgUser edit
2007          * this page?
2008          *
2009          * @return Bool
2010          * @todo XXX: this might be better using restrictions
2011          */
2012         public function userCanEditJsSubpage() {
2013                 global $wgUser;
2014                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2015                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2016         }
2017
2018         /**
2019          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2020          *
2021          * @return Bool If the page is subject to cascading restrictions.
2022          */
2023         public function isCascadeProtected() {
2024                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2025                 return ( $sources > 0 );
2026         }
2027
2028         /**
2029          * Cascading protection: Get the source of any cascading restrictions on this page.
2030          *
2031          * @param $getPages Bool Whether or not to retrieve the actual pages
2032          *        that the restrictions have come from.
2033          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2034          *     have come, false for none, or true if such restrictions exist, but $getPages
2035          *     was not set.  The restriction array is an array of each type, each of which
2036          *     contains a array of unique groups.
2037          */
2038         public function getCascadeProtectionSources( $getPages = true ) {
2039                 $pagerestrictions = array();
2040
2041                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2042                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2043                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2044                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2045                 }
2046
2047                 wfProfileIn( __METHOD__ );
2048
2049                 $dbr = wfGetDB( DB_SLAVE );
2050
2051                 if ( $this->getNamespace() == NS_FILE ) {
2052                         $tables = array( 'imagelinks', 'page_restrictions' );
2053                         $where_clauses = array(
2054                                 'il_to' => $this->getDBkey(),
2055                                 'il_from=pr_page',
2056                                 'pr_cascade' => 1
2057                         );
2058                 } else {
2059                         $tables = array( 'templatelinks', 'page_restrictions' );
2060                         $where_clauses = array(
2061                                 'tl_namespace' => $this->getNamespace(),
2062                                 'tl_title' => $this->getDBkey(),
2063                                 'tl_from=pr_page',
2064                                 'pr_cascade' => 1
2065                         );
2066                 }
2067
2068                 if ( $getPages ) {
2069                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2070                                                    'pr_expiry', 'pr_type', 'pr_level' );
2071                         $where_clauses[] = 'page_id=pr_page';
2072                         $tables[] = 'page';
2073                 } else {
2074                         $cols = array( 'pr_expiry' );
2075                 }
2076
2077                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2078
2079                 $sources = $getPages ? array() : false;
2080                 $now = wfTimestampNow();
2081                 $purgeExpired = false;
2082
2083                 foreach ( $res as $row ) {
2084                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2085                         if ( $expiry > $now ) {
2086                                 if ( $getPages ) {
2087                                         $page_id = $row->pr_page;
2088                                         $page_ns = $row->page_namespace;
2089                                         $page_title = $row->page_title;
2090                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2091                                         # Add groups needed for each restriction type if its not already there
2092                                         # Make sure this restriction type still exists
2093
2094                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2095                                                 $pagerestrictions[$row->pr_type] = array();
2096                                         }
2097
2098                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2099                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2100                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2101                                         }
2102                                 } else {
2103                                         $sources = true;
2104                                 }
2105                         } else {
2106                                 // Trigger lazy purge of expired restrictions from the db
2107                                 $purgeExpired = true;
2108                         }
2109                 }
2110                 if ( $purgeExpired ) {
2111                         Title::purgeExpiredRestrictions();
2112                 }
2113
2114                 if ( $getPages ) {
2115                         $this->mCascadeSources = $sources;
2116                         $this->mCascadingRestrictions = $pagerestrictions;
2117                 } else {
2118                         $this->mHasCascadingRestrictions = $sources;
2119                 }
2120
2121                 wfProfileOut( __METHOD__ );
2122                 return array( $sources, $pagerestrictions );
2123         }
2124
2125         /**
2126          * Returns cascading restrictions for the current article
2127          *
2128          * @return Boolean
2129          */
2130         function areRestrictionsCascading() {
2131                 if ( !$this->mRestrictionsLoaded ) {
2132                         $this->loadRestrictions();
2133                 }
2134
2135                 return $this->mCascadeRestriction;
2136         }
2137
2138         /**
2139          * Loads a string into mRestrictions array
2140          *
2141          * @param $res Resource restrictions as an SQL result.
2142          * @param $oldFashionedRestrictions String comma-separated list of page
2143          *        restrictions from page table (pre 1.10)
2144          */
2145         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2146                 $rows = array();
2147
2148                 foreach ( $res as $row ) {
2149                         $rows[] = $row;
2150                 }
2151
2152                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2153         }
2154
2155         /**
2156          * Compiles list of active page restrictions from both page table (pre 1.10)
2157          * and page_restrictions table for this existing page.
2158          * Public for usage by LiquidThreads.
2159          *
2160          * @param $rows array of db result objects
2161          * @param $oldFashionedRestrictions string comma-separated list of page
2162          *        restrictions from page table (pre 1.10)
2163          */
2164         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2165                 $dbr = wfGetDB( DB_SLAVE );
2166
2167                 $restrictionTypes = $this->getRestrictionTypes();
2168
2169                 foreach ( $restrictionTypes as $type ) {
2170                         $this->mRestrictions[$type] = array();
2171                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2172                 }
2173
2174                 $this->mCascadeRestriction = false;
2175
2176                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2177
2178                 if ( $oldFashionedRestrictions === null ) {
2179                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2180                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2181                 }
2182
2183                 if ( $oldFashionedRestrictions != '' ) {
2184
2185                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2186                                 $temp = explode( '=', trim( $restrict ) );
2187                                 if ( count( $temp ) == 1 ) {
2188                                         // old old format should be treated as edit/move restriction
2189                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2190                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2191                                 } else {
2192                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2193                                 }
2194                         }
2195
2196                         $this->mOldRestrictions = true;
2197
2198                 }
2199
2200                 if ( count( $rows ) ) {
2201                         # Current system - load second to make them override.
2202                         $now = wfTimestampNow();
2203                         $purgeExpired = false;
2204
2205                         # Cycle through all the restrictions.
2206                         foreach ( $rows as $row ) {
2207
2208                                 // Don't take care of restrictions types that aren't allowed
2209                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2210                                         continue;
2211
2212                                 // This code should be refactored, now that it's being used more generally,
2213                                 // But I don't really see any harm in leaving it in Block for now -werdna
2214                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2215
2216                                 // Only apply the restrictions if they haven't expired!
2217                                 if ( !$expiry || $expiry > $now ) {
2218                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2219                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2220
2221                                         $this->mCascadeRestriction |= $row->pr_cascade;
2222                                 } else {
2223                                         // Trigger a lazy purge of expired restrictions
2224                                         $purgeExpired = true;
2225                                 }
2226                         }
2227
2228                         if ( $purgeExpired ) {
2229                                 Title::purgeExpiredRestrictions();
2230                         }
2231                 }
2232
2233                 $this->mRestrictionsLoaded = true;
2234         }
2235
2236         /**
2237          * Load restrictions from the page_restrictions table
2238          *
2239          * @param $oldFashionedRestrictions String comma-separated list of page
2240          *        restrictions from page table (pre 1.10)
2241          */
2242         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2243                 if ( !$this->mRestrictionsLoaded ) {
2244                         if ( $this->exists() ) {
2245                                 $dbr = wfGetDB( DB_SLAVE );
2246
2247                                 $res = $dbr->select( 'page_restrictions', '*',
2248                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2249
2250                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2251                         } else {
2252                                 $title_protection = $this->getTitleProtection();
2253
2254                                 if ( $title_protection ) {
2255                                         $now = wfTimestampNow();
2256                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2257
2258                                         if ( !$expiry || $expiry > $now ) {
2259                                                 // Apply the restrictions
2260                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2261                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2262                                         } else { // Get rid of the old restrictions
2263                                                 Title::purgeExpiredRestrictions();
2264                                                 $this->mTitleProtection = false;
2265                                         }
2266                                 } else {
2267                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2268                                 }
2269                                 $this->mRestrictionsLoaded = true;
2270                         }
2271                 }
2272         }
2273
2274         /**
2275          * Purge expired restrictions from the page_restrictions table
2276          */
2277         static function purgeExpiredRestrictions() {
2278                 $dbw = wfGetDB( DB_MASTER );
2279                 $dbw->delete(
2280                         'page_restrictions',
2281                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2282                         __METHOD__
2283                 );
2284
2285                 $dbw->delete(
2286                         'protected_titles',
2287                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2288                         __METHOD__
2289                 );
2290         }
2291
2292         /**
2293          * Accessor/initialisation for mRestrictions
2294          *
2295          * @param $action String action that permission needs to be checked for
2296          * @return Array of Strings the array of groups allowed to edit this article
2297          */
2298         public function getRestrictions( $action ) {
2299                 if ( !$this->mRestrictionsLoaded ) {
2300                         $this->loadRestrictions();
2301                 }
2302                 return isset( $this->mRestrictions[$action] )
2303                                 ? $this->mRestrictions[$action]
2304                                 : array();
2305         }
2306
2307         /**
2308          * Get the expiry time for the restriction against a given action
2309          *
2310          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2311          *      or not protected at all, or false if the action is not recognised.
2312          */
2313         public function getRestrictionExpiry( $action ) {
2314                 if ( !$this->mRestrictionsLoaded ) {
2315                         $this->loadRestrictions();
2316                 }
2317                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2318         }
2319
2320         /**
2321          * Is there a version of this page in the deletion archive?
2322          *
2323          * @return Int the number of archived revisions
2324          */
2325         public function isDeleted() {
2326                 if ( $this->getNamespace() < 0 ) {
2327                         $n = 0;
2328                 } else {
2329                         $dbr = wfGetDB( DB_SLAVE );
2330                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2331                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2332                                 __METHOD__
2333                         );
2334                         if ( $this->getNamespace() == NS_FILE ) {
2335                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2336                                         array( 'fa_name' => $this->getDBkey() ),
2337                                         __METHOD__
2338                                 );
2339                         }
2340                 }
2341                 return (int)$n;
2342         }
2343
2344         /**
2345          * Is there a version of this page in the deletion archive?
2346          *
2347          * @return Boolean
2348          */
2349         public function isDeletedQuick() {
2350                 if ( $this->getNamespace() < 0 ) {
2351                         return false;
2352                 }
2353                 $dbr = wfGetDB( DB_SLAVE );
2354                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2355                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2356                         __METHOD__
2357                 );
2358                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2359                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2360                                 array( 'fa_name' => $this->getDBkey() ),
2361                                 __METHOD__
2362                         );
2363                 }
2364                 return $deleted;
2365         }
2366
2367         /**
2368          * Get the article ID for this Title from the link cache,
2369          * adding it if necessary
2370          *
2371          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2372          *  for update
2373          * @return Int the ID
2374          */
2375         public function getArticleID( $flags = 0 ) {
2376                 if ( $this->getNamespace() < 0 ) {
2377                         return $this->mArticleID = 0;
2378                 }
2379                 $linkCache = LinkCache::singleton();
2380                 if ( $flags & self::GAID_FOR_UPDATE ) {
2381                         $oldUpdate = $linkCache->forUpdate( true );
2382                         $linkCache->clearLink( $this );
2383                         $this->mArticleID = $linkCache->addLinkObj( $this );
2384                         $linkCache->forUpdate( $oldUpdate );
2385                 } else {
2386                         if ( -1 == $this->mArticleID ) {
2387                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2388                         }
2389                 }
2390                 return $this->mArticleID;
2391         }
2392
2393         /**
2394          * Is this an article that is a redirect page?
2395          * Uses link cache, adding it if necessary
2396          *
2397          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2398          * @return Bool
2399          */
2400         public function isRedirect( $flags = 0 ) {
2401                 if ( !is_null( $this->mRedirect ) ) {
2402                         return $this->mRedirect;
2403                 }
2404                 # Calling getArticleID() loads the field from cache as needed
2405                 if ( !$this->getArticleID( $flags ) ) {
2406                         return $this->mRedirect = false;
2407                 }
2408                 $linkCache = LinkCache::singleton();
2409                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2410
2411                 return $this->mRedirect;
2412         }
2413
2414         /**
2415          * What is the length of this page?
2416          * Uses link cache, adding it if necessary
2417          *
2418          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2419          * @return Int
2420          */
2421         public function getLength( $flags = 0 ) {
2422                 if ( $this->mLength != -1 ) {
2423                         return $this->mLength;
2424                 }
2425                 # Calling getArticleID() loads the field from cache as needed
2426                 if ( !$this->getArticleID( $flags ) ) {
2427                         return $this->mLength = 0;
2428                 }
2429                 $linkCache = LinkCache::singleton();
2430                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2431
2432                 return $this->mLength;
2433         }
2434
2435         /**
2436          * What is the page_latest field for this page?
2437          *
2438          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2439          * @return Int or 0 if the page doesn't exist
2440          */
2441         public function getLatestRevID( $flags = 0 ) {
2442                 if ( $this->mLatestID !== false ) {
2443                         return intval( $this->mLatestID );
2444                 }
2445                 # Calling getArticleID() loads the field from cache as needed
2446                 if ( !$this->getArticleID( $flags ) ) {
2447                         return $this->mLatestID = 0;
2448                 }
2449                 $linkCache = LinkCache::singleton();
2450                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2451
2452                 return $this->mLatestID;
2453         }
2454
2455         /**
2456          * This clears some fields in this object, and clears any associated
2457          * keys in the "bad links" section of the link cache.
2458          *
2459          * - This is called from Article::doEdit() and Article::insertOn() to allow
2460          * loading of the new page_id. It's also called from
2461          * Article::doDeleteArticle()
2462          *
2463          * @param $newid Int the new Article ID
2464          */
2465         public function resetArticleID( $newid ) {
2466                 $linkCache = LinkCache::singleton();
2467                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2468
2469                 if ( $newid === false ) {
2470                         $this->mArticleID = -1;
2471                 } else {
2472                         $this->mArticleID = intval( $newid );
2473                 }
2474                 $this->mRestrictionsLoaded = false;
2475                 $this->mRestrictions = array();
2476                 $this->mRedirect = null;
2477                 $this->mLength = -1;
2478                 $this->mLatestID = false;
2479         }
2480
2481         /**
2482          * Updates page_touched for this page; called from LinksUpdate.php
2483          *
2484          * @return Bool true if the update succeded
2485          */
2486         public function invalidateCache() {
2487                 if ( wfReadOnly() ) {
2488                         return;
2489                 }
2490                 $dbw = wfGetDB( DB_MASTER );
2491                 $success = $dbw->update(
2492                         'page',
2493                         array( 'page_touched' => $dbw->timestamp() ),
2494                         $this->pageCond(),
2495                         __METHOD__
2496                 );
2497                 HTMLFileCache::clearFileCache( $this );
2498                 return $success;
2499         }
2500
2501         /**
2502          * Prefix some arbitrary text with the namespace or interwiki prefix
2503          * of this object
2504          *
2505          * @param $name String the text
2506          * @return String the prefixed text
2507          * @private
2508          */
2509         /* private */ function prefix( $name ) {
2510                 $p = '';
2511                 if ( $this->mInterwiki != '' ) {
2512                         $p = $this->mInterwiki . ':';
2513                 }
2514
2515                 if ( 0 != $this->mNamespace ) {
2516                         $p .= $this->getNsText() . ':';
2517                 }
2518                 return $p . $name;
2519         }
2520
2521         /**
2522          * Returns a simple regex that will match on characters and sequences invalid in titles.
2523          * Note that this doesn't pick up many things that could be wrong with titles, but that
2524          * replacing this regex with something valid will make many titles valid.
2525          *
2526          * @return String regex string
2527          */
2528         static function getTitleInvalidRegex() {
2529                 static $rxTc = false;
2530                 if ( !$rxTc ) {
2531                         # Matching titles will be held as illegal.
2532                         $rxTc = '/' .
2533                                 # Any character not allowed is forbidden...
2534                                 '[^' . Title::legalChars() . ']' .
2535                                 # URL percent encoding sequences interfere with the ability
2536                                 # to round-trip titles -- you can't link to them consistently.
2537                                 '|%[0-9A-Fa-f]{2}' .
2538                                 # XML/HTML character references produce similar issues.
2539                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2540                                 '|&#[0-9]+;' .
2541                                 '|&#x[0-9A-Fa-f]+;' .
2542                                 '/S';
2543                 }
2544
2545                 return $rxTc;
2546         }
2547
2548         /**
2549          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2550          *
2551          * @param $text String containing title to capitalize
2552          * @param $ns int namespace index, defaults to NS_MAIN
2553          * @return String containing capitalized title
2554          */
2555         public static function capitalize( $text, $ns = NS_MAIN ) {
2556                 global $wgContLang;
2557
2558                 if ( MWNamespace::isCapitalized( $ns ) ) {
2559                         return $wgContLang->ucfirst( $text );
2560                 } else {
2561                         return $text;
2562                 }
2563         }
2564
2565         /**
2566          * Secure and split - main initialisation function for this object
2567          *
2568          * Assumes that mDbkeyform has been set, and is urldecoded
2569          * and uses underscores, but not otherwise munged.  This function
2570          * removes illegal characters, splits off the interwiki and
2571          * namespace prefixes, sets the other forms, and canonicalizes
2572          * everything.
2573          *
2574          * @return Bool true on success
2575          */
2576         private function secureAndSplit() {
2577                 global $wgContLang, $wgLocalInterwiki;
2578
2579                 # Initialisation
2580                 $rxTc = self::getTitleInvalidRegex();
2581
2582                 $this->mInterwiki = $this->mFragment = '';
2583                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2584
2585                 $dbkey = $this->mDbkeyform;
2586
2587                 # Strip Unicode bidi override characters.
2588                 # Sometimes they slip into cut-n-pasted page titles, where the
2589                 # override chars get included in list displays.
2590                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2591
2592                 # Clean up whitespace
2593                 # Note: use of the /u option on preg_replace here will cause
2594                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2595                 # conveniently disabling them.
2596                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2597                 $dbkey = trim( $dbkey, '_' );
2598
2599                 if ( $dbkey == '' ) {
2600                         return false;
2601                 }
2602
2603                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2604                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2605                         return false;
2606                 }
2607
2608                 $this->mDbkeyform = $dbkey;
2609
2610                 # Initial colon indicates main namespace rather than specified default
2611                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2612                 if ( ':' == $dbkey { 0 } ) {
2613                         $this->mNamespace = NS_MAIN;
2614                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2615                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2616                 }
2617
2618                 # Namespace or interwiki prefix
2619                 $firstPass = true;
2620                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2621                 do {
2622                         $m = array();
2623                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2624                                 $p = $m[1];
2625                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2626                                         # Ordinary namespace
2627                                         $dbkey = $m[2];
2628                                         $this->mNamespace = $ns;
2629                                         # For Talk:X pages, check if X has a "namespace" prefix
2630                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2631                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2632                                                         # Disallow Talk:File:x type titles...
2633                                                         return false;
2634                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2635                                                         # Disallow Talk:Interwiki:x type titles...
2636                                                         return false;
2637                                                 }
2638                                         }
2639                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2640                                         if ( !$firstPass ) {
2641                                                 # Can't make a local interwiki link to an interwiki link.
2642                                                 # That's just crazy!
2643                                                 return false;
2644                                         }
2645
2646                                         # Interwiki link
2647                                         $dbkey = $m[2];
2648                                         $this->mInterwiki = $wgContLang->lc( $p );
2649
2650                                         # Redundant interwiki prefix to the local wiki
2651                                         if ( $wgLocalInterwiki !== false
2652                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2653                                         {
2654                                                 if ( $dbkey == '' ) {
2655                                                         # Can't have an empty self-link
2656                                                         return false;
2657                                                 }
2658                                                 $this->mInterwiki = '';
2659                                                 $firstPass = false;
2660                                                 # Do another namespace split...
2661                                                 continue;
2662                                         }
2663
2664                                         # If there's an initial colon after the interwiki, that also
2665                                         # resets the default namespace
2666                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2667                                                 $this->mNamespace = NS_MAIN;
2668                                                 $dbkey = substr( $dbkey, 1 );
2669                                         }
2670                                 }
2671                                 # If there's no recognized interwiki or namespace,
2672                                 # then let the colon expression be part of the title.
2673                         }
2674                         break;
2675                 } while ( true );
2676
2677                 # We already know that some pages won't be in the database!
2678                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2679                         $this->mArticleID = 0;
2680                 }
2681                 $fragment = strstr( $dbkey, '#' );
2682                 if ( false !== $fragment ) {
2683                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2684                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2685                         # remove whitespace again: prevents "Foo_bar_#"
2686                         # becoming "Foo_bar_"
2687                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2688                 }
2689
2690                 # Reject illegal characters.
2691                 if ( preg_match( $rxTc, $dbkey ) ) {
2692                         return false;
2693                 }
2694
2695                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2696                 # reachable due to the way web browsers deal with 'relative' URLs.
2697                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2698                 if ( strpos( $dbkey, '.' ) !== false &&
2699                          ( $dbkey === '.' || $dbkey === '..' ||
2700                            strpos( $dbkey, './' ) === 0  ||
2701                            strpos( $dbkey, '../' ) === 0 ||
2702                            strpos( $dbkey, '/./' ) !== false ||
2703                            strpos( $dbkey, '/../' ) !== false  ||
2704                            substr( $dbkey, -2 ) == '/.' ||
2705                            substr( $dbkey, -3 ) == '/..' ) )
2706                 {
2707                         return false;
2708                 }
2709
2710                 # Magic tilde sequences? Nu-uh!
2711                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2712                         return false;
2713                 }
2714
2715                 # Limit the size of titles to 255 bytes. This is typically the size of the
2716                 # underlying database field. We make an exception for special pages, which
2717                 # don't need to be stored in the database, and may edge over 255 bytes due
2718                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2719                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2720                   strlen( $dbkey ) > 512 )
2721                 {
2722                         return false;
2723                 }
2724
2725                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2726                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2727                 # other site might be case-sensitive.
2728                 $this->mUserCaseDBKey = $dbkey;
2729                 if ( $this->mInterwiki == '' ) {
2730                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2731                 }
2732
2733                 # Can't make a link to a namespace alone... "empty" local links can only be
2734                 # self-links with a fragment identifier.
2735                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2736                         return false;
2737                 }
2738
2739                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2740                 // IP names are not allowed for accounts, and can only be referring to
2741                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2742                 // there are numerous ways to present the same IP. Having sp:contribs scan
2743                 // them all is silly and having some show the edits and others not is
2744                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2745                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2746                         ? IP::sanitizeIP( $dbkey )
2747                         : $dbkey;
2748
2749                 // Any remaining initial :s are illegal.
2750                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2751                         return false;
2752                 }
2753
2754                 # Fill fields
2755                 $this->mDbkeyform = $dbkey;
2756                 $this->mUrlform = wfUrlencode( $dbkey );
2757
2758                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2759
2760                 return true;
2761         }
2762
2763         /**
2764          * Set the fragment for this title. Removes the first character from the
2765          * specified fragment before setting, so it assumes you're passing it with
2766          * an initial "#".
2767          *
2768          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2769          * Still in active use privately.
2770          *
2771          * @param $fragment String text
2772          */
2773         public function setFragment( $fragment ) {
2774                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2775         }
2776
2777         /**
2778          * Get a Title object associated with the talk page of this article
2779          *
2780          * @return Title the object for the talk page
2781          */
2782         public function getTalkPage() {
2783                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2784         }
2785
2786         /**
2787          * Get a title object associated with the subject page of this
2788          * talk page
2789          *
2790          * @return Title the object for the subject page
2791          */
2792         public function getSubjectPage() {
2793                 // Is this the same title?
2794                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2795                 if ( $this->getNamespace() == $subjectNS ) {
2796                         return $this;
2797                 }
2798                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2799         }
2800
2801         /**
2802          * Get an array of Title objects linking to this Title
2803          * Also stores the IDs in the link cache.
2804          *
2805          * WARNING: do not use this function on arbitrary user-supplied titles!
2806          * On heavily-used templates it will max out the memory.
2807          *
2808          * @param $options Array: may be FOR UPDATE
2809          * @param $table String: table name
2810          * @param $prefix String: fields prefix
2811          * @return Array of Title objects linking here
2812          */
2813         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2814                 $linkCache = LinkCache::singleton();
2815
2816                 if ( count( $options ) > 0 ) {
2817                         $db = wfGetDB( DB_MASTER );
2818                 } else {
2819                         $db = wfGetDB( DB_SLAVE );
2820                 }
2821
2822                 $res = $db->select(
2823                         array( 'page', $table ),
2824                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2825                         array(
2826                                 "{$prefix}_from=page_id",
2827                                 "{$prefix}_namespace" => $this->getNamespace(),
2828                                 "{$prefix}_title"     => $this->getDBkey() ),
2829                         __METHOD__,
2830                         $options
2831                 );
2832
2833                 $retVal = array();
2834                 if ( $db->numRows( $res ) ) {
2835                         foreach ( $res as $row ) {
2836                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2837                                 if ( $titleObj ) {
2838                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2839                                         $retVal[] = $titleObj;
2840                                 }
2841                         }
2842                 }
2843                 return $retVal;
2844         }
2845
2846         /**
2847          * Get an array of Title objects using this Title as a template
2848          * Also stores the IDs in the link cache.
2849          *
2850          * WARNING: do not use this function on arbitrary user-supplied titles!
2851          * On heavily-used templates it will max out the memory.
2852          *
2853          * @param $options Array: may be FOR UPDATE
2854          * @return Array of Title the Title objects linking here
2855          */
2856         public function getTemplateLinksTo( $options = array() ) {
2857                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2858         }
2859
2860         /**
2861          * Get an array of Title objects referring to non-existent articles linked from this page
2862          *
2863          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2864          * @return Array of Title the Title objects
2865          */
2866         public function getBrokenLinksFrom() {
2867                 if ( $this->getArticleId() == 0 ) {
2868                         # All links from article ID 0 are false positives
2869                         return array();
2870                 }
2871
2872                 $dbr = wfGetDB( DB_SLAVE );
2873                 $res = $dbr->select(
2874                         array( 'page', 'pagelinks' ),
2875                         array( 'pl_namespace', 'pl_title' ),
2876                         array(
2877                                 'pl_from' => $this->getArticleId(),
2878                                 'page_namespace IS NULL'
2879                         ),
2880                         __METHOD__, array(),
2881                         array(
2882                                 'page' => array(
2883                                         'LEFT JOIN',
2884                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2885                                 )
2886                         )
2887                 );
2888
2889                 $retVal = array();
2890                 foreach ( $res as $row ) {
2891                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2892                 }
2893                 return $retVal;
2894         }
2895
2896
2897         /**
2898          * Get a list of URLs to purge from the Squid cache when this
2899          * page changes
2900          *
2901          * @return Array of String the URLs
2902          */
2903         public function getSquidURLs() {
2904                 global $wgContLang;
2905
2906                 $urls = array(
2907                         $this->getInternalURL(),
2908                         $this->getInternalURL( 'action=history' )
2909                 );
2910
2911                 // purge variant urls as well
2912                 if ( $wgContLang->hasVariants() ) {
2913                         $variants = $wgContLang->getVariants();
2914                         foreach ( $variants as $vCode ) {
2915                                 $urls[] = $this->getInternalURL( '', $vCode );
2916                         }
2917                 }
2918
2919                 return $urls;
2920         }
2921
2922         /**
2923          * Purge all applicable Squid URLs
2924          */
2925         public function purgeSquid() {
2926                 global $wgUseSquid;
2927                 if ( $wgUseSquid ) {
2928                         $urls = $this->getSquidURLs();
2929                         $u = new SquidUpdate( $urls );
2930                         $u->doUpdate();
2931                 }
2932         }
2933
2934         /**
2935          * Move this page without authentication
2936          *
2937          * @param $nt Title the new page Title
2938          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2939          */
2940         public function moveNoAuth( &$nt ) {
2941                 return $this->moveTo( $nt, false );
2942         }
2943
2944         /**
2945          * Check whether a given move operation would be valid.
2946          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2947          *
2948          * @param $nt Title the new title
2949          * @param $auth Bool indicates whether $wgUser's permissions
2950          *  should be checked
2951          * @param $reason String is the log summary of the move, used for spam checking
2952          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2953          */
2954         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2955                 global $wgUser;
2956
2957                 $errors = array();
2958                 if ( !$nt ) {
2959                         // Normally we'd add this to $errors, but we'll get
2960                         // lots of syntax errors if $nt is not an object
2961                         return array( array( 'badtitletext' ) );
2962                 }
2963                 if ( $this->equals( $nt ) ) {
2964                         $errors[] = array( 'selfmove' );
2965                 }
2966                 if ( !$this->isMovable() ) {
2967                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2968                 }
2969                 if ( $nt->getInterwiki() != '' ) {
2970                         $errors[] = array( 'immobile-target-namespace-iw' );
2971                 }
2972                 if ( !$nt->isMovable() ) {
2973                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2974                 }
2975
2976                 $oldid = $this->getArticleID();
2977                 $newid = $nt->getArticleID();
2978
2979                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2980                         $errors[] = array( 'articleexists' );
2981                 }
2982                 if ( ( $this->getDBkey() == '' ) ||
2983                          ( !$oldid ) ||
2984                          ( $nt->getDBkey() == '' ) ) {
2985                         $errors[] = array( 'badarticleerror' );
2986                 }
2987
2988                 // Image-specific checks
2989                 if ( $this->getNamespace() == NS_FILE ) {
2990                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
2991                 }
2992
2993                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2994                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2995                 }
2996
2997                 if ( $auth ) {
2998                         $errors = wfMergeErrorArrays( $errors,
2999                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3000                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3001                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3002                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3003                 }
3004
3005                 $match = EditPage::matchSummarySpamRegex( $reason );
3006                 if ( $match !== false ) {
3007                         // This is kind of lame, won't display nice
3008                         $errors[] = array( 'spamprotectiontext' );
3009                 }
3010
3011                 $err = null;
3012                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3013                         $errors[] = array( 'hookaborted', $err );
3014                 }
3015
3016                 # The move is allowed only if (1) the target doesn't exist, or
3017                 # (2) the target is a redirect to the source, and has no history
3018                 # (so we can undo bad moves right after they're done).
3019
3020                 if ( 0 != $newid ) { # Target exists; check for validity
3021                         if ( !$this->isValidMoveTarget( $nt ) ) {
3022                                 $errors[] = array( 'articleexists' );
3023                         }
3024                 } else {
3025                         $tp = $nt->getTitleProtection();
3026                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3027                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3028                                 $errors[] = array( 'cantmove-titleprotected' );
3029                         }
3030                 }
3031                 if ( empty( $errors ) ) {
3032                         return true;
3033                 }
3034                 return $errors;
3035         }
3036
3037         /**
3038          * Check if the requested move target is a valid file move target
3039          * @param Title $nt Target title
3040          * @return array List of errors
3041          */
3042         protected function validateFileMoveOperation( $nt ) {
3043                 global $wgUser;
3044
3045                 $errors = array();
3046
3047                 if ( $nt->getNamespace() != NS_FILE ) {
3048                         $errors[] = array( 'imagenocrossnamespace' );
3049                 }
3050
3051                 $file = wfLocalFile( $this );
3052                 if ( $file->exists() ) {
3053                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3054                                 $errors[] = array( 'imageinvalidfilename' );
3055                         }
3056                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3057                                 $errors[] = array( 'imagetypemismatch' );
3058                         }
3059                 }
3060
3061                 $destFile = wfLocalFile( $nt );
3062                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3063                         $errors[] = array( 'file-exists-sharedrepo' );
3064                 }
3065
3066                 return $errors;
3067         }
3068
3069         /**
3070          * Move a title to a new location
3071          *
3072          * @param $nt Title the new title
3073          * @param $auth Bool indicates whether $wgUser's permissions
3074          *  should be checked
3075          * @param $reason String the reason for the move
3076          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3077          *  Ignored if the user doesn't have the suppressredirect right.
3078          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3079          */
3080         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3081                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3082                 if ( is_array( $err ) ) {
3083                         return $err;
3084                 }
3085
3086                 // If it is a file, move it first. It is done before all other moving stuff is
3087                 // done because it's hard to revert
3088                 $dbw = wfGetDB( DB_MASTER );
3089                 if ( $this->getNamespace() == NS_FILE ) {
3090                         $file = wfLocalFile( $this );
3091                         if ( $file->exists() ) {
3092                                 $status = $file->move( $nt );
3093                                 if ( !$status->isOk() ) {
3094                                         return $status->getErrorsArray();
3095                                 }
3096                         }
3097                 }
3098
3099                 $pageid = $this->getArticleID();
3100                 $protected = $this->isProtected();
3101                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3102
3103                 // Do the actual move
3104                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3105                 if ( is_array( $err ) ) {
3106                         return $err;
3107                 }
3108
3109                 $redirid = $this->getArticleID();
3110
3111                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3112                 // cl_timestamp, which may disturb time-based lists on some sites.
3113                 $prefix = $dbw->selectField(
3114                         'categorylinks',
3115                         'cl_sortkey_prefix',
3116                         array( 'cl_from' => $pageid ),
3117                         __METHOD__
3118                 );
3119                 $dbw->update( 'categorylinks',
3120                         array(
3121                                 'cl_sortkey' => Collation::singleton()->getSortKey(
3122                                         $nt->getCategorySortkey( $prefix ) ),
3123                                 'cl_timestamp=cl_timestamp' ),
3124                         array( 'cl_from' => $pageid ),
3125                         __METHOD__ );
3126
3127                 if ( $protected ) {
3128                         # Protect the redirect title as the title used to be...
3129                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3130                                 array(
3131                                         'pr_page'    => $redirid,
3132                                         'pr_type'    => 'pr_type',
3133                                         'pr_level'   => 'pr_level',
3134                                         'pr_cascade' => 'pr_cascade',
3135                                         'pr_user'    => 'pr_user',
3136                                         'pr_expiry'  => 'pr_expiry'
3137                                 ),
3138                                 array( 'pr_page' => $pageid ),
3139                                 __METHOD__,
3140                                 array( 'IGNORE' )
3141                         );
3142                         # Update the protection log
3143                         $log = new LogPage( 'protect' );
3144                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3145                         if ( $reason ) {
3146                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3147                         }
3148                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3149                 }
3150
3151                 # Update watchlists
3152                 $oldnamespace = $this->getNamespace() & ~1;
3153                 $newnamespace = $nt->getNamespace() & ~1;
3154                 $oldtitle = $this->getDBkey();
3155                 $newtitle = $nt->getDBkey();
3156
3157                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3158                         WatchedItem::duplicateEntries( $this, $nt );
3159                 }
3160
3161                 # Update search engine
3162                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3163                 $u->doUpdate();
3164                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3165                 $u->doUpdate();
3166
3167                 # Update site_stats
3168                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3169                         # No longer a content page
3170                         # Not viewed, edited, removing
3171                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3172                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3173                         # Now a content page
3174                         # Not viewed, edited, adding
3175                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3176                 } elseif ( $pageCountChange ) {
3177                         # Redirect added
3178                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3179                 } else {
3180                         # Nothing special
3181                         $u = false;
3182                 }
3183                 if ( $u ) {
3184                         $u->doUpdate();
3185                 }
3186                 # Update message cache for interface messages
3187                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3188                         # @bug 17860: old article can be deleted, if this the case,
3189                         # delete it from message cache
3190                         if ( $this->getArticleID() === 0 ) {
3191                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3192                         } else {
3193                                 $oldarticle = new Article( $this );
3194                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3195                         }
3196                 }
3197                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3198                         $newarticle = new Article( $nt );
3199                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3200                 }
3201
3202                 global $wgUser;
3203                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3204                 return true;
3205         }
3206
3207         /**
3208          * Move page to a title which is either a redirect to the
3209          * source page or nonexistent
3210          *
3211          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3212          * @param $reason String The reason for the move
3213          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3214          *   if the user doesn't have the suppressredirect right
3215          */
3216         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3217                 global $wgUser, $wgContLang;
3218
3219                 $moveOverRedirect = $nt->exists();
3220
3221                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3222                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3223
3224                 if ( $reason ) {
3225                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3226                 }
3227                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3228                 $comment = $wgContLang->truncate( $comment, 250 );
3229
3230                 $oldid = $this->getArticleID();
3231                 $latest = $this->getLatestRevID();
3232
3233                 $dbw = wfGetDB( DB_MASTER );
3234
3235                 if ( $moveOverRedirect ) {
3236                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3237
3238                         $newid = $nt->getArticleID();
3239                         $newns = $nt->getNamespace();
3240                         $newdbk = $nt->getDBkey();
3241
3242                         # Delete the old redirect. We don't save it to history since
3243                         # by definition if we've got here it's rather uninteresting.
3244                         # We have to remove it so that the next step doesn't trigger
3245                         # a conflict on the unique namespace+title index...
3246                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3247                         if ( !$dbw->cascadingDeletes() ) {
3248                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3249                                 global $wgUseTrackbacks;
3250                                 if ( $wgUseTrackbacks ) {
3251                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3252                                 }
3253                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3254                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3255                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3256                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3257                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3258                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3259                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3260                         }
3261                         // If the target page was recently created, it may have an entry in recentchanges still
3262                         $dbw->delete( 'recentchanges',
3263                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3264                                 __METHOD__
3265                         );
3266                 }
3267
3268                 # Save a null revision in the page's history notifying of the move
3269                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3270                 if ( !is_object( $nullRevision ) ) {
3271                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3272                 }
3273                 $nullRevId = $nullRevision->insertOn( $dbw );
3274
3275                 $article = new Article( $this );
3276                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3277
3278                 # Change the name of the target page:
3279                 $dbw->update( 'page',
3280                         /* SET */ array(
3281                                 'page_touched'   => $dbw->timestamp(),
3282                                 'page_namespace' => $nt->getNamespace(),
3283                                 'page_title'     => $nt->getDBkey(),
3284                                 'page_latest'    => $nullRevId,
3285                         ),
3286                         /* WHERE */ array( 'page_id' => $oldid ),
3287                         __METHOD__
3288                 );
3289                 $nt->resetArticleID( $oldid );
3290
3291                 # Recreate the redirect, this time in the other direction.
3292                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3293                         $mwRedir = MagicWord::get( 'redirect' );
3294                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3295                         $redirectArticle = new Article( $this );
3296                         $newid = $redirectArticle->insertOn( $dbw );
3297                         $redirectRevision = new Revision( array(
3298                                 'page'    => $newid,
3299                                 'comment' => $comment,
3300                                 'text'    => $redirectText ) );
3301                         $redirectRevision->insertOn( $dbw );
3302                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3303
3304                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3305
3306                         # Now, we record the link from the redirect to the new title.
3307                         # It should have no other outgoing links...
3308                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3309                         $dbw->insert( 'pagelinks',
3310                                 array(
3311                                         'pl_from'      => $newid,
3312                                         'pl_namespace' => $nt->getNamespace(),
3313                                         'pl_title'     => $nt->getDBkey() ),
3314                                 __METHOD__ );
3315                         $redirectSuppressed = false;
3316                 } else {
3317                         $this->resetArticleID( 0 );
3318                         $redirectSuppressed = true;
3319                 }
3320
3321                 # Log the move
3322                 $log = new LogPage( 'move' );
3323                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3324                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3325
3326                 # Purge caches for old and new titles
3327                 if ( $moveOverRedirect ) {
3328                         # A simple purge is enough when moving over a redirect
3329                         $nt->purgeSquid();
3330                 } else {
3331                         # Purge caches as per article creation, including any pages that link to this title
3332                         Article::onArticleCreate( $nt );
3333                 }
3334                 $this->purgeSquid();
3335         }
3336
3337         /**
3338          * Move this page's subpages to be subpages of $nt
3339          *
3340          * @param $nt Title Move target
3341          * @param $auth bool Whether $wgUser's permissions should be checked
3342          * @param $reason string The reason for the move
3343          * @param $createRedirect bool Whether to create redirects from the old subpages to
3344          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3345          * @return mixed array with old page titles as keys, and strings (new page titles) or
3346          *     arrays (errors) as values, or an error array with numeric indices if no pages
3347          *     were moved
3348          */
3349         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3350                 global $wgMaximumMovedPages;
3351                 // Check permissions
3352                 if ( !$this->userCan( 'move-subpages' ) ) {
3353                         return array( 'cant-move-subpages' );
3354                 }
3355                 // Do the source and target namespaces support subpages?
3356                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3357                         return array( 'namespace-nosubpages',
3358                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3359                 }
3360                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3361                         return array( 'namespace-nosubpages',
3362                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3363                 }
3364
3365                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3366                 $retval = array();
3367                 $count = 0;
3368                 foreach ( $subpages as $oldSubpage ) {
3369                         $count++;
3370                         if ( $count > $wgMaximumMovedPages ) {
3371                                 $retval[$oldSubpage->getPrefixedTitle()] =
3372                                                 array( 'movepage-max-pages',
3373                                                         $wgMaximumMovedPages );
3374                                 break;
3375                         }
3376
3377                         // We don't know whether this function was called before
3378                         // or after moving the root page, so check both
3379                         // $this and $nt
3380                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3381                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3382                         {
3383                                 // When moving a page to a subpage of itself,
3384                                 // don't move it twice
3385                                 continue;
3386                         }
3387                         $newPageName = preg_replace(
3388                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3389                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3390                                         $oldSubpage->getDBkey() );
3391                         if ( $oldSubpage->isTalkPage() ) {
3392                                 $newNs = $nt->getTalkPage()->getNamespace();
3393                         } else {
3394                                 $newNs = $nt->getSubjectPage()->getNamespace();
3395                         }
3396                         # Bug 14385: we need makeTitleSafe because the new page names may
3397                         # be longer than 255 characters.
3398                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3399
3400                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3401                         if ( $success === true ) {
3402                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3403                         } else {
3404                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3405                         }
3406                 }
3407                 return $retval;
3408         }
3409
3410         /**
3411          * Checks if this page is just a one-rev redirect.
3412          * Adds lock, so don't use just for light purposes.
3413          *
3414          * @return Bool
3415          */
3416         public function isSingleRevRedirect() {
3417                 $dbw = wfGetDB( DB_MASTER );
3418                 # Is it a redirect?
3419                 $row = $dbw->selectRow( 'page',
3420                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3421                         $this->pageCond(),
3422                         __METHOD__,
3423                         array( 'FOR UPDATE' )
3424                 );
3425                 # Cache some fields we may want
3426                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3427                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3428                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3429                 if ( !$this->mRedirect ) {
3430                         return false;
3431                 }
3432                 # Does the article have a history?
3433                 $row = $dbw->selectField( array( 'page', 'revision' ),
3434                         'rev_id',
3435                         array( 'page_namespace' => $this->getNamespace(),
3436                                 'page_title' => $this->getDBkey(),
3437                                 'page_id=rev_page',
3438                                 'page_latest != rev_id'
3439                         ),
3440                         __METHOD__,
3441                         array( 'FOR UPDATE' )
3442                 );
3443                 # Return true if there was no history
3444                 return ( $row === false );
3445         }
3446
3447         /**
3448          * Checks if $this can be moved to a given Title
3449          * - Selects for update, so don't call it unless you mean business
3450          *
3451          * @param $nt Title the new title to check
3452          * @return Bool
3453          */
3454         public function isValidMoveTarget( $nt ) {
3455                 # Is it an existing file?
3456                 if ( $nt->getNamespace() == NS_FILE ) {
3457                         $file = wfLocalFile( $nt );
3458                         if ( $file->exists() ) {
3459                                 wfDebug( __METHOD__ . ": file exists\n" );
3460                                 return false;
3461                         }
3462                 }
3463                 # Is it a redirect with no history?
3464                 if ( !$nt->isSingleRevRedirect() ) {
3465                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3466                         return false;
3467                 }
3468                 # Get the article text
3469                 $rev = Revision::newFromTitle( $nt );
3470                 $text = $rev->getText();
3471                 # Does the redirect point to the source?
3472                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3473                 $m = array();
3474                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3475                         $redirTitle = Title::newFromText( $m[1] );
3476                         if ( !is_object( $redirTitle ) ||
3477                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3478                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3479                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3480                                 return false;
3481                         }
3482                 } else {
3483                         # Fail safe
3484                         wfDebug( __METHOD__ . ": failsafe\n" );
3485                         return false;
3486                 }
3487                 return true;
3488         }
3489
3490         /**
3491          * Can this title be added to a user's watchlist?
3492          *
3493          * @return Bool TRUE or FALSE
3494          */
3495         public function isWatchable() {
3496                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3497         }
3498
3499         /**
3500          * Get categories to which this Title belongs and return an array of
3501          * categories' names.
3502          *
3503          * @return Array of parents in the form:
3504          *        $parent => $currentarticle
3505          */
3506         public function getParentCategories() {
3507                 global $wgContLang;
3508
3509                 $data = array();
3510
3511                 $titleKey = $this->getArticleId();
3512
3513                 if ( $titleKey === 0 ) {
3514                         return $data;
3515                 }
3516
3517                 $dbr = wfGetDB( DB_SLAVE );
3518
3519                 $res = $dbr->select( 'categorylinks', '*',
3520                         array(
3521                                 'cl_from' => $titleKey,
3522                         ),
3523                         __METHOD__,
3524                         array()
3525                 );
3526
3527                 if ( $dbr->numRows( $res ) > 0 ) {
3528                         foreach ( $res as $row ) {
3529                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3530                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3531                         }
3532                 }
3533                 return $data;
3534         }
3535
3536         /**
3537          * Get a tree of parent categories
3538          *
3539          * @param $children Array with the children in the keys, to check for circular refs
3540          * @return Array Tree of parent categories
3541          */
3542         public function getParentCategoryTree( $children = array() ) {
3543                 $stack = array();
3544                 $parents = $this->getParentCategories();
3545
3546                 if ( $parents ) {
3547                         foreach ( $parents as $parent => $current ) {
3548                                 if ( array_key_exists( $parent, $children ) ) {
3549                                         # Circular reference
3550                                         $stack[$parent] = array();
3551                                 } else {
3552                                         $nt = Title::newFromText( $parent );
3553                                         if ( $nt ) {
3554                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3555                                         }
3556                                 }
3557                         }
3558                 }
3559
3560                 return $stack;
3561         }
3562
3563         /**
3564          * Get an associative array for selecting this title from
3565          * the "page" table
3566          *
3567          * @return Array suitable for the $where parameter of DB::select()
3568          */
3569         public function pageCond() {
3570                 if ( $this->mArticleID > 0 ) {
3571                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3572                         return array( 'page_id' => $this->mArticleID );
3573                 } else {
3574                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3575                 }
3576         }
3577
3578         /**
3579          * Get the revision ID of the previous revision
3580          *
3581          * @param $revId Int Revision ID. Get the revision that was before this one.
3582          * @param $flags Int Title::GAID_FOR_UPDATE
3583          * @return Int|Bool Old revision ID, or FALSE if none exists
3584          */
3585         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3586                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3587                 return $db->selectField( 'revision', 'rev_id',
3588                         array(
3589                                 'rev_page' => $this->getArticleId( $flags ),
3590                                 'rev_id < ' . intval( $revId )
3591                         ),
3592                         __METHOD__,
3593                         array( 'ORDER BY' => 'rev_id DESC' )
3594                 );
3595         }
3596
3597         /**
3598          * Get the revision ID of the next revision
3599          *
3600          * @param $revId Int Revision ID. Get the revision that was after this one.
3601          * @param $flags Int Title::GAID_FOR_UPDATE
3602          * @return Int|Bool Next revision ID, or FALSE if none exists
3603          */
3604         public function getNextRevisionID( $revId, $flags = 0 ) {
3605                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3606                 return $db->selectField( 'revision', 'rev_id',
3607                         array(
3608                                 'rev_page' => $this->getArticleId( $flags ),
3609                                 'rev_id > ' . intval( $revId )
3610                         ),
3611                         __METHOD__,
3612                         array( 'ORDER BY' => 'rev_id' )
3613                 );
3614         }
3615
3616         /**
3617          * Get the first revision of the page
3618          *
3619          * @param $flags Int Title::GAID_FOR_UPDATE
3620          * @return Revision|Null if page doesn't exist
3621          */
3622         public function getFirstRevision( $flags = 0 ) {
3623                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3624                 $pageId = $this->getArticleId( $flags );
3625                 if ( !$pageId ) {
3626                         return null;
3627                 }
3628                 $row = $db->selectRow( 'revision', '*',
3629                         array( 'rev_page' => $pageId ),
3630                         __METHOD__,
3631                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3632                 );
3633                 if ( !$row ) {
3634                         return null;
3635                 } else {
3636                         return new Revision( $row );
3637                 }
3638         }
3639
3640         /**
3641          * Check if this is a new page
3642          *
3643          * @return bool
3644          */
3645         public function isNewPage() {
3646                 $dbr = wfGetDB( DB_SLAVE );
3647                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3648         }
3649
3650         /**
3651          * Get the oldest revision timestamp of this page
3652          *
3653          * @return String: MW timestamp
3654          */
3655         public function getEarliestRevTime() {
3656                 $dbr = wfGetDB( DB_SLAVE );
3657                 if ( $this->exists() ) {
3658                         $min = $dbr->selectField( 'revision',
3659                                 'MIN(rev_timestamp)',
3660                                 array( 'rev_page' => $this->getArticleId() ),
3661                                 __METHOD__ );
3662                         return wfTimestampOrNull( TS_MW, $min );
3663                 }
3664                 return null;
3665         }
3666
3667         /**
3668          * Get the number of revisions between the given revision IDs.
3669          * Used for diffs and other things that really need it.
3670          *
3671          * @param $old Int Revision ID.
3672          * @param $new Int Revision ID.
3673          * @return Int Number of revisions between these IDs.
3674          */
3675         public function countRevisionsBetween( $old, $new ) {
3676                 $dbr = wfGetDB( DB_SLAVE );
3677                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3678                                 'rev_page' => intval( $this->getArticleId() ),
3679                                 'rev_id > ' . intval( $old ),
3680                                 'rev_id < ' . intval( $new )
3681                         ), __METHOD__
3682                 );
3683         }
3684
3685         /**
3686          * Get the number of authors between the given revision IDs.
3687          * Used for diffs and other things that really need it.
3688          *
3689          * @param $fromRevId Int Revision ID (first before range)
3690          * @param $toRevId Int Revision ID (first after range)
3691          * @param $limit Int Maximum number of authors
3692          * @param $flags Int Title::GAID_FOR_UPDATE
3693          * @return Int
3694          */
3695         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3696                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3697                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3698                         array(
3699                                 'rev_page' => $this->getArticleID(),
3700                                 'rev_id > ' . (int)$fromRevId,
3701                                 'rev_id < ' . (int)$toRevId
3702                         ), __METHOD__,
3703                         array( 'LIMIT' => $limit )
3704                 );
3705                 return (int)$db->numRows( $res );
3706         }
3707
3708         /**
3709          * Compare with another title.
3710          *
3711          * @param $title Title
3712          * @return Bool
3713          */
3714         public function equals( Title $title ) {
3715                 // Note: === is necessary for proper matching of number-like titles.
3716                 return $this->getInterwiki() === $title->getInterwiki()
3717                         && $this->getNamespace() == $title->getNamespace()
3718                         && $this->getDBkey() === $title->getDBkey();
3719         }
3720
3721         /**
3722          * Callback for usort() to do title sorts by (namespace, title)
3723          *
3724          * @param $a Title
3725          * @param $b Title
3726          *
3727          * @return Integer: result of string comparison, or namespace comparison
3728          */
3729         public static function compare( $a, $b ) {
3730                 if ( $a->getNamespace() == $b->getNamespace() ) {
3731                         return strcmp( $a->getText(), $b->getText() );
3732                 } else {
3733                         return $a->getNamespace() - $b->getNamespace();
3734                 }
3735         }
3736
3737         /**
3738          * Return a string representation of this title
3739          *
3740          * @return String representation of this title
3741          */
3742         public function __toString() {
3743                 return $this->getPrefixedText();
3744         }
3745
3746         /**
3747          * Check if page exists.  For historical reasons, this function simply
3748          * checks for the existence of the title in the page table, and will
3749          * thus return false for interwiki links, special pages and the like.
3750          * If you want to know if a title can be meaningfully viewed, you should
3751          * probably call the isKnown() method instead.
3752          *
3753          * @return Bool
3754          */
3755         public function exists() {
3756                 return $this->getArticleId() != 0;
3757         }
3758
3759         /**
3760          * Should links to this title be shown as potentially viewable (i.e. as
3761          * "bluelinks"), even if there's no record by this title in the page
3762          * table?
3763          *
3764          * This function is semi-deprecated for public use, as well as somewhat
3765          * misleadingly named.  You probably just want to call isKnown(), which
3766          * calls this function internally.
3767          *
3768          * (ISSUE: Most of these checks are cheap, but the file existence check
3769          * can potentially be quite expensive.  Including it here fixes a lot of
3770          * existing code, but we might want to add an optional parameter to skip
3771          * it and any other expensive checks.)
3772          *
3773          * @return Bool
3774          */
3775         public function isAlwaysKnown() {
3776                 if ( $this->mInterwiki != '' ) {
3777                         return true;  // any interwiki link might be viewable, for all we know
3778                 }
3779                 switch( $this->mNamespace ) {
3780                         case NS_MEDIA:
3781                         case NS_FILE:
3782                                 // file exists, possibly in a foreign repo
3783                                 return (bool)wfFindFile( $this );
3784                         case NS_SPECIAL:
3785                                 // valid special page
3786                                 return SpecialPage::exists( $this->getDBkey() );
3787                         case NS_MAIN:
3788                                 // selflink, possibly with fragment
3789                                 return $this->mDbkeyform == '';
3790                         case NS_MEDIAWIKI:
3791                                 // known system message
3792                                 return $this->getDefaultMessageText() !== false;
3793                         default:
3794                                 return false;
3795                 }
3796         }
3797
3798         /**
3799          * Does this title refer to a page that can (or might) be meaningfully
3800          * viewed?  In particular, this function may be used to determine if
3801          * links to the title should be rendered as "bluelinks" (as opposed to
3802          * "redlinks" to non-existent pages).
3803          *
3804          * @return Bool
3805          */
3806         public function isKnown() {
3807                 return $this->isAlwaysKnown() || $this->exists();
3808         }
3809
3810         /**
3811          * Does this page have source text?
3812          *
3813          * @return Boolean
3814          */
3815         public function hasSourceText() {
3816                 if ( $this->exists() ) {
3817                         return true;
3818                 }
3819
3820                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3821                         // If the page doesn't exist but is a known system message, default
3822                         // message content will be displayed, same for language subpages
3823                         return $this->getDefaultMessageText() !== false;
3824                 }
3825
3826                 return false;
3827         }
3828
3829         /**
3830          * Get the default message text or false if the message doesn't exist
3831          *
3832          * @return String or false
3833          */
3834         public function getDefaultMessageText() {
3835                 global $wgContLang;
3836
3837                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3838                         return false;
3839                 }
3840
3841                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3842                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3843
3844                 if ( $message->exists() ) {
3845                         return $message->plain();
3846                 } else {
3847                         return false;
3848                 }
3849         }
3850
3851         /**
3852          * Is this in a namespace that allows actual pages?
3853          *
3854          * @return Bool
3855          * @internal note -- uses hardcoded namespace index instead of constants
3856          */
3857         public function canExist() {
3858                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3859         }
3860
3861         /**
3862          * Update page_touched timestamps and send squid purge messages for
3863          * pages linking to this title. May be sent to the job queue depending
3864          * on the number of links. Typically called on create and delete.
3865          */
3866         public function touchLinks() {
3867                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3868                 $u->doUpdate();
3869
3870                 if ( $this->getNamespace() == NS_CATEGORY ) {
3871                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3872                         $u->doUpdate();
3873                 }
3874         }
3875
3876         /**
3877          * Get the last touched timestamp
3878          *
3879          * @param $db DatabaseBase: optional db
3880          * @return String last-touched timestamp
3881          */
3882         public function getTouched( $db = null ) {
3883                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3884                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3885                 return $touched;
3886         }
3887
3888         /**
3889          * Get the timestamp when this page was updated since the user last saw it.
3890          *
3891          * @param $user User
3892          * @return String|Null
3893          */
3894         public function getNotificationTimestamp( $user = null ) {
3895                 global $wgUser, $wgShowUpdatedMarker;
3896                 // Assume current user if none given
3897                 if ( !$user ) {
3898                         $user = $wgUser;
3899                 }
3900                 // Check cache first
3901                 $uid = $user->getId();
3902                 // avoid isset here, as it'll return false for null entries
3903                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3904                         return $this->mNotificationTimestamp[$uid];
3905                 }
3906                 if ( !$uid || !$wgShowUpdatedMarker ) {
3907                         return $this->mNotificationTimestamp[$uid] = false;
3908                 }
3909                 // Don't cache too much!
3910                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3911                         $this->mNotificationTimestamp = array();
3912                 }
3913                 $dbr = wfGetDB( DB_SLAVE );
3914                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3915                         'wl_notificationtimestamp',
3916                         array( 'wl_namespace' => $this->getNamespace(),
3917                                 'wl_title' => $this->getDBkey(),
3918                                 'wl_user' => $user->getId()
3919                         ),
3920                         __METHOD__
3921                 );
3922                 return $this->mNotificationTimestamp[$uid];
3923         }
3924
3925         /**
3926          * Get the trackback URL for this page
3927          *
3928          * @return String Trackback URL
3929          */
3930         public function trackbackURL() {
3931                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3932
3933                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3934                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3935         }
3936
3937         /**
3938          * Get the trackback RDF for this page
3939          *
3940          * @return String Trackback RDF
3941          */
3942         public function trackbackRDF() {
3943                 $url = htmlspecialchars( $this->getFullURL() );
3944                 $title = htmlspecialchars( $this->getText() );
3945                 $tburl = $this->trackbackURL();
3946
3947                 // Autodiscovery RDF is placed in comments so HTML validator
3948                 // won't barf. This is a rather icky workaround, but seems
3949                 // frequently used by this kind of RDF thingy.
3950                 //
3951                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3952                 return "<!--
3953 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3954                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3955                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3956 <rdf:Description
3957    rdf:about=\"$url\"
3958    dc:identifier=\"$url\"
3959    dc:title=\"$title\"
3960    trackback:ping=\"$tburl\" />
3961 </rdf:RDF>
3962 -->";
3963         }
3964
3965         /**
3966          * Generate strings used for xml 'id' names in monobook tabs
3967          *
3968          * @param $prepend string defaults to 'nstab-'
3969          * @return String XML 'id' name
3970          */
3971         public function getNamespaceKey( $prepend = 'nstab-' ) {
3972                 global $wgContLang;
3973                 // Gets the subject namespace if this title
3974                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3975                 // Checks if cononical namespace name exists for namespace
3976                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3977                         // Uses canonical namespace name
3978                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3979                 } else {
3980                         // Uses text of namespace
3981                         $namespaceKey = $this->getSubjectNsText();
3982                 }
3983                 // Makes namespace key lowercase
3984                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3985                 // Uses main
3986                 if ( $namespaceKey == '' ) {
3987                         $namespaceKey = 'main';
3988                 }
3989                 // Changes file to image for backwards compatibility
3990                 if ( $namespaceKey == 'file' ) {
3991                         $namespaceKey = 'image';
3992                 }
3993                 return $prepend . $namespaceKey;
3994         }
3995
3996         /**
3997          * Returns true if this is a special page.
3998          *
3999          * @return boolean
4000          */
4001         public function isSpecialPage() {
4002                 return $this->getNamespace() == NS_SPECIAL;
4003         }
4004
4005         /**
4006          * Returns true if this title resolves to the named special page
4007          *
4008          * @param $name String The special page name
4009          * @return boolean
4010          */
4011         public function isSpecial( $name ) {
4012                 if ( $this->getNamespace() == NS_SPECIAL ) {
4013                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4014                         if ( $name == $thisName ) {
4015                                 return true;
4016                         }
4017                 }
4018                 return false;
4019         }
4020
4021         /**
4022          * If the Title refers to a special page alias which is not the local default, resolve
4023          * the alias, and localise the name as necessary.  Otherwise, return $this
4024          *
4025          * @return Title
4026          */
4027         public function fixSpecialName() {
4028                 if ( $this->getNamespace() == NS_SPECIAL ) {
4029                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4030                         if ( $canonicalName ) {
4031                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4032                                 if ( $localName != $this->mDbkeyform ) {
4033                                         return Title::makeTitle( NS_SPECIAL, $localName );
4034                                 }
4035                         }
4036                 }
4037                 return $this;
4038         }
4039
4040         /**
4041          * Is this Title in a namespace which contains content?
4042          * In other words, is this a content page, for the purposes of calculating
4043          * statistics, etc?
4044          *
4045          * @return Boolean
4046          */
4047         public function isContentPage() {
4048                 return MWNamespace::isContent( $this->getNamespace() );
4049         }
4050
4051         /**
4052          * Get all extant redirects to this Title
4053          *
4054          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4055          * @return Array of Title redirects to this title
4056          */
4057         public function getRedirectsHere( $ns = null ) {
4058                 $redirs = array();
4059
4060                 $dbr = wfGetDB( DB_SLAVE );
4061                 $where = array(
4062                         'rd_namespace' => $this->getNamespace(),
4063                         'rd_title' => $this->getDBkey(),
4064                         'rd_from = page_id'
4065                 );
4066                 if ( !is_null( $ns ) ) {
4067                         $where['page_namespace'] = $ns;
4068                 }
4069
4070                 $res = $dbr->select(
4071                         array( 'redirect', 'page' ),
4072                         array( 'page_namespace', 'page_title' ),
4073                         $where,
4074                         __METHOD__
4075                 );
4076
4077                 foreach ( $res as $row ) {
4078                         $redirs[] = self::newFromRow( $row );
4079                 }
4080                 return $redirs;
4081         }
4082
4083         /**
4084          * Check if this Title is a valid redirect target
4085          *
4086          * @return Bool
4087          */
4088         public function isValidRedirectTarget() {
4089                 global $wgInvalidRedirectTargets;
4090
4091                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4092                 if ( $this->isSpecial( 'Userlogout' ) ) {
4093                         return false;
4094                 }
4095
4096                 foreach ( $wgInvalidRedirectTargets as $target ) {
4097                         if ( $this->isSpecial( $target ) ) {
4098                                 return false;
4099                         }
4100                 }
4101
4102                 return true;
4103         }
4104
4105         /**
4106          * Get a backlink cache object
4107          *
4108          * @return object BacklinkCache
4109          */
4110         function getBacklinkCache() {
4111                 if ( is_null( $this->mBacklinkCache ) ) {
4112                         $this->mBacklinkCache = new BacklinkCache( $this );
4113                 }
4114                 return $this->mBacklinkCache;
4115         }
4116
4117         /**
4118          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4119          *
4120          * @return Boolean
4121          */
4122         public function canUseNoindex() {
4123                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4124
4125                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4126                         ? $wgContentNamespaces
4127                         : $wgExemptFromUserRobotsControl;
4128
4129                 return !in_array( $this->mNamespace, $bannedNamespaces );
4130
4131         }
4132
4133         /**
4134          * Returns restriction types for the current Title
4135          *
4136          * @return array applicable restriction types
4137          */
4138         public function getRestrictionTypes() {
4139                 if ( $this->getNamespace() == NS_SPECIAL ) {
4140                         return array();
4141                 }
4142
4143                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4144
4145                 if ( $this->getNamespace() != NS_FILE ) {
4146                         # Remove the upload restriction for non-file titles
4147                         $types = array_diff( $types, array( 'upload' ) );
4148                 }
4149
4150                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4151
4152                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4153                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4154
4155                 return $types;
4156         }
4157         /**
4158          * Get a filtered list of all restriction types supported by this wiki.
4159          * @param bool $exists True to get all restriction types that apply to
4160          * titles that do exist, False for all restriction types that apply to
4161          * titles that do not exist
4162          * @return array
4163          */
4164         public static function getFilteredRestrictionTypes( $exists = true ) {
4165                 global $wgRestrictionTypes;
4166                 $types = $wgRestrictionTypes;
4167                 if ( $exists ) {
4168                         # Remove the create restriction for existing titles
4169                         $types = array_diff( $types, array( 'create' ) );
4170                 } else {
4171                         # Only the create and upload restrictions apply to non-existing titles
4172                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4173                 }
4174                 return $types;
4175         }
4176
4177         /**
4178          * Returns the raw sort key to be used for categories, with the specified
4179          * prefix.  This will be fed to Collation::getSortKey() to get a
4180          * binary sortkey that can be used for actual sorting.
4181          *
4182          * @param $prefix string The prefix to be used, specified using
4183          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4184          *   prefix.
4185          * @return string
4186          */
4187         public function getCategorySortkey( $prefix = '' ) {
4188                 $unprefixed = $this->getText();
4189                 if ( $prefix !== '' ) {
4190                         # Separate with a line feed, so the unprefixed part is only used as
4191                         # a tiebreaker when two pages have the exact same prefix.
4192                         # In UCA, tab is the only character that can sort above LF
4193                         # so we strip both of them from the original prefix.
4194                         $prefix = strtr( $prefix, "\n\t", '  ' );
4195                         return "$prefix\n$unprefixed";
4196                 }
4197                 return $unprefixed;
4198         }
4199 }