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 of getTitleProtection
  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 \type{\string} The database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return \type{Title} the new object, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text string  The link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace int The namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title  The new object, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 /**
 142                  * Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 143                  */
 144                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 145
 146                 $t = new Title();
 147                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 148                 $t->mDefaultNamespace = $defaultNamespace;
 149
 150                 static $cachedcount = 0 ;
 151                 if ( $t->secureAndSplit() ) {
 152                         if ( $defaultNamespace == NS_MAIN ) {
 153                                 if ( $cachedcount >= self::CACHE_MAX ) {
 154                                         # Avoid memory leaks on mass operations...
 155                                         Title::$titleCache = array();
 156                                         $cachedcount = 0;
 157                                 }
 158                                 $cachedcount++;
 159                                 Title::$titleCache[$text] =& $t;
 160                         }
 161                         return $t;
 162                 } else {
 163                         $ret = null;
 164                         return $ret;
 165                 }
 166         }
 167
 168         /**
 169          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 170          *
 171          * Example of wrong and broken code:
 172          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Example of right code:
 175          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Create a new Title from URL-encoded text. Ensures that
 178          * the given title's length does not exceed the maximum.
 179          *
 180          * @param $url \type{\string} the title, as might be taken from a URL
 181          * @return \type{Title} the new object, or NULL on an error
 182          */
 183         public static function newFromURL( $url ) {
 184                 global $wgLegalTitleChars;
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id \type{\int} the page_id corresponding to the Title to create
 206          * @param $flags \type{\int} use Title::GAID_FOR_UPDATE to use master
 207          * @return \type{Title} the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 212                 if ( $row !== false ) {
 213                         $title = Title::newFromRow( $row );
 214                 } else {
 215                         $title = null;
 216                 }
 217                 return $title;
 218         }
 219
 220         /**
 221          * Make an array of titles from an array of IDs
 222          *
 223          * @param $ids \type{\arrayof{\int}} Array of IDs
 224          * @return \type{\arrayof{Title}} Array of Titles
 225          */
 226         public static function newFromIDs( $ids ) {
 227                 if ( !count( $ids ) ) {
 228                         return array();
 229                 }
 230                 $dbr = wfGetDB( DB_SLAVE );
 231
 232                 $res = $dbr->select(
 233                         'page',
 234                         array(
 235                                 'page_namespace', 'page_title', 'page_id',
 236                                 'page_len', 'page_is_redirect', 'page_latest',
 237                         ),
 238                         array( 'page_id' => $ids ),
 239                         __METHOD__
 240                 );
 241
 242                 $titles = array();
 243                 foreach ( $res as $row ) {
 244                         $titles[] = Title::newFromRow( $row );
 245                 }
 246                 return $titles;
 247         }
 248
 249         /**
 250          * Make a Title object from a DB row
 251          *
 252          * @param $row \type{Row} (needs at least page_title,page_namespace)
 253          * @return \type{Title} corresponding Title
 254          */
 255         public static function newFromRow( $row ) {
 256                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 257
 258                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 259                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 260                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 261                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 262
 263                 return $t;
 264         }
 265
 266         /**
 267          * Create a new Title from a namespace index and a DB key.
 268          * It's assumed that $ns and $title are *valid*, for instance when
 269          * they came directly from the database or a special page name.
 270          * For convenience, spaces are converted to underscores so that
 271          * eg user_text fields can be used directly.
 272          *
 273          * @param $ns \type{\int} the namespace of the article
 274          * @param $title \type{\string} the unprefixed database key form
 275          * @param $fragment \type{\string} The link fragment (after the "#")
 276          * @param $interwiki \type{\string} The interwiki prefix
 277          * @return \type{Title} the new object
 278          */
 279         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 280                 $t = new Title();
 281                 $t->mInterwiki = $interwiki;
 282                 $t->mFragment = $fragment;
 283                 $t->mNamespace = $ns = intval( $ns );
 284                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 285                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 286                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 287                 $t->mTextform = str_replace( '_', ' ', $title );
 288                 return $t;
 289         }
 290
 291         /**
 292          * Create a new Title from a namespace index and a DB key.
 293          * The parameters will be checked for validity, which is a bit slower
 294          * than makeTitle() but safer for user-provided data.
 295          *
 296          * @param $ns \type{\int} the namespace of the article
 297          * @param $title \type{\string} the database key form
 298          * @param $fragment \type{\string} The link fragment (after the "#")
 299          * @param $interwiki \type{\string} The interwiki prefix
 300          * @return \type{Title} the new object, or NULL on an error
 301          */
 302         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 303                 $t = new Title();
 304                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 305                 if ( $t->secureAndSplit() ) {
 306                         return $t;
 307                 } else {
 308                         return null;
 309                 }
 310         }
 311
 312         /**
 313          * Create a new Title for the Main Page
 314          *
 315          * @return \type{Title} the new object
 316          */
 317         public static function newMainPage() {
 318                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 319                 // Don't give fatal errors if the message is broken
 320                 if ( !$title ) {
 321                         $title = Title::newFromText( 'Main Page' );
 322                 }
 323                 return $title;
 324         }
 325
 326         /**
 327          * Extract a redirect destination from a string and return the
 328          * Title, or null if the text doesn't contain a valid redirect
 329          * This will only return the very next target, useful for
 330          * the redirect table and other checks that don't need full recursion
 331          *
 332          * @param $text String: Text with possible redirect
 333          * @return Title: The corresponding Title
 334          */
 335         public static function newFromRedirect( $text ) {
 336                 return self::newFromRedirectInternal( $text );
 337         }
 338
 339         /**
 340          * Extract a redirect destination from a string and return the
 341          * Title, or null if the text doesn't contain a valid redirect
 342          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 343          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 344          *
 345          * @param $text \type{\string} Text with possible redirect
 346          * @return \type{Title} The corresponding Title
 347          */
 348         public static function newFromRedirectRecurse( $text ) {
 349                 $titles = self::newFromRedirectArray( $text );
 350                 return $titles ? array_pop( $titles ) : null;
 351         }
 352
 353         /**
 354          * Extract a redirect destination from a string and return an
 355          * array of Titles, or null if the text doesn't contain a valid redirect
 356          * The last element in the array is the final destination after all redirects
 357          * have been resolved (up to $wgMaxRedirects times)
 358          *
 359          * @param $text \type{\string} Text with possible redirect
 360          * @return \type{\array} Array of Titles, with the destination last
 361          */
 362         public static function newFromRedirectArray( $text ) {
 363                 global $wgMaxRedirects;
 364                 // are redirects disabled?
 365                 if ( $wgMaxRedirects < 1 ) {
 366                         return null;
 367                 }
 368                 $title = self::newFromRedirectInternal( $text );
 369                 if ( is_null( $title ) ) {
 370                         return null;
 371                 }
 372                 // recursive check to follow double redirects
 373                 $recurse = $wgMaxRedirects;
 374                 $titles = array( $title );
 375                 while ( --$recurse > 0 ) {
 376                         if ( $title->isRedirect() ) {
 377                                 $article = new Article( $title, 0 );
 378                                 $newtitle = $article->getRedirectTarget();
 379                         } else {
 380                                 break;
 381                         }
 382                         // Redirects to some special pages are not permitted
 383                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 384                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 385                                 $title = $newtitle;
 386                                 $titles[] = $newtitle;
 387                         } else {
 388                                 break;
 389                         }
 390                 }
 391                 return $titles;
 392         }
 393
 394         /**
 395          * Really extract the redirect destination
 396          * Do not call this function directly, use one of the newFromRedirect* functions above
 397          *
 398          * @param $text \type{\string} Text with possible redirect
 399          * @return \type{Title} The corresponding Title
 400          */
 401         protected static function newFromRedirectInternal( $text ) {
 402                 $redir = MagicWord::get( 'redirect' );
 403                 $text = trim( $text );
 404                 if ( $redir->matchStartAndRemove( $text ) ) {
 405                         // Extract the first link and see if it's usable
 406                         // Ensure that it really does come directly after #REDIRECT
 407                         // Some older redirects included a colon, so don't freak about that!
 408                         $m = array();
 409                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 410                                 // Strip preceding colon used to "escape" categories, etc.
 411                                 // and URL-decode links
 412                                 if ( strpos( $m[1], '%' ) !== false ) {
 413                                         // Match behavior of inline link parsing here;
 414                                         // don't interpret + as " " most of the time!
 415                                         // It might be safe to just use rawurldecode instead, though.
 416                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 417                                 }
 418                                 $title = Title::newFromText( $m[1] );
 419                                 // If the title is a redirect to bad special pages or is invalid, return null
 420                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 421                                         return null;
 422                                 }
 423                                 return $title;
 424                         }
 425                 }
 426                 return null;
 427         }
 428
 429 # ----------------------------------------------------------------------------
 430 #       Static functions
 431 # ----------------------------------------------------------------------------
 432
 433         /**
 434          * Get the prefixed DB key associated with an ID
 435          *
 436          * @param $id \type{\int} the page_id of the article
 437          * @return \type{Title} an object representing the article, or NULL
 438          *  if no such article was found
 439          */
 440         public static function nameOf( $id ) {
 441                 $dbr = wfGetDB( DB_SLAVE );
 442
 443                 $s = $dbr->selectRow(
 444                         'page',
 445                         array( 'page_namespace', 'page_title' ),
 446                         array( 'page_id' => $id ),
 447                         __METHOD__
 448                 );
 449                 if ( $s === false ) {
 450                         return null;
 451                 }
 452
 453                 $n = self::makeName( $s->page_namespace, $s->page_title );
 454                 return $n;
 455         }
 456
 457         /**
 458          * Get a regex character class describing the legal characters in a link
 459          *
 460          * @return \type{\string} the list of characters, not delimited
 461          */
 462         public static function legalChars() {
 463                 global $wgLegalTitleChars;
 464                 return $wgLegalTitleChars;
 465         }
 466
 467         /**
 468          * Get a string representation of a title suitable for
 469          * including in a search index
 470          *
 471          * @param $ns \type{\int} a namespace index
 472          * @param $title \type{\string} text-form main part
 473          * @return \type{\string} a stripped-down title string ready for the
 474          *  search index
 475          */
 476         public static function indexTitle( $ns, $title ) {
 477                 global $wgContLang;
 478
 479                 $lc = SearchEngine::legalSearchChars() . '&#;';
 480                 $t = $wgContLang->normalizeForSearch( $title );
 481                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 482                 $t = $wgContLang->lc( $t );
 483
 484                 # Handle 's, s'
 485                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 486                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 487
 488                 $t = preg_replace( "/\\s+/", ' ', $t );
 489
 490                 if ( $ns == NS_FILE ) {
 491                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 492                 }
 493                 return trim( $t );
 494         }
 495
 496         /**
 497          * Make a prefixed DB key from a DB key and a namespace index
 498          *
 499          * @param $ns \type{\int} numerical representation of the namespace
 500          * @param $title \type{\string} the DB key form the title
 501          * @param $fragment \type{\string} The link fragment (after the "#")
 502          * @param $interwiki \type{\string} The interwiki prefix
 503          * @return \type{\string} the prefixed form of the title
 504          */
 505         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 506                 global $wgContLang;
 507
 508                 $namespace = $wgContLang->getNsText( $ns );
 509                 $name = $namespace == '' ? $title : "$namespace:$title";
 510                 if ( strval( $interwiki ) != '' ) {
 511                         $name = "$interwiki:$name";
 512                 }
 513                 if ( strval( $fragment ) != '' ) {
 514                         $name .= '#' . $fragment;
 515                 }
 516                 return $name;
 517         }
 518
 519         /**
 520          * Determine whether the object refers to a page within
 521          * this project.
 522          *
 523          * @return \type{\bool} TRUE if this is an in-project interwiki link
 524          *      or a wikilink, FALSE otherwise
 525          */
 526         public function isLocal() {
 527                 if ( $this->mInterwiki != '' ) {
 528                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 529                 } else {
 530                         return true;
 531                 }
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project and is transcludable.
 537          *
 538          * @return \type{\bool} TRUE if this is transcludable
 539          */
 540         public function isTrans() {
 541                 if ( $this->mInterwiki == '' ) {
 542                         return false;
 543                 }
 544
 545                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 546         }
 547
 548         /**
 549          * Returns the DB name of the distant wiki
 550          * which owns the object.
 551          *
 552          * @return \type{\string} the DB name
 553          */
 554         public function getTransWikiID() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 560         }
 561
 562         /**
 563          * Escape a text fragment, say from a link, for a URL
 564          *
 565          * @param $fragment string containing a URL or link fragment (after the "#")
 566          * @return String: escaped string
 567          */
 568         static function escapeFragmentForURL( $fragment ) {
 569                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 570                 # fragments appear not to work in IE (at least up to 7) or in at least
 571                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 572                 # to care if they aren't encoded.
 573                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 574         }
 575
 576 # ----------------------------------------------------------------------------
 577 #       Other stuff
 578 # ----------------------------------------------------------------------------
 579
 580         /** Simple accessors */
 581         /**
 582          * Get the text form (spaces not underscores) of the main part
 583          *
 584          * @return \type{\string} Main part of the title
 585          */
 586         public function getText() { return $this->mTextform; }
 587
 588         /**
 589          * Get the URL-encoded form of the main part
 590          *
 591          * @return \type{\string} Main part of the title, URL-encoded
 592          */
 593         public function getPartialURL() { return $this->mUrlform; }
 594
 595         /**
 596          * Get the main part with underscores
 597          *
 598          * @return String: Main part of the title, with underscores
 599          */
 600         public function getDBkey() { return $this->mDbkeyform; }
 601
 602         /**
 603          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 604          *
 605          * @return Integer: Namespace index
 606          */
 607         public function getNamespace() { return $this->mNamespace; }
 608
 609         /**
 610          * Get the namespace text
 611          *
 612          * @return String: Namespace text
 613          */
 614         public function getNsText() {
 615                 global $wgContLang;
 616
 617                 if ( $this->mInterwiki != '' ) {
 618                         // This probably shouldn't even happen. ohh man, oh yuck.
 619                         // But for interwiki transclusion it sometimes does.
 620                         // Shit. Shit shit shit.
 621                         //
 622                         // Use the canonical namespaces if possible to try to
 623                         // resolve a foreign namespace.
 624                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 625                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\int} Default namespace index
 699          */
 700         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 701
 702         /**
 703          * Get title for search index
 704          *
 705          * @return \type{\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 \type{\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 \type{\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 \type{\string} the prefixed title, with spaces and
 744          *  the fragment, including '#'
 745          */
 746         public function getFullText() {
 747                 $text = $this->getPrefixedText();
 748                 if ( $this->mFragment != '' ) {
 749                         $text .= '#' . $this->mFragment;
 750                 }
 751                 return $text;
 752         }
 753
 754         /**
 755          * Get the base name, i.e. the leftmost parts before the /
 756          *
 757          * @return \type{\string} Base name
 758          */
 759         public function getBaseText() {
 760                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 761                         return $this->getText();
 762                 }
 763
 764                 $parts = explode( '/', $this->getText() );
 765                 # Don't discard the real title if there's no subpage involved
 766                 if ( count( $parts ) > 1 ) {
 767                         unset( $parts[count( $parts ) - 1] );
 768                 }
 769                 return implode( '/', $parts );
 770         }
 771
 772         /**
 773          * Get the lowest-level subpage name, i.e. the rightmost part after /
 774          *
 775          * @return \type{\string} Subpage name
 776          */
 777         public function getSubpageText() {
 778                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 779                         return( $this->mTextform );
 780                 }
 781                 $parts = explode( '/', $this->mTextform );
 782                 return( $parts[count( $parts ) - 1] );
 783         }
 784
 785         /**
 786          * Get a URL-encoded form of the subpage text
 787          *
 788          * @return \type{\string} URL-encoded subpage name
 789          */
 790         public function getSubpageUrlForm() {
 791                 $text = $this->getSubpageText();
 792                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 793                 return( $text );
 794         }
 795
 796         /**
 797          * Get a URL-encoded title (not an actual URL) including interwiki
 798          *
 799          * @return \type{\string} the URL-encoded form
 800          */
 801         public function getPrefixedURL() {
 802                 $s = $this->prefix( $this->mDbkeyform );
 803                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 804                 return $s;
 805         }
 806
 807         /**
 808          * Get a real URL referring to this title, with interwiki link and
 809          * fragment
 810          *
 811          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 812          *   links. Can be specified as an associative array as well, e.g.,
 813          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 814          * @param $variant \type{\string} language variant of url (for sr, zh..)
 815          * @return \type{\string} the URL
 816          */
 817         public function getFullURL( $query = '', $variant = false ) {
 818                 global $wgServer, $wgRequest;
 819
 820                 if ( is_array( $query ) ) {
 821                         $query = wfArrayToCGI( $query );
 822                 }
 823
 824                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 825                 if ( !$interwiki ) {
 826                         $url = $this->getLocalURL( $query, $variant );
 827
 828                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 829                         // Correct fix would be to move the prepending elsewhere.
 830                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 831                                 $url = $wgServer . $url;
 832                         }
 833                 } else {
 834                         $baseUrl = $interwiki->getURL();
 835
 836                         $namespace = wfUrlencode( $this->getNsText() );
 837                         if ( $namespace != '' ) {
 838                                 # Can this actually happen? Interwikis shouldn't be parsed.
 839                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 840                                 $namespace .= ':';
 841                         }
 842                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 843                         $url = wfAppendQuery( $url, $query );
 844                 }
 845
 846                 # Finally, add the fragment.
 847                 $url .= $this->getFragmentForURL();
 848
 849                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 850                 return $url;
 851         }
 852
 853         /**
 854          * Get a URL with no fragment or server name.  If this page is generated
 855          * with action=render, $wgServer is prepended.
 856          *
 857          * @param $query Mixed: an optional query string; if not specified,
 858          *   $wgArticlePath will be used.  Can be specified as an associative array
 859          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 860          *   URL-escaped).
 861          * @param $variant \type{\string} language variant of url (for sr, zh..)
 862          * @return \type{\string} the URL
 863          */
 864         public function getLocalURL( $query = '', $variant = false ) {
 865                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 866                 global $wgVariantArticlePath, $wgContLang;
 867
 868                 if ( is_array( $query ) ) {
 869                         $query = wfArrayToCGI( $query );
 870                 }
 871
 872                 if ( $this->isExternal() ) {
 873                         $url = $this->getFullURL();
 874                         if ( $query ) {
 875                                 // This is currently only used for edit section links in the
 876                                 // context of interwiki transclusion. In theory we should
 877                                 // append the query to the end of any existing query string,
 878                                 // but interwiki transclusion is already broken in that case.
 879                                 $url .= "?$query";
 880                         }
 881                 } else {
 882                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 883                         if ( $query == '' ) {
 884                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 885                                         if ( !$wgVariantArticlePath ) {
 886                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 887                                         } else {
 888                                                 $variantArticlePath = $wgVariantArticlePath;
 889                                         }
 890                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 891                                         $url = str_replace( '$1', $dbkey, $url  );
 892                                 } else {
 893                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 894                                 }
 895                         } else {
 896                                 global $wgActionPaths;
 897                                 $url = false;
 898                                 $matches = array();
 899                                 if ( !empty( $wgActionPaths ) &&
 900                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 901                                 {
 902                                         $action = urldecode( $matches[2] );
 903                                         if ( isset( $wgActionPaths[$action] ) ) {
 904                                                 $query = $matches[1];
 905                                                 if ( isset( $matches[4] ) ) {
 906                                                         $query .= $matches[4];
 907                                                 }
 908                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 909                                                 if ( $query != '' ) {
 910                                                         $url = wfAppendQuery( $url, $query );
 911                                                 }
 912                                         }
 913                                 }
 914                                 if ( $url === false ) {
 915                                         if ( $query == '-' ) {
 916                                                 $query = '';
 917                                         }
 918                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 919                                 }
 920                         }
 921
 922                         // FIXME: this causes breakage in various places when we
 923                         // actually expected a local URL and end up with dupe prefixes.
 924                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 925                                 $url = $wgServer . $url;
 926                         }
 927                 }
 928                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 929                 return $url;
 930         }
 931
 932         /**
 933          * Get a URL that's the simplest URL that will be valid to link, locally,
 934          * to the current Title.  It includes the fragment, but does not include
 935          * the server unless action=render is used (or the link is external).  If
 936          * there's a fragment but the prefixed text is empty, we just return a link
 937          * to the fragment.
 938          *
 939          * The result obviously should not be URL-escaped, but does need to be
 940          * HTML-escaped if it's being output in HTML.
 941          *
 942          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 943          *   query string.  Keys and values will be escaped.
 944          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 945          *   for external links.  Default is "false" (same variant as current page,
 946          *   for anonymous users).
 947          * @return \type{\string} the URL
 948          */
 949         public function getLinkUrl( $query = array(), $variant = false ) {
 950                 wfProfileIn( __METHOD__ );
 951                 if ( $this->isExternal() ) {
 952                         $ret = $this->getFullURL( $query );
 953                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 954                         $ret = $this->getFragmentForURL();
 955                 } else {
 956                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 957                 }
 958                 wfProfileOut( __METHOD__ );
 959                 return $ret;
 960         }
 961
 962         /**
 963          * Get an HTML-escaped version of the URL form, suitable for
 964          * using in a link, without a server name or fragment
 965          *
 966          * @param $query \type{\string} an optional query string
 967          * @return \type{\string} the URL
 968          */
 969         public function escapeLocalURL( $query = '' ) {
 970                 return htmlspecialchars( $this->getLocalURL( $query ) );
 971         }
 972
 973         /**
 974          * Get an HTML-escaped version of the URL form, suitable for
 975          * using in a link, including the server name and fragment
 976          *
 977          * @param $query \type{\string} an optional query string
 978          * @return \type{\string} the URL
 979          */
 980         public function escapeFullURL( $query = '' ) {
 981                 return htmlspecialchars( $this->getFullURL( $query ) );
 982         }
 983
 984         /**
 985          * Get the URL form for an internal link.
 986          * - Used in various Squid-related code, in case we have a different
 987          * internal hostname for the server from the exposed one.
 988          *
 989          * @param $query \type{\string} an optional query string
 990          * @param $variant \type{\string} language variant of url (for sr, zh..)
 991          * @return \type{\string} the URL
 992          */
 993         public function getInternalURL( $query = '', $variant = false ) {
 994                 global $wgInternalServer;
 995                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 996                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 997                 return $url;
 998         }
 999
1000         /**
1001          * Get the edit URL for this Title
1002          *
1003          * @return \type{\string} the URL, or a null string if this is an
1004          *  interwiki link
1005          */
1006         public function getEditURL() {
1007                 if ( $this->mInterwiki != '' ) {
1008                         return '';
1009                 }
1010                 $s = $this->getLocalURL( 'action=edit' );
1011
1012                 return $s;
1013         }
1014
1015         /**
1016          * Get the HTML-escaped displayable text form.
1017          * Used for the title field in <a> tags.
1018          *
1019          * @return \type{\string} the text, including any prefixes
1020          */
1021         public function getEscapedText() {
1022                 return htmlspecialchars( $this->getPrefixedText() );
1023         }
1024
1025         /**
1026          * Is this Title interwiki?
1027          *
1028          * @return \type{\bool}
1029          */
1030         public function isExternal() {
1031                 return ( $this->mInterwiki != '' );
1032         }
1033
1034         /**
1035          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1036          *
1037          * @param $action \type{\string} Action to check (default: edit)
1038          * @return \type{\bool}
1039          */
1040         public function isSemiProtected( $action = 'edit' ) {
1041                 if ( $this->exists() ) {
1042                         $restrictions = $this->getRestrictions( $action );
1043                         if ( count( $restrictions ) > 0 ) {
1044                                 foreach ( $restrictions as $restriction ) {
1045                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1046                                                 return false;
1047                                         }
1048                                 }
1049                         } else {
1050                                 # Not protected
1051                                 return false;
1052                         }
1053                         return true;
1054                 } else {
1055                         # If it doesn't exist, it can't be protected
1056                         return false;
1057                 }
1058         }
1059
1060         /**
1061          * Does the title correspond to a protected article?
1062          *
1063          * @param $action \type{\string} the action the page is protected from,
1064          * by default checks all actions.
1065          * @return \type{\bool}
1066          */
1067         public function isProtected( $action = '' ) {
1068                 global $wgRestrictionLevels;
1069
1070                 $restrictionTypes = $this->getRestrictionTypes();
1071
1072                 # Special pages have inherent protection
1073                 if( $this->getNamespace() == NS_SPECIAL ) {
1074                         return true;
1075                 }
1076
1077                 # Check regular protection levels
1078                 foreach ( $restrictionTypes as $type ) {
1079                         if ( $action == $type || $action == '' ) {
1080                                 $r = $this->getRestrictions( $type );
1081                                 foreach ( $wgRestrictionLevels as $level ) {
1082                                         if ( in_array( $level, $r ) && $level != '' ) {
1083                                                 return true;
1084                                         }
1085                                 }
1086                         }
1087                 }
1088
1089                 return false;
1090         }
1091
1092         /**
1093          * Is this a conversion table for the LanguageConverter?
1094          *
1095          * @return \type{\bool}
1096          */
1097         public function isConversionTable() {
1098                 if(
1099                         $this->getNamespace() == NS_MEDIAWIKI &&
1100                         strpos( $this->getText(), 'Conversiontable' ) !== false
1101                 )
1102                 {
1103                         return true;
1104                 }
1105
1106                 return false;
1107         }
1108
1109         /**
1110          * Is $wgUser watching this page?
1111          *
1112          * @return \type{\bool}
1113          */
1114         public function userIsWatching() {
1115                 global $wgUser;
1116
1117                 if ( is_null( $this->mWatched ) ) {
1118                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1119                                 $this->mWatched = false;
1120                         } else {
1121                                 $this->mWatched = $wgUser->isWatched( $this );
1122                         }
1123                 }
1124                 return $this->mWatched;
1125         }
1126
1127         /**
1128          * Can $wgUser perform $action on this page?
1129          * This skips potentially expensive cascading permission checks
1130          * as well as avoids expensive error formatting
1131          *
1132          * Suitable for use for nonessential UI controls in common cases, but
1133          * _not_ for functional access control.
1134          *
1135          * May provide false positives, but should never provide a false negative.
1136          *
1137          * @param $action \type{\string} action that permission needs to be checked for
1138          * @return \type{\bool}
1139          */
1140         public function quickUserCan( $action ) {
1141                 return $this->userCan( $action, false );
1142         }
1143
1144         /**
1145          * Determines if $user is unable to edit this page because it has been protected
1146          * by $wgNamespaceProtection.
1147          *
1148          * @param $user User object, $wgUser will be used if not passed
1149          * @return \type{\bool}
1150          */
1151         public function isNamespaceProtected( User $user = null ) {
1152                 global $wgNamespaceProtection;
1153
1154                 if ( $user === null ) {
1155                         global $wgUser;
1156                         $user = $wgUser;
1157                 }
1158
1159                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1160                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1161                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1162                                         return true;
1163                                 }
1164                         }
1165                 }
1166                 return false;
1167         }
1168
1169         /**
1170          * Can $wgUser perform $action on this page?
1171          *
1172          * @param $action \type{\string} action that permission needs to be checked for
1173          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1174          * @return \type{\bool}
1175          */
1176         public function userCan( $action, $doExpensiveQueries = true ) {
1177                 global $wgUser;
1178                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1179         }
1180
1181         /**
1182          * Can $user perform $action on this page?
1183          *
1184          * FIXME: This *does not* check throttles (User::pingLimiter()).
1185          *
1186          * @param $action \type{\string}action that permission needs to be checked for
1187          * @param $user \type{User} user to check
1188          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1189          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1190          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1191          */
1192         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1193                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1194
1195                 // Remove the errors being ignored.
1196                 foreach ( $errors as $index => $error ) {
1197                         $error_key = is_array( $error ) ? $error[0] : $error;
1198
1199                         if ( in_array( $error_key, $ignoreErrors ) ) {
1200                                 unset( $errors[$index] );
1201                         }
1202                 }
1203
1204                 return $errors;
1205         }
1206
1207         /**
1208          * Permissions checks that fail most often, and which are easiest to test.
1209          *
1210          * @param $action String the action to check
1211          * @param $user User user to check
1212          * @param $errors Array list of current errors
1213          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1214          * @param $short Boolean short circuit on first error
1215          *
1216          * @return Array list of errors
1217          */
1218         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1219                 if ( $action == 'create' ) {
1220                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1221                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1222                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1223                         }
1224                 } elseif ( $action == 'move' ) {
1225                         if ( !$user->isAllowed( 'move-rootuserpages' )
1226                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1227                                 // Show user page-specific message only if the user can move other pages
1228                                 $errors[] = array( 'cant-move-user-page' );
1229                         }
1230
1231                         // Check if user is allowed to move files if it's a file
1232                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1233                                 $errors[] = array( 'movenotallowedfile' );
1234                         }
1235
1236                         if ( !$user->isAllowed( 'move' ) ) {
1237                                 // User can't move anything
1238                                 global $wgGroupPermissions;
1239                                 $userCanMove = false;
1240                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1241                                         $userCanMove = $wgGroupPermissions['user']['move'];
1242                                 }
1243                                 $autoconfirmedCanMove = false;
1244                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1245                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1246                                 }
1247                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1248                                         // custom message if logged-in users without any special rights can move
1249                                         $errors[] = array( 'movenologintext' );
1250                                 } else {
1251                                         $errors[] = array( 'movenotallowed' );
1252                                 }
1253                         }
1254                 } elseif ( $action == 'move-target' ) {
1255                         if ( !$user->isAllowed( 'move' ) ) {
1256                                 // User can't move anything
1257                                 $errors[] = array( 'movenotallowed' );
1258                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1259                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1260                                 // Show user page-specific message only if the user can move other pages
1261                                 $errors[] = array( 'cant-move-to-user-page' );
1262                         }
1263                 } elseif ( !$user->isAllowed( $action ) ) {
1264                         // We avoid expensive display logic for quickUserCan's and such
1265                         $groups = false;
1266                         if ( !$short ) {
1267                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1268                                         User::getGroupsWithPermission( $action ) );
1269                         }
1270
1271                         if ( $groups ) {
1272                                 global $wgLang;
1273                                 $return = array(
1274                                         'badaccess-groups',
1275                                         $wgLang->commaList( $groups ),
1276                                         count( $groups )
1277                                 );
1278                         } else {
1279                                 $return = array( 'badaccess-group0' );
1280                         }
1281                         $errors[] = $return;
1282                 }
1283
1284                 return $errors;
1285         }
1286
1287         /**
1288          * Add the resulting error code to the errors array
1289          *
1290          * @param $errors Array list of current errors
1291          * @param $result Mixed result of errors
1292          *
1293          * @return Array list of errors
1294          */
1295         private function resultToError( $errors, $result ) {
1296                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1297                         // A single array representing an error
1298                         $errors[] = $result;
1299                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1300                         // A nested array representing multiple errors
1301                         $errors = array_merge( $errors, $result );
1302                 } else if ( $result !== '' && is_string( $result ) ) {
1303                         // A string representing a message-id
1304                         $errors[] = array( $result );
1305                 } else if ( $result === false ) {
1306                         // a generic "We don't want them to do that"
1307                         $errors[] = array( 'badaccess-group0' );
1308                 }
1309                 return $errors;
1310         }
1311
1312         /**
1313          * Check various permission hooks
1314          *
1315          * @param $action String the action to check
1316          * @param $user User user to check
1317          * @param $errors Array list of current errors
1318          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1319          * @param $short Boolean short circuit on first error
1320          *
1321          * @return Array list of errors
1322          */
1323         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1324                 // Use getUserPermissionsErrors instead
1325                 $result = '';
1326                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1327                         return $result ? array() : array( array( 'badaccess-group0' ) );
1328                 }
1329                 // Check getUserPermissionsErrors hook
1330                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1331                         $errors = $this->resultToError( $errors, $result );
1332                 }
1333                 // Check getUserPermissionsErrorsExpensive hook
1334                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1335                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1336                         $errors = $this->resultToError( $errors, $result );
1337                 }
1338
1339                 return $errors;
1340         }
1341
1342         /**
1343          * Check permissions on special pages & namespaces
1344          *
1345          * @param $action String the action to check
1346          * @param $user User user to check
1347          * @param $errors Array list of current errors
1348          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1349          * @param $short Boolean short circuit on first error
1350          *
1351          * @return Array list of errors
1352          */
1353         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1354                 # Only 'createaccount' and 'execute' can be performed on
1355                 # special pages, which don't actually exist in the DB.
1356                 $specialOKActions = array( 'createaccount', 'execute' );
1357                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1358                         $errors[] = array( 'ns-specialprotected' );
1359                 }
1360
1361                 # Check $wgNamespaceProtection for restricted namespaces
1362                 if ( $this->isNamespaceProtected( $user ) ) {
1363                         $ns = $this->mNamespace == NS_MAIN ?
1364                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1365                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1366                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1367                 }
1368
1369                 return $errors;
1370         }
1371
1372         /**
1373          * Check CSS/JS sub-page permissions
1374          *
1375          * @param $action String the action to check
1376          * @param $user User user to check
1377          * @param $errors Array list of current errors
1378          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1379          * @param $short Boolean short circuit on first error
1380          *
1381          * @return Array list of errors
1382          */
1383         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1384                 # Protect css/js subpages of user pages
1385                 # XXX: this might be better using restrictions
1386                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1387                 #      and $this->userCanEditJsSubpage() from working
1388                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1389                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1390                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1391                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1392                                 $errors[] = array( 'customcssjsprotected' );
1393                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1394                                 $errors[] = array( 'customcssjsprotected' );
1395                         }
1396                 }
1397
1398                 return $errors;
1399         }
1400
1401         /**
1402          * Check against page_restrictions table requirements on this
1403          * page. The user must possess all required rights for this
1404          * action.
1405          *
1406          * @param $action String the action to check
1407          * @param $user User user to check
1408          * @param $errors Array list of current errors
1409          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1410          * @param $short Boolean short circuit on first error
1411          *
1412          * @return Array list of errors
1413          */
1414         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1415                 foreach ( $this->getRestrictions( $action ) as $right ) {
1416                         // Backwards compatibility, rewrite sysop -> protect
1417                         if ( $right == 'sysop' ) {
1418                                 $right = 'protect';
1419                         }
1420                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1421                                 // Users with 'editprotected' permission can edit protected pages
1422                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1423                                         // Users with 'editprotected' permission cannot edit protected pages
1424                                         // with cascading option turned on.
1425                                         if ( $this->mCascadeRestriction ) {
1426                                                 $errors[] = array( 'protectedpagetext', $right );
1427                                         }
1428                                 } else {
1429                                         $errors[] = array( 'protectedpagetext', $right );
1430                                 }
1431                         }
1432                 }
1433
1434                 return $errors;
1435         }
1436
1437         /**
1438          * Check restrictions on cascading pages.
1439          *
1440          * @param $action String the action to check
1441          * @param $user User user to check
1442          * @param $errors Array list of current errors
1443          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1444          * @param $short Boolean short circuit on first error
1445          *
1446          * @return Array list of errors
1447          */
1448         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1449                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1450                         # We /could/ use the protection level on the source page, but it's
1451                         # fairly ugly as we have to establish a precedence hierarchy for pages
1452                         # included by multiple cascade-protected pages. So just restrict
1453                         # it to people with 'protect' permission, as they could remove the
1454                         # protection anyway.
1455                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1456                         # Cascading protection depends on more than this page...
1457                         # Several cascading protected pages may include this page...
1458                         # Check each cascading level
1459                         # This is only for protection restrictions, not for all actions
1460                         if ( isset( $restrictions[$action] ) ) {
1461                                 foreach ( $restrictions[$action] as $right ) {
1462                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1463                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1464                                                 $pages = '';
1465                                                 foreach ( $cascadingSources as $page )
1466                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1467                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1468                                         }
1469                                 }
1470                         }
1471                 }
1472
1473                 return $errors;
1474         }
1475
1476         /**
1477          * Check action permissions not already checked in checkQuickPermissions
1478          *
1479          * @param $action String the action to check
1480          * @param $user User user to check
1481          * @param $errors Array list of current errors
1482          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1483          * @param $short Boolean short circuit on first error
1484          *
1485          * @return Array list of errors
1486          */
1487         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1488                 if ( $action == 'protect' ) {
1489                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1490                                 // If they can't edit, they shouldn't protect.
1491                                 $errors[] = array( 'protect-cantedit' );
1492                         }
1493                 } elseif ( $action == 'create' ) {
1494                         $title_protection = $this->getTitleProtection();
1495                         if( $title_protection ) {
1496                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1497                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1498                                 }
1499                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1500                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1501                                 }
1502                         }
1503                 } elseif ( $action == 'move' ) {
1504                         // Check for immobile pages
1505                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1506                                 // Specific message for this case
1507                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1508                         } elseif ( !$this->isMovable() ) {
1509                                 // Less specific message for rarer cases
1510                                 $errors[] = array( 'immobile-page' );
1511                         }
1512                 } elseif ( $action == 'move-target' ) {
1513                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1514                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1515                         } elseif ( !$this->isMovable() ) {
1516                                 $errors[] = array( 'immobile-target-page' );
1517                         }
1518                 }
1519                 return $errors;
1520         }
1521
1522         /**
1523          * Check that the user isn't blocked from editting.
1524          *
1525          * @param $action String the action to check
1526          * @param $user User user to check
1527          * @param $errors Array list of current errors
1528          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1529          * @param $short Boolean short circuit on first error
1530          *
1531          * @return Array list of errors
1532          */
1533         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1534                 if( $short && count( $errors ) > 0 ) {
1535                         return $errors;
1536                 }
1537
1538                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1539
1540                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1541                         $errors[] = array( 'confirmedittext' );
1542                 }
1543
1544                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1545                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1546                         $block = $user->mBlock;
1547
1548                         // This is from OutputPage::blockedPage
1549                         // Copied at r23888 by werdna
1550
1551                         $id = $user->blockedBy();
1552                         $reason = $user->blockedFor();
1553                         if ( $reason == '' ) {
1554                                 $reason = wfMsg( 'blockednoreason' );
1555                         }
1556                         $ip = wfGetIP();
1557
1558                         if ( is_numeric( $id ) ) {
1559                                 $name = User::whoIs( $id );
1560                         } else {
1561                                 $name = $id;
1562                         }
1563
1564                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1565                         $blockid = $block->mId;
1566                         $blockExpiry = $user->mBlock->mExpiry;
1567                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1568                         if ( $blockExpiry == 'infinity' ) {
1569                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1570                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1571
1572                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1573                                         if ( !strpos( $option, ':' ) )
1574                                                 continue;
1575
1576                                         list( $show, $value ) = explode( ':', $option );
1577
1578                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1579                                                 $blockExpiry = $show;
1580                                                 break;
1581                                         }
1582                                 }
1583                         } else {
1584                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1585                         }
1586
1587                         $intended = $user->mBlock->mAddress;
1588
1589                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1590                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1591                 }
1592
1593                 return $errors;
1594         }
1595
1596         /**
1597          * Can $user perform $action on this page? This is an internal function,
1598          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1599          * checks on wfReadOnly() and blocks)
1600          *
1601          * @param $action \type{\string} action that permission needs to be checked for
1602          * @param $user \type{User} user to check
1603          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1604          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1605          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1606          */
1607         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1608                 wfProfileIn( __METHOD__ );
1609
1610                 $errors = array();
1611                 $checks = array(
1612                         'checkQuickPermissions',
1613                         'checkPermissionHooks',
1614                         'checkSpecialsAndNSPermissions',
1615                         'checkCSSandJSPermissions',
1616                         'checkPageRestrictions',
1617                         'checkCascadingSourcesRestrictions',
1618                         'checkActionPermissions',
1619                         'checkUserBlock'
1620                 );
1621
1622                 while( count( $checks ) > 0 &&
1623                            !( $short && count( $errors ) > 0 ) ) {
1624                         $method = array_shift( $checks );
1625                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1626                 }
1627
1628                 wfProfileOut( __METHOD__ );
1629                 return $errors;
1630         }
1631
1632         /**
1633          * Is this title subject to title protection?
1634          *
1635          * @return \type{\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         private function invalidateTitleProtectionCache() {
1662                 unset( $this->mTitleProtection );
1663         }
1664
1665         /**
1666          * Update the title protection status
1667          *
1668          * @param $create_perm \type{\string} Permission required for creation
1669          * @param $reason \type{\string} Reason for protection
1670          * @param $expiry \type{\string} Expiry timestamp
1671          * @return boolean true
1672          */
1673         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1674                 global $wgUser, $wgContLang;
1675
1676                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1677                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1678                         // No change
1679                         return true;
1680                 }
1681
1682                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1683
1684                 $dbw = wfGetDB( DB_MASTER );
1685
1686                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1687
1688                 $expiry_description = '';
1689                 if ( $encodedExpiry != 'infinity' ) {
1690                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1691                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1692                 } else {
1693                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1694                 }
1695
1696                 # Update protection table
1697                 if ( $create_perm != '' ) {
1698                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1699                                 array(
1700                                         'pt_namespace' => $namespace,
1701                                         'pt_title' => $title,
1702                                         'pt_create_perm' => $create_perm,
1703                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1704                                         'pt_expiry' => $encodedExpiry,
1705                                         'pt_user' => $wgUser->getId(),
1706                                         'pt_reason' => $reason,
1707                                 ), __METHOD__
1708                         );
1709                 } else {
1710                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1711                                 'pt_title' => $title ), __METHOD__ );
1712                 }
1713                 $this->invalidateTitleProtectionCache();
1714
1715                 # Update the protection log
1716                 if ( $dbw->affectedRows() ) {
1717                         $log = new LogPage( 'protect' );
1718
1719                         if ( $create_perm ) {
1720                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1721                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1722                         } else {
1723                                 $log->addEntry( 'unprotect', $this, $reason );
1724                         }
1725                 }
1726
1727                 return true;
1728         }
1729
1730         /**
1731          * Remove any title protection due to page existing
1732          */
1733         public function deleteTitleProtection() {
1734                 $dbw = wfGetDB( DB_MASTER );
1735
1736                 $dbw->delete(
1737                         'protected_titles',
1738                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1739                         __METHOD__
1740                 );
1741                 $this->invalidateTitleProtectionCache();
1742         }
1743
1744         /**
1745          * Would anybody with sufficient privileges be able to move this page?
1746          * Some pages just aren't movable.
1747          *
1748          * @return \type{\bool} TRUE or FALSE
1749          */
1750         public function isMovable() {
1751                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1752         }
1753
1754         /**
1755          * Can $wgUser read this page?
1756          *
1757          * @return \type{\bool}
1758          * @todo fold these checks into userCan()
1759          */
1760         public function userCanRead() {
1761                 global $wgUser, $wgGroupPermissions;
1762
1763                 static $useShortcut = null;
1764
1765                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1766                 if ( is_null( $useShortcut ) ) {
1767                         global $wgRevokePermissions;
1768                         $useShortcut = true;
1769                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1770                                 # Not a public wiki, so no shortcut
1771                                 $useShortcut = false;
1772                         } elseif ( !empty( $wgRevokePermissions ) ) {
1773                                 /*
1774                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1775                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1776                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1777                                  * reading is allowed.
1778                                  */
1779                                 foreach ( $wgRevokePermissions as $perms ) {
1780                                         if ( !empty( $perms['read'] ) ) {
1781                                                 # We might be removing the read right from the user, so no shortcut
1782                                                 $useShortcut = false;
1783                                                 break;
1784                                         }
1785                                 }
1786                         }
1787                 }
1788
1789                 $result = null;
1790                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1791                 if ( $result !== null ) {
1792                         return $result;
1793                 }
1794
1795                 # Shortcut for public wikis, allows skipping quite a bit of code
1796                 if ( $useShortcut ) {
1797                         return true;
1798                 }
1799
1800                 if ( $wgUser->isAllowed( 'read' ) ) {
1801                         return true;
1802                 } else {
1803                         global $wgWhitelistRead;
1804
1805                         /**
1806                          * Always grant access to the login page.
1807                          * Even anons need to be able to log in.
1808                         */
1809                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1810                                 return true;
1811                         }
1812
1813                         /**
1814                          * Bail out if there isn't whitelist
1815                          */
1816                         if ( !is_array( $wgWhitelistRead ) ) {
1817                                 return false;
1818                         }
1819
1820                         /**
1821                          * Check for explicit whitelisting
1822                          */
1823                         $name = $this->getPrefixedText();
1824                         $dbName = $this->getPrefixedDBKey();
1825                         // Check with and without underscores
1826                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1827                                 return true;
1828
1829                         /**
1830                          * Old settings might have the title prefixed with
1831                          * a colon for main-namespace pages
1832                          */
1833                         if ( $this->getNamespace() == NS_MAIN ) {
1834                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1835                                         return true;
1836                                 }
1837                         }
1838
1839                         /**
1840                          * If it's a special page, ditch the subpage bit
1841                          * and check again
1842                          */
1843                         if ( $this->getNamespace() == NS_SPECIAL ) {
1844                                 $name = $this->getDBkey();
1845                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1846                                 if ( $name === false ) {
1847                                         # Invalid special page, but we show standard login required message
1848                                         return false;
1849                                 }
1850
1851                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1852                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1853                                         return true;
1854                                 }
1855                         }
1856
1857                 }
1858                 return false;
1859         }
1860
1861         /**
1862          * Is this a talk page of some sort?
1863          *
1864          * @return \type{\bool}
1865          */
1866         public function isTalkPage() {
1867                 return MWNamespace::isTalk( $this->getNamespace() );
1868         }
1869
1870         /**
1871          * Is this a subpage?
1872          *
1873          * @return \type{\bool}
1874          */
1875         public function isSubpage() {
1876                 return MWNamespace::hasSubpages( $this->mNamespace )
1877                         ? strpos( $this->getText(), '/' ) !== false
1878                         : false;
1879         }
1880
1881         /**
1882          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1883          *
1884          * @return \type{\bool}
1885          */
1886         public function hasSubpages() {
1887                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1888                         # Duh
1889                         return false;
1890                 }
1891
1892                 # We dynamically add a member variable for the purpose of this method
1893                 # alone to cache the result.  There's no point in having it hanging
1894                 # around uninitialized in every Title object; therefore we only add it
1895                 # if needed and don't declare it statically.
1896                 if ( isset( $this->mHasSubpages ) ) {
1897                         return $this->mHasSubpages;
1898                 }
1899
1900                 $subpages = $this->getSubpages( 1 );
1901                 if ( $subpages instanceof TitleArray ) {
1902                         return $this->mHasSubpages = (bool)$subpages->count();
1903                 }
1904                 return $this->mHasSubpages = false;
1905         }
1906
1907         /**
1908          * Get all subpages of this page.
1909          *
1910          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1911          * @return mixed TitleArray, or empty array if this page's namespace
1912          *  doesn't allow subpages
1913          */
1914         public function getSubpages( $limit = -1 ) {
1915                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1916                         return array();
1917                 }
1918
1919                 $dbr = wfGetDB( DB_SLAVE );
1920                 $conds['page_namespace'] = $this->getNamespace();
1921                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1922                 $options = array();
1923                 if ( $limit > -1 ) {
1924                         $options['LIMIT'] = $limit;
1925                 }
1926                 return $this->mSubpages = TitleArray::newFromResult(
1927                         $dbr->select( 'page',
1928                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1929                                 $conds,
1930                                 __METHOD__,
1931                                 $options
1932                         )
1933                 );
1934         }
1935
1936         /**
1937          * Could this page contain custom CSS or JavaScript, based
1938          * on the title?
1939          *
1940          * @return \type{\bool}
1941          */
1942         public function isCssOrJsPage() {
1943                 return $this->mNamespace == NS_MEDIAWIKI
1944                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1945         }
1946
1947         /**
1948          * Is this a .css or .js subpage of a user page?
1949          * @return \type{\bool}
1950          */
1951         public function isCssJsSubpage() {
1952                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1953         }
1954
1955         /**
1956          * Is this a *valid* .css or .js subpage of a user page?
1957          *
1958          * @return \type{\bool}
1959          * @deprecated
1960          */
1961         public function isValidCssJsSubpage() {
1962                 return $this->isCssJsSubpage();
1963         }
1964
1965         /**
1966          * Trim down a .css or .js subpage title to get the corresponding skin name
1967          *
1968          * @return string containing skin name from .css or .js subpage title
1969          */
1970         public function getSkinFromCssJsSubpage() {
1971                 $subpage = explode( '/', $this->mTextform );
1972                 $subpage = $subpage[ count( $subpage ) - 1 ];
1973                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1974         }
1975
1976         /**
1977          * Is this a .css subpage of a user page?
1978          *
1979          * @return \type{\bool}
1980          */
1981         public function isCssSubpage() {
1982                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1983         }
1984
1985         /**
1986          * Is this a .js subpage of a user page?
1987          *
1988          * @return \type{\bool}
1989          */
1990         public function isJsSubpage() {
1991                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1992         }
1993
1994         /**
1995          * Protect css subpages of user pages: can $wgUser edit
1996          * this page?
1997          *
1998          * @return \type{\bool}
1999          * @todo XXX: this might be better using restrictions
2000          */
2001         public function userCanEditCssSubpage() {
2002                 global $wgUser;
2003                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
2004                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2005         }
2006
2007         /**
2008          * Protect js subpages of user pages: can $wgUser edit
2009          * this page?
2010          *
2011          * @return \type{\bool}
2012          * @todo XXX: this might be better using restrictions
2013          */
2014         public function userCanEditJsSubpage() {
2015                 global $wgUser;
2016                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2017                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2018         }
2019
2020         /**
2021          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2022          *
2023          * @return \type{\bool} If the page is subject to cascading restrictions.
2024          */
2025         public function isCascadeProtected() {
2026                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2027                 return ( $sources > 0 );
2028         }
2029
2030         /**
2031          * Cascading protection: Get the source of any cascading restrictions on this page.
2032          *
2033          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
2034          *        that the restrictions have come from.
2035          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
2036          *         objects of the pages from which cascading restrictions have come,
2037          *         false for none, or true if such restrictions exist, but $getPages was not set.
2038          *         The restriction array is an array of each type, each of which contains a
2039          *         array of unique groups.
2040          */
2041         public function getCascadeProtectionSources( $getPages = true ) {
2042                 $pagerestrictions = array();
2043
2044                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2045                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2046                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2047                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2048                 }
2049
2050                 wfProfileIn( __METHOD__ );
2051
2052                 $dbr = wfGetDB( DB_SLAVE );
2053
2054                 if ( $this->getNamespace() == NS_FILE ) {
2055                         $tables = array( 'imagelinks', 'page_restrictions' );
2056                         $where_clauses = array(
2057                                 'il_to' => $this->getDBkey(),
2058                                 'il_from=pr_page',
2059                                 'pr_cascade' => 1
2060                         );
2061                 } else {
2062                         $tables = array( 'templatelinks', 'page_restrictions' );
2063                         $where_clauses = array(
2064                                 'tl_namespace' => $this->getNamespace(),
2065                                 'tl_title' => $this->getDBkey(),
2066                                 'tl_from=pr_page',
2067                                 'pr_cascade' => 1
2068                         );
2069                 }
2070
2071                 if ( $getPages ) {
2072                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2073                                                    'pr_expiry', 'pr_type', 'pr_level' );
2074                         $where_clauses[] = 'page_id=pr_page';
2075                         $tables[] = 'page';
2076                 } else {
2077                         $cols = array( 'pr_expiry' );
2078                 }
2079
2080                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2081
2082                 $sources = $getPages ? array() : false;
2083                 $now = wfTimestampNow();
2084                 $purgeExpired = false;
2085
2086                 foreach ( $res as $row ) {
2087                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2088                         if ( $expiry > $now ) {
2089                                 if ( $getPages ) {
2090                                         $page_id = $row->pr_page;
2091                                         $page_ns = $row->page_namespace;
2092                                         $page_title = $row->page_title;
2093                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2094                                         # Add groups needed for each restriction type if its not already there
2095                                         # Make sure this restriction type still exists
2096
2097                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2098                                                 $pagerestrictions[$row->pr_type] = array();
2099                                         }
2100
2101                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2102                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2103                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2104                                         }
2105                                 } else {
2106                                         $sources = true;
2107                                 }
2108                         } else {
2109                                 // Trigger lazy purge of expired restrictions from the db
2110                                 $purgeExpired = true;
2111                         }
2112                 }
2113                 if ( $purgeExpired ) {
2114                         Title::purgeExpiredRestrictions();
2115                         $this->invalidateTitleProtectionCache();
2116                 }
2117
2118                 wfProfileOut( __METHOD__ );
2119
2120                 if ( $getPages ) {
2121                         $this->mCascadeSources = $sources;
2122                         $this->mCascadingRestrictions = $pagerestrictions;
2123                 } else {
2124                         $this->mHasCascadingRestrictions = $sources;
2125                 }
2126
2127                 return array( $sources, $pagerestrictions );
2128         }
2129
2130         /**
2131          * Returns cascading restrictions for the current article
2132          *
2133          * @return Boolean
2134          */
2135         function areRestrictionsCascading() {
2136                 if ( !$this->mRestrictionsLoaded ) {
2137                         $this->loadRestrictions();
2138                 }
2139
2140                 return $this->mCascadeRestriction;
2141         }
2142
2143         /**
2144          * Loads a string into mRestrictions array
2145          *
2146          * @param $res \type{Resource} restrictions as an SQL result.
2147          * @param $oldFashionedRestrictions string comma-separated list of page
2148          *        restrictions from page table (pre 1.10)
2149          */
2150         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2151                 $rows = array();
2152
2153                 foreach ( $res as $row ) {
2154                         $rows[] = $row;
2155                 }
2156
2157                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2158         }
2159
2160         /**
2161          * Compiles list of active page restrictions from both page table (pre 1.10)
2162          * and page_restrictions table
2163          *
2164          * @param $rows array of db result objects
2165          * @param $oldFashionedRestrictions string comma-separated list of page
2166          *        restrictions from page table (pre 1.10)
2167          */
2168         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2169                 $dbr = wfGetDB( DB_SLAVE );
2170
2171                 $restrictionTypes = $this->getRestrictionTypes();
2172
2173                 foreach ( $restrictionTypes as $type ) {
2174                         $this->mRestrictions[$type] = array();
2175                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2176                 }
2177
2178                 $this->mCascadeRestriction = false;
2179
2180                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2181
2182                 if ( $oldFashionedRestrictions === null ) {
2183                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2184                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2185                 }
2186
2187                 if ( $oldFashionedRestrictions != '' ) {
2188
2189                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2190                                 $temp = explode( '=', trim( $restrict ) );
2191                                 if ( count( $temp ) == 1 ) {
2192                                         // old old format should be treated as edit/move restriction
2193                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2194                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2195                                 } else {
2196                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2197                                 }
2198                         }
2199
2200                         $this->mOldRestrictions = true;
2201
2202                 }
2203
2204                 if ( count( $rows ) ) {
2205                         # Current system - load second to make them override.
2206                         $now = wfTimestampNow();
2207                         $purgeExpired = false;
2208
2209                         foreach ( $rows as $row ) {
2210                                 # Cycle through all the restrictions.
2211
2212                                 // Don't take care of restrictions types that aren't allowed
2213
2214                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2215                                         continue;
2216
2217                                 // This code should be refactored, now that it's being used more generally,
2218                                 // But I don't really see any harm in leaving it in Block for now -werdna
2219                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2220
2221                                 // Only apply the restrictions if they haven't expired!
2222                                 if ( !$expiry || $expiry > $now ) {
2223                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2224                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2225
2226                                         $this->mCascadeRestriction |= $row->pr_cascade;
2227                                 } else {
2228                                         // Trigger a lazy purge of expired restrictions
2229                                         $purgeExpired = true;
2230                                 }
2231                         }
2232
2233                         if ( $purgeExpired ) {
2234                                 Title::purgeExpiredRestrictions();
2235                                 $this->invalidateTitleProtectionCache();
2236                         }
2237                 }
2238
2239                 $this->mRestrictionsLoaded = true;
2240         }
2241
2242         /**
2243          * Load restrictions from the page_restrictions table
2244          *
2245          * @param $oldFashionedRestrictions string comma-separated list of page
2246          *        restrictions from page table (pre 1.10)
2247          */
2248         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2249                 if ( !$this->mRestrictionsLoaded ) {
2250                         if ( $this->exists() ) {
2251                                 $dbr = wfGetDB( DB_SLAVE );
2252
2253                                 $res = $dbr->select( 'page_restrictions', '*',
2254                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2255
2256                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2257                         } else {
2258                                 $title_protection = $this->getTitleProtection();
2259
2260                                 if ( $title_protection ) {
2261                                         $now = wfTimestampNow();
2262                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2263
2264                                         if ( !$expiry || $expiry > $now ) {
2265                                                 // Apply the restrictions
2266                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2267                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2268                                         } else { // Get rid of the old restrictions
2269                                                 Title::purgeExpiredRestrictions();
2270                                                 $this->invalidateTitleProtectionCache();
2271                                         }
2272                                 } else {
2273                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2274                                 }
2275                                 $this->mRestrictionsLoaded = true;
2276                         }
2277                 }
2278         }
2279
2280         /**
2281          * Purge expired restrictions from the page_restrictions table
2282          */
2283         static function purgeExpiredRestrictions() {
2284                 $dbw = wfGetDB( DB_MASTER );
2285                 $dbw->delete(
2286                         'page_restrictions',
2287                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2288                         __METHOD__
2289                 );
2290
2291                 $dbw->delete(
2292                         'protected_titles',
2293                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2294                         __METHOD__
2295                 );
2296         }
2297
2298         /**
2299          * Accessor/initialisation for mRestrictions
2300          *
2301          * @param $action \type{\string} action that permission needs to be checked for
2302          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2303          */
2304         public function getRestrictions( $action ) {
2305                 if ( !$this->mRestrictionsLoaded ) {
2306                         $this->loadRestrictions();
2307                 }
2308                 return isset( $this->mRestrictions[$action] )
2309                                 ? $this->mRestrictions[$action]
2310                                 : array();
2311         }
2312
2313         /**
2314          * Get the expiry time for the restriction against a given action
2315          *
2316          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2317          *      or not protected at all, or false if the action is not recognised.
2318          */
2319         public function getRestrictionExpiry( $action ) {
2320                 if ( !$this->mRestrictionsLoaded ) {
2321                         $this->loadRestrictions();
2322                 }
2323                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2324         }
2325
2326         /**
2327          * Is there a version of this page in the deletion archive?
2328          *
2329          * @return \type{\int} the number of archived revisions
2330          */
2331         public function isDeleted() {
2332                 if ( $this->getNamespace() < 0 ) {
2333                         $n = 0;
2334                 } else {
2335                         $dbr = wfGetDB( DB_SLAVE );
2336                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2337                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2338                                 __METHOD__
2339                         );
2340                         if ( $this->getNamespace() == NS_FILE ) {
2341                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2342                                         array( 'fa_name' => $this->getDBkey() ),
2343                                         __METHOD__
2344                                 );
2345                         }
2346                 }
2347                 return (int)$n;
2348         }
2349
2350         /**
2351          * Is there a version of this page in the deletion archive?
2352          *
2353          * @return Boolean
2354          */
2355         public function isDeletedQuick() {
2356                 if ( $this->getNamespace() < 0 ) {
2357                         return false;
2358                 }
2359                 $dbr = wfGetDB( DB_SLAVE );
2360                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2361                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2362                         __METHOD__
2363                 );
2364                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2365                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2366                                 array( 'fa_name' => $this->getDBkey() ),
2367                                 __METHOD__
2368                         );
2369                 }
2370                 return $deleted;
2371         }
2372
2373         /**
2374          * Get the article ID for this Title from the link cache,
2375          * adding it if necessary
2376          *
2377          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2378          *  for update
2379          * @return \type{\int} the ID
2380          */
2381         public function getArticleID( $flags = 0 ) {
2382                 if ( $this->getNamespace() < 0 ) {
2383                         return $this->mArticleID = 0;
2384                 }
2385                 $linkCache = LinkCache::singleton();
2386                 if ( $flags & self::GAID_FOR_UPDATE ) {
2387                         $oldUpdate = $linkCache->forUpdate( true );
2388                         $linkCache->clearLink( $this );
2389                         $this->mArticleID = $linkCache->addLinkObj( $this );
2390                         $linkCache->forUpdate( $oldUpdate );
2391                 } else {
2392                         if ( -1 == $this->mArticleID ) {
2393                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2394                         }
2395                 }
2396                 return $this->mArticleID;
2397         }
2398
2399         /**
2400          * Is this an article that is a redirect page?
2401          * Uses link cache, adding it if necessary
2402          *
2403          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2404          * @return \type{\bool}
2405          */
2406         public function isRedirect( $flags = 0 ) {
2407                 if ( !is_null( $this->mRedirect ) ) {
2408                         return $this->mRedirect;
2409                 }
2410                 # Calling getArticleID() loads the field from cache as needed
2411                 if ( !$this->getArticleID( $flags ) ) {
2412                         return $this->mRedirect = false;
2413                 }
2414                 $linkCache = LinkCache::singleton();
2415                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2416
2417                 return $this->mRedirect;
2418         }
2419
2420         /**
2421          * What is the length of this page?
2422          * Uses link cache, adding it if necessary
2423          *
2424          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2425          * @return \type{\int}
2426          */
2427         public function getLength( $flags = 0 ) {
2428                 if ( $this->mLength != -1 ) {
2429                         return $this->mLength;
2430                 }
2431                 # Calling getArticleID() loads the field from cache as needed
2432                 if ( !$this->getArticleID( $flags ) ) {
2433                         return $this->mLength = 0;
2434                 }
2435                 $linkCache = LinkCache::singleton();
2436                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2437
2438                 return $this->mLength;
2439         }
2440
2441         /**
2442          * What is the page_latest field for this page?
2443          *
2444          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2445          * @return \type{\int} or 0 if the page doesn't exist
2446          */
2447         public function getLatestRevID( $flags = 0 ) {
2448                 if ( $this->mLatestID !== false ) {
2449                         return intval( $this->mLatestID );
2450                 }
2451                 # Calling getArticleID() loads the field from cache as needed
2452                 if ( !$this->getArticleID( $flags ) ) {
2453                         return $this->mLatestID = 0;
2454                 }
2455                 $linkCache = LinkCache::singleton();
2456                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2457
2458                 return $this->mLatestID;
2459         }
2460
2461         /**
2462          * This clears some fields in this object, and clears any associated
2463          * keys in the "bad links" section of the link cache.
2464          *
2465          * - This is called from Article::doEdit() and Article::insertOn() to allow
2466          * loading of the new page_id. It's also called from
2467          * Article::doDeleteArticle()
2468          *
2469          * @param $newid \type{\int} the new Article ID
2470          */
2471         public function resetArticleID( $newid ) {
2472                 $linkCache = LinkCache::singleton();
2473                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2474
2475                 if ( $newid === false ) {
2476                         $this->mArticleID = -1;
2477                 } else {
2478                         $this->mArticleID = intval( $newid );
2479                 }
2480                 $this->mRestrictionsLoaded = false;
2481                 $this->mRestrictions = array();
2482                 $this->mRedirect = null;
2483                 $this->mLength = -1;
2484                 $this->mLatestID = false;
2485         }
2486
2487         /**
2488          * Updates page_touched for this page; called from LinksUpdate.php
2489          *
2490          * @return \type{\bool} true if the update succeded
2491          */
2492         public function invalidateCache() {
2493                 if ( wfReadOnly() ) {
2494                         return;
2495                 }
2496                 $dbw = wfGetDB( DB_MASTER );
2497                 $success = $dbw->update(
2498                         'page',
2499                         array( 'page_touched' => $dbw->timestamp() ),
2500                         $this->pageCond(),
2501                         __METHOD__
2502                 );
2503                 HTMLFileCache::clearFileCache( $this );
2504                 return $success;
2505         }
2506
2507         /**
2508          * Prefix some arbitrary text with the namespace or interwiki prefix
2509          * of this object
2510          *
2511          * @param $name \type{\string} the text
2512          * @return \type{\string} the prefixed text
2513          * @private
2514          */
2515         /* private */ function prefix( $name ) {
2516                 $p = '';
2517                 if ( $this->mInterwiki != '' ) {
2518                         $p = $this->mInterwiki . ':';
2519                 }
2520                 if ( 0 != $this->mNamespace ) {
2521                         $p .= $this->getNsText() . ':';
2522                 }
2523                 return $p . $name;
2524         }
2525
2526         /**
2527          * Returns a simple regex that will match on characters and sequences invalid in titles.
2528          * Note that this doesn't pick up many things that could be wrong with titles, but that
2529          * replacing this regex with something valid will make many titles valid.
2530          *
2531          * @return string regex string
2532          */
2533         static function getTitleInvalidRegex() {
2534                 static $rxTc = false;
2535                 if ( !$rxTc ) {
2536                         # Matching titles will be held as illegal.
2537                         $rxTc = '/' .
2538                                 # Any character not allowed is forbidden...
2539                                 '[^' . Title::legalChars() . ']' .
2540                                 # URL percent encoding sequences interfere with the ability
2541                                 # to round-trip titles -- you can't link to them consistently.
2542                                 '|%[0-9A-Fa-f]{2}' .
2543                                 # XML/HTML character references produce similar issues.
2544                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2545                                 '|&#[0-9]+;' .
2546                                 '|&#x[0-9A-Fa-f]+;' .
2547                                 '/S';
2548                 }
2549
2550                 return $rxTc;
2551         }
2552
2553         /**
2554          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2555          *
2556          * @param $text string containing title to capitalize
2557          * @param $ns int namespace index, defaults to NS_MAIN
2558          * @return String containing capitalized title
2559          */
2560         public static function capitalize( $text, $ns = NS_MAIN ) {
2561                 global $wgContLang;
2562
2563                 if ( MWNamespace::isCapitalized( $ns ) ) {
2564                         return $wgContLang->ucfirst( $text );
2565                 } else {
2566                         return $text;
2567                 }
2568         }
2569
2570         /**
2571          * Secure and split - main initialisation function for this object
2572          *
2573          * Assumes that mDbkeyform has been set, and is urldecoded
2574          * and uses underscores, but not otherwise munged.  This function
2575          * removes illegal characters, splits off the interwiki and
2576          * namespace prefixes, sets the other forms, and canonicalizes
2577          * everything.
2578          *
2579          * @return \type{\bool} true on success
2580          */
2581         private function secureAndSplit() {
2582                 global $wgContLang, $wgLocalInterwiki;
2583
2584                 # Initialisation
2585                 $rxTc = self::getTitleInvalidRegex();
2586
2587                 $this->mInterwiki = $this->mFragment = '';
2588                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2589
2590                 $dbkey = $this->mDbkeyform;
2591
2592                 # Strip Unicode bidi override characters.
2593                 # Sometimes they slip into cut-n-pasted page titles, where the
2594                 # override chars get included in list displays.
2595                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2596
2597                 # Clean up whitespace
2598                 # Note: use of the /u option on preg_replace here will cause
2599                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2600                 # conveniently disabling them.
2601                 #
2602                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2603                 $dbkey = trim( $dbkey, '_' );
2604
2605                 if ( $dbkey == '' ) {
2606                         return false;
2607                 }
2608
2609                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2610                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2611                         return false;
2612                 }
2613
2614                 $this->mDbkeyform = $dbkey;
2615
2616                 # Initial colon indicates main namespace rather than specified default
2617                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2618                 if ( ':' == $dbkey { 0 } ) {
2619                         $this->mNamespace = NS_MAIN;
2620                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2621                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2622                 }
2623
2624                 # Namespace or interwiki prefix
2625                 $firstPass = true;
2626                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2627                 do {
2628                         $m = array();
2629                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2630                                 $p = $m[1];
2631                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2632                                         # Ordinary namespace
2633                                         $dbkey = $m[2];
2634                                         $this->mNamespace = $ns;
2635                                         # For Talk:X pages, check if X has a "namespace" prefix
2636                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2637                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2638                                                         return false; # Disallow Talk:File:x type titles...
2639                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2640                                                         return false; # Disallow Talk:Interwiki:x type titles...
2641                                                 }
2642                                         }
2643                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2644                                         if ( !$firstPass ) {
2645                                                 # Can't make a local interwiki link to an interwiki link.
2646                                                 # That's just crazy!
2647                                                 return false;
2648                                         }
2649
2650                                         # Interwiki link
2651                                         $dbkey = $m[2];
2652                                         $this->mInterwiki = $wgContLang->lc( $p );
2653
2654                                         # Redundant interwiki prefix to the local wiki
2655                                         if ( $wgLocalInterwiki !== false
2656                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2657                                         {
2658                                                 if ( $dbkey == '' ) {
2659                                                         # Can't have an empty self-link
2660                                                         return false;
2661                                                 }
2662                                                 $this->mInterwiki = '';
2663                                                 $firstPass = false;
2664                                                 # Do another namespace split...
2665                                                 continue;
2666                                         }
2667
2668                                         # If there's an initial colon after the interwiki, that also
2669                                         # resets the default namespace
2670                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2671                                                 $this->mNamespace = NS_MAIN;
2672                                                 $dbkey = substr( $dbkey, 1 );
2673                                         }
2674                                 }
2675                                 # If there's no recognized interwiki or namespace,
2676                                 # then let the colon expression be part of the title.
2677                         }
2678                         break;
2679                 } while ( true );
2680
2681                 # We already know that some pages won't be in the database!
2682                 #
2683                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2684                         $this->mArticleID = 0;
2685                 }
2686                 $fragment = strstr( $dbkey, '#' );
2687                 if ( false !== $fragment ) {
2688                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2689                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2690                         # remove whitespace again: prevents "Foo_bar_#"
2691                         # becoming "Foo_bar_"
2692                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2693                 }
2694
2695                 # Reject illegal characters.
2696                 #
2697                 if ( preg_match( $rxTc, $dbkey ) ) {
2698                         return false;
2699                 }
2700
2701                 /**
2702                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2703                  * reachable due to the way web browsers deal with 'relative' URLs.
2704                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2705                  */
2706                 if ( strpos( $dbkey, '.' ) !== false &&
2707                      ( $dbkey === '.' || $dbkey === '..' ||
2708                        strpos( $dbkey, './' ) === 0  ||
2709                        strpos( $dbkey, '../' ) === 0 ||
2710                        strpos( $dbkey, '/./' ) !== false ||
2711                        strpos( $dbkey, '/../' ) !== false  ||
2712                        substr( $dbkey, -2 ) == '/.' ||
2713                        substr( $dbkey, -3 ) == '/..' ) )
2714                 {
2715                         return false;
2716                 }
2717
2718                 /**
2719                  * Magic tilde sequences? Nu-uh!
2720                  */
2721                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2722                         return false;
2723                 }
2724
2725                 /**
2726                  * Limit the size of titles to 255 bytes.
2727                  * This is typically the size of the underlying database field.
2728                  * We make an exception for special pages, which don't need to be stored
2729                  * in the database, and may edge over 255 bytes due to subpage syntax
2730                  * for long titles, e.g. [[Special:Block/Long name]]
2731                  */
2732                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2733                   strlen( $dbkey ) > 512 )
2734                 {
2735                         return false;
2736                 }
2737
2738                 /**
2739                  * Normally, all wiki links are forced to have
2740                  * an initial capital letter so [[foo]] and [[Foo]]
2741                  * point to the same place.
2742                  *
2743                  * Don't force it for interwikis, since the other
2744                  * site might be case-sensitive.
2745                  */
2746                 $this->mUserCaseDBKey = $dbkey;
2747                 if ( $this->mInterwiki == '' ) {
2748                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2749                 }
2750
2751                 /**
2752                  * Can't make a link to a namespace alone...
2753                  * "empty" local links can only be self-links
2754                  * with a fragment identifier.
2755                  */
2756                 if ( $dbkey == '' &&
2757                         $this->mInterwiki == '' &&
2758                         $this->mNamespace != NS_MAIN ) {
2759                         return false;
2760                 }
2761                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2762                 // IP names are not allowed for accounts, and can only be referring to
2763                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2764                 // there are numerous ways to present the same IP. Having sp:contribs scan
2765                 // them all is silly and having some show the edits and others not is
2766                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2767                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2768                         IP::sanitizeIP( $dbkey ) : $dbkey;
2769                 // Any remaining initial :s are illegal.
2770                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2771                         return false;
2772                 }
2773
2774                 # Fill fields
2775                 $this->mDbkeyform = $dbkey;
2776                 $this->mUrlform = wfUrlencode( $dbkey );
2777
2778                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2779
2780                 return true;
2781         }
2782
2783         /**
2784          * Set the fragment for this title. Removes the first character from the
2785          * specified fragment before setting, so it assumes you're passing it with
2786          * an initial "#".
2787          *
2788          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2789          * Still in active use privately.
2790          *
2791          * @param $fragment \type{\string} text
2792          */
2793         public function setFragment( $fragment ) {
2794                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2795         }
2796
2797         /**
2798          * Get a Title object associated with the talk page of this article
2799          *
2800          * @return Title the object for the talk page
2801          */
2802         public function getTalkPage() {
2803                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2804         }
2805
2806         /**
2807          * Get a title object associated with the subject page of this
2808          * talk page
2809          *
2810          * @return Title the object for the subject page
2811          */
2812         public function getSubjectPage() {
2813                 // Is this the same title?
2814                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2815                 if ( $this->getNamespace() == $subjectNS ) {
2816                         return $this;
2817                 }
2818                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2819         }
2820
2821         /**
2822          * Get an array of Title objects linking to this Title
2823          * Also stores the IDs in the link cache.
2824          *
2825          * WARNING: do not use this function on arbitrary user-supplied titles!
2826          * On heavily-used templates it will max out the memory.
2827          *
2828          * @param $options Array: may be FOR UPDATE
2829          * @param $table String: table name
2830          * @param $prefix String: fields prefix
2831          * @return \type{\arrayof{Title}} the Title objects linking here
2832          */
2833         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2834                 $linkCache = LinkCache::singleton();
2835
2836                 if ( count( $options ) > 0 ) {
2837                         $db = wfGetDB( DB_MASTER );
2838                 } else {
2839                         $db = wfGetDB( DB_SLAVE );
2840                 }
2841
2842                 $res = $db->select(
2843                         array( 'page', $table ),
2844                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2845                         array(
2846                                 "{$prefix}_from=page_id",
2847                                 "{$prefix}_namespace" => $this->getNamespace(),
2848                                 "{$prefix}_title"     => $this->getDBkey() ),
2849                         __METHOD__,
2850                         $options
2851                 );
2852
2853                 $retVal = array();
2854                 if ( $db->numRows( $res ) ) {
2855                         foreach ( $res as $row ) {
2856                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2857                                 if ( $titleObj ) {
2858                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2859                                         $retVal[] = $titleObj;
2860                                 }
2861                         }
2862                 }
2863                 return $retVal;
2864         }
2865
2866         /**
2867          * Get an array of Title objects using this Title as a template
2868          * Also stores the IDs in the link cache.
2869          *
2870          * WARNING: do not use this function on arbitrary user-supplied titles!
2871          * On heavily-used templates it will max out the memory.
2872          *
2873          * @param $options Array: may be FOR UPDATE
2874          * @return \type{\arrayof{Title}} the Title objects linking here
2875          */
2876         public function getTemplateLinksTo( $options = array() ) {
2877                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2878         }
2879
2880         /**
2881          * Get an array of Title objects referring to non-existent articles linked from this page
2882          *
2883          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2884          * @return \type{\arrayof{Title}} the Title objects
2885          */
2886         public function getBrokenLinksFrom() {
2887                 if ( $this->getArticleId() == 0 ) {
2888                         # All links from article ID 0 are false positives
2889                         return array();
2890                 }
2891
2892                 $dbr = wfGetDB( DB_SLAVE );
2893                 $res = $dbr->select(
2894                         array( 'page', 'pagelinks' ),
2895                         array( 'pl_namespace', 'pl_title' ),
2896                         array(
2897                                 'pl_from' => $this->getArticleId(),
2898                                 'page_namespace IS NULL'
2899                         ),
2900                         __METHOD__, array(),
2901                         array(
2902                                 'page' => array(
2903                                         'LEFT JOIN',
2904                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2905                                 )
2906                         )
2907                 );
2908
2909                 $retVal = array();
2910                 foreach ( $res as $row ) {
2911                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2912                 }
2913                 return $retVal;
2914         }
2915
2916
2917         /**
2918          * Get a list of URLs to purge from the Squid cache when this
2919          * page changes
2920          *
2921          * @return \type{\arrayof{\string}} the URLs
2922          */
2923         public function getSquidURLs() {
2924                 global $wgContLang;
2925
2926                 $urls = array(
2927                         $this->getInternalURL(),
2928                         $this->getInternalURL( 'action=history' )
2929                 );
2930
2931                 // purge variant urls as well
2932                 if ( $wgContLang->hasVariants() ) {
2933                         $variants = $wgContLang->getVariants();
2934                         foreach ( $variants as $vCode ) {
2935                                 $urls[] = $this->getInternalURL( '', $vCode );
2936                         }
2937                 }
2938
2939                 return $urls;
2940         }
2941
2942         /**
2943          * Purge all applicable Squid URLs
2944          */
2945         public function purgeSquid() {
2946                 global $wgUseSquid;
2947                 if ( $wgUseSquid ) {
2948                         $urls = $this->getSquidURLs();
2949                         $u = new SquidUpdate( $urls );
2950                         $u->doUpdate();
2951                 }
2952         }
2953
2954         /**
2955          * Move this page without authentication
2956          *
2957          * @param $nt \type{Title} the new page Title
2958          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2959          */
2960         public function moveNoAuth( &$nt ) {
2961                 return $this->moveTo( $nt, false );
2962         }
2963
2964         /**
2965          * Check whether a given move operation would be valid.
2966          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2967          *
2968          * @param $nt \type{Title} the new title
2969          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2970          *  should be checked
2971          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2972          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2973          */
2974         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2975                 global $wgUser;
2976
2977                 $errors = array();
2978                 if ( !$nt ) {
2979                         // Normally we'd add this to $errors, but we'll get
2980                         // lots of syntax errors if $nt is not an object
2981                         return array( array( 'badtitletext' ) );
2982                 }
2983                 if ( $this->equals( $nt ) ) {
2984                         $errors[] = array( 'selfmove' );
2985                 }
2986                 if ( !$this->isMovable() ) {
2987                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2988                 }
2989                 if ( $nt->getInterwiki() != '' ) {
2990                         $errors[] = array( 'immobile-target-namespace-iw' );
2991                 }
2992                 if ( !$nt->isMovable() ) {
2993                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2994                 }
2995
2996                 $oldid = $this->getArticleID();
2997                 $newid = $nt->getArticleID();
2998
2999                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3000                         $errors[] = array( 'articleexists' );
3001                 }
3002                 if ( ( $this->getDBkey() == '' ) ||
3003                          ( !$oldid ) ||
3004                      ( $nt->getDBkey() == '' ) ) {
3005                         $errors[] = array( 'badarticleerror' );
3006                 }
3007
3008                 // Image-specific checks
3009                 if ( $this->getNamespace() == NS_FILE ) {
3010                         if ( $nt->getNamespace() != NS_FILE ) {
3011                                 $errors[] = array( 'imagenocrossnamespace' );
3012                         }
3013                         $file = wfLocalFile( $this );
3014                         if ( $file->exists() ) {
3015                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3016                                         $errors[] = array( 'imageinvalidfilename' );
3017                                 }
3018                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3019                                         $errors[] = array( 'imagetypemismatch' );
3020                                 }
3021                         }
3022                         $destfile = wfLocalFile( $nt );
3023                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3024                                 $errors[] = array( 'file-exists-sharedrepo' );
3025                         }
3026                 }
3027
3028                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3029                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3030                 }
3031
3032                 if ( $auth ) {
3033                         $errors = wfMergeErrorArrays( $errors,
3034                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3035                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3036                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3037                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3038                 }
3039
3040                 $match = EditPage::matchSummarySpamRegex( $reason );
3041                 if ( $match !== false ) {
3042                         // This is kind of lame, won't display nice
3043                         $errors[] = array( 'spamprotectiontext' );
3044                 }
3045
3046                 $err = null;
3047                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3048                         $errors[] = array( 'hookaborted', $err );
3049                 }
3050
3051                 # The move is allowed only if (1) the target doesn't exist, or
3052                 # (2) the target is a redirect to the source, and has no history
3053                 # (so we can undo bad moves right after they're done).
3054
3055                 if ( 0 != $newid ) { # Target exists; check for validity
3056                         if ( !$this->isValidMoveTarget( $nt ) ) {
3057                                 $errors[] = array( 'articleexists' );
3058                         }
3059                 } else {
3060                         $tp = $nt->getTitleProtection();
3061                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3062                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3063                                 $errors[] = array( 'cantmove-titleprotected' );
3064                         }
3065                 }
3066                 if ( empty( $errors ) ) {
3067                         return true;
3068                 }
3069                 return $errors;
3070         }
3071
3072         /**
3073          * Move a title to a new location
3074          *
3075          * @param $nt \type{Title} the new title
3076          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3077          *  should be checked
3078          * @param $reason \type{\string} The reason for the move
3079          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3080          *  Ignored if the user doesn't have the suppressredirect right.
3081          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3082          */
3083         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3084                 global $wgContLang;
3085
3086                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3087                 if ( is_array( $err ) ) {
3088                         return $err;
3089                 }
3090
3091                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3092                 $dbw = wfGetDB( DB_MASTER );
3093                 if ( $this->getNamespace() == NS_FILE ) {
3094                         $file = wfLocalFile( $this );
3095                         if ( $file->exists() ) {
3096                                 $status = $file->move( $nt );
3097                                 if ( !$status->isOk() ) {
3098                                         return $status->getErrorsArray();
3099                                 }
3100                         }
3101                 }
3102
3103                 $pageid = $this->getArticleID();
3104                 $protected = $this->isProtected();
3105                 if ( $nt->exists() ) {
3106                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3107                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3108                 } else { # Target didn't exist, do normal move.
3109                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3110                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3111                 }
3112
3113                 if ( is_array( $err ) ) {
3114                         return $err;
3115                 }
3116                 $redirid = $this->getArticleID();
3117
3118                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3119                 // cl_timestamp, which may disturb time-based lists on some sites.
3120                 $prefix = $dbw->selectField(
3121                         'categorylinks',
3122                         'cl_sortkey_prefix',
3123                         array( 'cl_from' => $pageid ),
3124                         __METHOD__
3125                 );
3126                 $dbw->update( 'categorylinks',
3127                         array(
3128                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3129                                 'cl_timestamp=cl_timestamp' ),
3130                         array( 'cl_from' => $pageid ),
3131                         __METHOD__ );
3132
3133                 if ( $protected ) {
3134                         # Protect the redirect title as the title used to be...
3135                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3136                                 array(
3137                                         'pr_page'    => $redirid,
3138                                         'pr_type'    => 'pr_type',
3139                                         'pr_level'   => 'pr_level',
3140                                         'pr_cascade' => 'pr_cascade',
3141                                         'pr_user'    => 'pr_user',
3142                                         'pr_expiry'  => 'pr_expiry'
3143                                 ),
3144                                 array( 'pr_page' => $pageid ),
3145                                 __METHOD__,
3146                                 array( 'IGNORE' )
3147                         );
3148                         # Update the protection log
3149                         $log = new LogPage( 'protect' );
3150                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3151                         if ( $reason ) {
3152                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3153                         }
3154                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3155                 }
3156
3157                 # Update watchlists
3158                 $oldnamespace = $this->getNamespace() & ~1;
3159                 $newnamespace = $nt->getNamespace() & ~1;
3160                 $oldtitle = $this->getDBkey();
3161                 $newtitle = $nt->getDBkey();
3162
3163                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3164                         WatchedItem::duplicateEntries( $this, $nt );
3165                 }
3166
3167                 # Update search engine
3168                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3169                 $u->doUpdate();
3170                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3171                 $u->doUpdate();
3172
3173                 # Update site_stats
3174                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3175                         # No longer a content page
3176                         # Not viewed, edited, removing
3177                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3178                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3179                         # Now a content page
3180                         # Not viewed, edited, adding
3181                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3182                 } elseif ( $pageCountChange ) {
3183                         # Redirect added
3184                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3185                 } else {
3186                         # Nothing special
3187                         $u = false;
3188                 }
3189                 if ( $u ) {
3190                         $u->doUpdate();
3191                 }
3192                 # Update message cache for interface messages
3193                 global $wgMessageCache;
3194                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3195                         # @bug 17860: old article can be deleted, if this the case,
3196                         # delete it from message cache
3197                         if ( $this->getArticleID() === 0 ) {
3198                                 $wgMessageCache->replace( $this->getDBkey(), false );
3199                         } else {
3200                                 $oldarticle = new Article( $this );
3201                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3202                         }
3203                 }
3204                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3205                         $newarticle = new Article( $nt );
3206                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3207                 }
3208
3209                 global $wgUser;
3210                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3211                 return true;
3212         }
3213
3214         /**
3215          * Move page to a title which is at present a redirect to the
3216          * source page
3217          *
3218          * @param $nt \type{Title} the page to move to, which should currently
3219          *  be a redirect
3220          * @param $reason \type{\string} The reason for the move
3221          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3222          *  Ignored if the user doesn't have the suppressredirect right
3223          */
3224         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3225                 global $wgUseSquid, $wgUser, $wgContLang;
3226
3227                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3228
3229                 if ( $reason ) {
3230                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3231                 }
3232                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3233                 $comment = $wgContLang->truncate( $comment, 250 );
3234
3235                 $now = wfTimestampNow();
3236                 $newid = $nt->getArticleID();
3237                 $oldid = $this->getArticleID();
3238                 $latest = $this->getLatestRevID();
3239
3240                 $dbw = wfGetDB( DB_MASTER );
3241
3242                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3243                 $newns = $nt->getNamespace();
3244                 $newdbk = $nt->getDBkey();
3245
3246                 # Delete the old redirect. We don't save it to history since
3247                 # by definition if we've got here it's rather uninteresting.
3248                 # We have to remove it so that the next step doesn't trigger
3249                 # a conflict on the unique namespace+title index...
3250                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3251                 if ( !$dbw->cascadingDeletes() ) {
3252                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3253                         global $wgUseTrackbacks;
3254                         if ( $wgUseTrackbacks ) {
3255                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3256                         }
3257                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3258                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3259                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3260                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3261                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3262                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3263                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3264                 }
3265                 // If the redirect was recently created, it may have an entry in recentchanges still
3266                 $dbw->delete( 'recentchanges',
3267                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3268                         __METHOD__
3269                 );
3270
3271                 # Save a null revision in the page's history notifying of the move
3272                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
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( $now ),
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                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3324
3325                 # Purge squid
3326                 if ( $wgUseSquid ) {
3327                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3328                         $u = new SquidUpdate( $urls );
3329                         $u->doUpdate();
3330                 }
3331
3332         }
3333
3334         /**
3335          * Move page to non-existing title.
3336          *
3337          * @param $nt \type{Title} the new Title
3338          * @param $reason \type{\string} The reason for the move
3339          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3340          *  Ignored if the user doesn't have the suppressredirect right
3341          */
3342         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3343                 global $wgUser, $wgContLang;
3344
3345                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3346                 if ( $reason ) {
3347                         $comment .= wfMsgExt( 'colon-separator',
3348                                 array( 'escapenoentities', 'content' ) );
3349                         $comment .= $reason;
3350                 }
3351                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3352                 $comment = $wgContLang->truncate( $comment, 250 );
3353
3354                 $oldid = $this->getArticleID();
3355                 $latest = $this->getLatestRevId();
3356
3357                 $dbw = wfGetDB( DB_MASTER );
3358                 $now = $dbw->timestamp();
3359
3360                 # Save a null revision in the page's history notifying of the move
3361                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3362                 if ( !is_object( $nullRevision ) ) {
3363                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3364                 }
3365                 $nullRevId = $nullRevision->insertOn( $dbw );
3366
3367                 $article = new Article( $this );
3368                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3369
3370                 # Rename page entry
3371                 $dbw->update( 'page',
3372                         /* SET */ array(
3373                                 'page_touched'   => $now,
3374                                 'page_namespace' => $nt->getNamespace(),
3375                                 'page_title'     => $nt->getDBkey(),
3376                                 'page_latest'    => $nullRevId,
3377                         ),
3378                         /* WHERE */ array( 'page_id' => $oldid ),
3379                         __METHOD__
3380                 );
3381                 $nt->resetArticleID( $oldid );
3382
3383                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3384                         # Insert redirect
3385                         $mwRedir = MagicWord::get( 'redirect' );
3386                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3387                         $redirectArticle = new Article( $this );
3388                         $newid = $redirectArticle->insertOn( $dbw );
3389                         $redirectRevision = new Revision( array(
3390                                 'page'    => $newid,
3391                                 'comment' => $comment,
3392                                 'text'    => $redirectText ) );
3393                         $redirectRevision->insertOn( $dbw );
3394                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3395
3396                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3397
3398                         # Record the just-created redirect's linking to the page
3399                         $dbw->insert( 'pagelinks',
3400                                 array(
3401                                         'pl_from'      => $newid,
3402                                         'pl_namespace' => $nt->getNamespace(),
3403                                         'pl_title'     => $nt->getDBkey() ),
3404                                 __METHOD__ );
3405                         $redirectSuppressed = false;
3406                 } else {
3407                         $this->resetArticleID( 0 );
3408                         $redirectSuppressed = true;
3409                 }
3410
3411                 # Log the move
3412                 $log = new LogPage( 'move' );
3413                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3414
3415                 # Purge caches as per article creation
3416                 Article::onArticleCreate( $nt );
3417
3418                 # Purge old title from squid
3419                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3420                 $this->purgeSquid();
3421         }
3422
3423         /**
3424          * Move this page's subpages to be subpages of $nt
3425          *
3426          * @param $nt Title Move target
3427          * @param $auth bool Whether $wgUser's permissions should be checked
3428          * @param $reason string The reason for the move
3429          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3430          *  Ignored if the user doesn't have the 'suppressredirect' right
3431          * @return mixed array with old page titles as keys, and strings (new page titles) or
3432          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3433          */
3434         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3435                 global $wgMaximumMovedPages;
3436                 // Check permissions
3437                 if ( !$this->userCan( 'move-subpages' ) ) {
3438                         return array( 'cant-move-subpages' );
3439                 }
3440                 // Do the source and target namespaces support subpages?
3441                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3442                         return array( 'namespace-nosubpages',
3443                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3444                 }
3445                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3446                         return array( 'namespace-nosubpages',
3447                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3448                 }
3449
3450                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3451                 $retval = array();
3452                 $count = 0;
3453                 foreach ( $subpages as $oldSubpage ) {
3454                         $count++;
3455                         if ( $count > $wgMaximumMovedPages ) {
3456                                 $retval[$oldSubpage->getPrefixedTitle()] =
3457                                                 array( 'movepage-max-pages',
3458                                                         $wgMaximumMovedPages );
3459                                 break;
3460                         }
3461
3462                         // We don't know whether this function was called before
3463                         // or after moving the root page, so check both
3464                         // $this and $nt
3465                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3466                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3467                         {
3468                                 // When moving a page to a subpage of itself,
3469                                 // don't move it twice
3470                                 continue;
3471                         }
3472                         $newPageName = preg_replace(
3473                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3474                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3475                                         $oldSubpage->getDBkey() );
3476                         if ( $oldSubpage->isTalkPage() ) {
3477                                 $newNs = $nt->getTalkPage()->getNamespace();
3478                         } else {
3479                                 $newNs = $nt->getSubjectPage()->getNamespace();
3480                         }
3481                         # Bug 14385: we need makeTitleSafe because the new page names may
3482                         # be longer than 255 characters.
3483                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3484
3485                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3486                         if ( $success === true ) {
3487                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3488                         } else {
3489                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3490                         }
3491                 }
3492                 return $retval;
3493         }
3494
3495         /**
3496          * Checks if this page is just a one-rev redirect.
3497          * Adds lock, so don't use just for light purposes.
3498          *
3499          * @return \type{\bool}
3500          */
3501         public function isSingleRevRedirect() {
3502                 $dbw = wfGetDB( DB_MASTER );
3503                 # Is it a redirect?
3504                 $row = $dbw->selectRow( 'page',
3505                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3506                         $this->pageCond(),
3507                         __METHOD__,
3508                         array( 'FOR UPDATE' )
3509                 );
3510                 # Cache some fields we may want
3511                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3512                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3513                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3514                 if ( !$this->mRedirect ) {
3515                         return false;
3516                 }
3517                 # Does the article have a history?
3518                 $row = $dbw->selectField( array( 'page', 'revision' ),
3519                         'rev_id',
3520                         array( 'page_namespace' => $this->getNamespace(),
3521                                 'page_title' => $this->getDBkey(),
3522                                 'page_id=rev_page',
3523                                 'page_latest != rev_id'
3524                         ),
3525                         __METHOD__,
3526                         array( 'FOR UPDATE' )
3527                 );
3528                 # Return true if there was no history
3529                 return ( $row === false );
3530         }
3531
3532         /**
3533          * Checks if $this can be moved to a given Title
3534          * - Selects for update, so don't call it unless you mean business
3535          *
3536          * @param $nt \type{Title} the new title to check
3537          * @return \type{\bool} TRUE or FALSE
3538          */
3539         public function isValidMoveTarget( $nt ) {
3540                 # Is it an existing file?
3541                 if ( $nt->getNamespace() == NS_FILE ) {
3542                         $file = wfLocalFile( $nt );
3543                         if ( $file->exists() ) {
3544                                 wfDebug( __METHOD__ . ": file exists\n" );
3545                                 return false;
3546                         }
3547                 }
3548                 # Is it a redirect with no history?
3549                 if ( !$nt->isSingleRevRedirect() ) {
3550                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3551                         return false;
3552                 }
3553                 # Get the article text
3554                 $rev = Revision::newFromTitle( $nt );
3555                 $text = $rev->getText();
3556                 # Does the redirect point to the source?
3557                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3558                 $m = array();
3559                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3560                         $redirTitle = Title::newFromText( $m[1] );
3561                         if ( !is_object( $redirTitle ) ||
3562                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3563                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3564                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3565                                 return false;
3566                         }
3567                 } else {
3568                         # Fail safe
3569                         wfDebug( __METHOD__ . ": failsafe\n" );
3570                         return false;
3571                 }
3572                 return true;
3573         }
3574
3575         /**
3576          * Can this title be added to a user's watchlist?
3577          *
3578          * @return \type{\bool} TRUE or FALSE
3579          */
3580         public function isWatchable() {
3581                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3582         }
3583
3584         /**
3585          * Get categories to which this Title belongs and return an array of
3586          * categories' names.
3587          *
3588          * @return \type{\array} array an array of parents in the form:
3589          *      $parent => $currentarticle
3590          */
3591         public function getParentCategories() {
3592                 global $wgContLang;
3593
3594                 $titlekey = $this->getArticleId();
3595                 $dbr = wfGetDB( DB_SLAVE );
3596                 $categorylinks = $dbr->tableName( 'categorylinks' );
3597
3598                 # NEW SQL
3599                 $sql = "SELECT * FROM $categorylinks"
3600                      . " WHERE cl_from='$titlekey'"
3601                          . " AND cl_from <> '0'"
3602                          . " ORDER BY cl_sortkey";
3603
3604                 $res = $dbr->query( $sql );
3605                 $data = array();
3606
3607                 if ( $dbr->numRows( $res ) > 0 ) {
3608                         foreach ( $res as $row ) {
3609                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3610                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3611                         }
3612                 }
3613                 return $data;
3614         }
3615
3616         /**
3617          * Get a tree of parent categories
3618          *
3619          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3620          * @return \type{\array} Tree of parent categories
3621          */
3622         public function getParentCategoryTree( $children = array() ) {
3623                 $stack = array();
3624                 $parents = $this->getParentCategories();
3625
3626                 if ( $parents ) {
3627                         foreach ( $parents as $parent => $current ) {
3628                                 if ( array_key_exists( $parent, $children ) ) {
3629                                         # Circular reference
3630                                         $stack[$parent] = array();
3631                                 } else {
3632                                         $nt = Title::newFromText( $parent );
3633                                         if ( $nt ) {
3634                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3635                                         }
3636                                 }
3637                         }
3638                 }
3639
3640                 return $stack;
3641         }
3642
3643
3644         /**
3645          * Get an associative array for selecting this title from
3646          * the "page" table
3647          *
3648          * @return \type{\array} Selection array
3649          */
3650         public function pageCond() {
3651                 if ( $this->mArticleID > 0 ) {
3652                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3653                         return array( 'page_id' => $this->mArticleID );
3654                 } else {
3655                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3656                 }
3657         }
3658
3659         /**
3660          * Get the revision ID of the previous revision
3661          *
3662          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3663          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3664          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3665          */
3666         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3667                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3668                 return $db->selectField( 'revision', 'rev_id',
3669                         array(
3670                                 'rev_page' => $this->getArticleId( $flags ),
3671                                 'rev_id < ' . intval( $revId )
3672                         ),
3673                         __METHOD__,
3674                         array( 'ORDER BY' => 'rev_id DESC' )
3675                 );
3676         }
3677
3678         /**
3679          * Get the revision ID of the next revision
3680          *
3681          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3682          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3683          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3684          */
3685         public function getNextRevisionID( $revId, $flags = 0 ) {
3686                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3687                 return $db->selectField( 'revision', 'rev_id',
3688                         array(
3689                                 'rev_page' => $this->getArticleId( $flags ),
3690                                 'rev_id > ' . intval( $revId )
3691                         ),
3692                         __METHOD__,
3693                         array( 'ORDER BY' => 'rev_id' )
3694                 );
3695         }
3696
3697         /**
3698          * Get the first revision of the page
3699          *
3700          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3701          * @return Revision (or NULL if page doesn't exist)
3702          */
3703         public function getFirstRevision( $flags = 0 ) {
3704                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3705                 $pageId = $this->getArticleId( $flags );
3706                 if ( !$pageId ) {
3707                         return null;
3708                 }
3709                 $row = $db->selectRow( 'revision', '*',
3710                         array( 'rev_page' => $pageId ),
3711                         __METHOD__,
3712                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3713                 );
3714                 if ( !$row ) {
3715                         return null;
3716                 } else {
3717                         return new Revision( $row );
3718                 }
3719         }
3720
3721         /**
3722          * Check if this is a new page
3723          *
3724          * @return bool
3725          */
3726         public function isNewPage() {
3727                 $dbr = wfGetDB( DB_SLAVE );
3728                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3729         }
3730
3731         /**
3732          * Get the oldest revision timestamp of this page
3733          *
3734          * @return String: MW timestamp
3735          */
3736         public function getEarliestRevTime() {
3737                 $dbr = wfGetDB( DB_SLAVE );
3738                 if ( $this->exists() ) {
3739                         $min = $dbr->selectField( 'revision',
3740                                 'MIN(rev_timestamp)',
3741                                 array( 'rev_page' => $this->getArticleId() ),
3742                                 __METHOD__ );
3743                         return wfTimestampOrNull( TS_MW, $min );
3744                 }
3745                 return null;
3746         }
3747
3748         /**
3749          * Get the number of revisions between the given revision IDs.
3750          * Used for diffs and other things that really need it.
3751          *
3752          * @param $old \type{\int} Revision ID.
3753          * @param $new \type{\int} Revision ID.
3754          * @return \type{\int} Number of revisions between these IDs.
3755          */
3756         public function countRevisionsBetween( $old, $new ) {
3757                 $dbr = wfGetDB( DB_SLAVE );
3758                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3759                                 'rev_page' => intval( $this->getArticleId() ),
3760                                 'rev_id > ' . intval( $old ),
3761                                 'rev_id < ' . intval( $new )
3762                         ), __METHOD__
3763                 );
3764         }
3765
3766         /**
3767          * Get the number of authors between the given revision IDs.
3768          * Used for diffs and other things that really need it.
3769          *
3770          * @param $fromRevId \type{\int} Revision ID (first before range)
3771          * @param $toRevId \type{\int} Revision ID (first after range)
3772          * @param $limit \type{\int} Maximum number of authors
3773          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3774          * @return \type{\int}
3775          */
3776         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3777                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3778                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3779                         array(
3780                                 'rev_page' => $this->getArticleID(),
3781                                 'rev_id > ' . (int)$fromRevId,
3782                                 'rev_id < ' . (int)$toRevId
3783                         ), __METHOD__,
3784                         array( 'LIMIT' => $limit )
3785                 );
3786                 return (int)$db->numRows( $res );
3787         }
3788
3789         /**
3790          * Compare with another title.
3791          *
3792          * @param $title \type{Title}
3793          * @return \type{\bool} TRUE or FALSE
3794          */
3795         public function equals( Title $title ) {
3796                 // Note: === is necessary for proper matching of number-like titles.
3797                 return $this->getInterwiki() === $title->getInterwiki()
3798                         && $this->getNamespace() == $title->getNamespace()
3799                         && $this->getDBkey() === $title->getDBkey();
3800         }
3801
3802         /**
3803          * Callback for usort() to do title sorts by (namespace, title)
3804          *
3805          * @return Integer: result of string comparison, or namespace comparison
3806          */
3807         public static function compare( $a, $b ) {
3808                 if ( $a->getNamespace() == $b->getNamespace() ) {
3809                         return strcmp( $a->getText(), $b->getText() );
3810                 } else {
3811                         return $a->getNamespace() - $b->getNamespace();
3812                 }
3813         }
3814
3815         /**
3816          * Return a string representation of this title
3817          *
3818          * @return \type{\string} String representation of this title
3819          */
3820         public function __toString() {
3821                 return $this->getPrefixedText();
3822         }
3823
3824         /**
3825          * Check if page exists.  For historical reasons, this function simply
3826          * checks for the existence of the title in the page table, and will
3827          * thus return false for interwiki links, special pages and the like.
3828          * If you want to know if a title can be meaningfully viewed, you should
3829          * probably call the isKnown() method instead.
3830          *
3831          * @return \type{\bool}
3832          */
3833         public function exists() {
3834                 return $this->getArticleId() != 0;
3835         }
3836
3837         /**
3838          * Should links to this title be shown as potentially viewable (i.e. as
3839          * "bluelinks"), even if there's no record by this title in the page
3840          * table?
3841          *
3842          * This function is semi-deprecated for public use, as well as somewhat
3843          * misleadingly named.  You probably just want to call isKnown(), which
3844          * calls this function internally.
3845          *
3846          * (ISSUE: Most of these checks are cheap, but the file existence check
3847          * can potentially be quite expensive.  Including it here fixes a lot of
3848          * existing code, but we might want to add an optional parameter to skip
3849          * it and any other expensive checks.)
3850          *
3851          * @return \type{\bool}
3852          */
3853         public function isAlwaysKnown() {
3854                 if ( $this->mInterwiki != '' ) {
3855                         return true;  // any interwiki link might be viewable, for all we know
3856                 }
3857                 switch( $this->mNamespace ) {
3858                         case NS_MEDIA:
3859                         case NS_FILE:
3860                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3861                         case NS_SPECIAL:
3862                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3863                         case NS_MAIN:
3864                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3865                         case NS_MEDIAWIKI:
3866                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3867                                 // the full l10n of that language to be loaded. That takes much memory and
3868                                 // isn't needed. So we strip the language part away.
3869                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3870                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3871                         default:
3872                                 return false;
3873                 }
3874         }
3875
3876         /**
3877          * Does this title refer to a page that can (or might) be meaningfully
3878          * viewed?  In particular, this function may be used to determine if
3879          * links to the title should be rendered as "bluelinks" (as opposed to
3880          * "redlinks" to non-existent pages).
3881          *
3882          * @return \type{\bool}
3883          */
3884         public function isKnown() {
3885                 return $this->isAlwaysKnown() || $this->exists();
3886         }
3887
3888         /**
3889          * Does this page have source text?
3890          *
3891          * @return Boolean
3892          */
3893         public function hasSourceText() {
3894                 if ( $this->exists() ) {
3895                         return true;
3896                 }
3897
3898                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3899                         // If the page doesn't exist but is a known system message, default
3900                         // message content will be displayed, same for language subpages
3901                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3902                         // causes the full l10n of that language to be loaded. That takes much
3903                         // memory and isn't needed. So we strip the language part away.
3904                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3905                         return (bool)wfMsgWeirdKey( $basename );
3906                 }
3907
3908                 return false;
3909         }
3910
3911         /**
3912          * Is this in a namespace that allows actual pages?
3913          *
3914          * @return \type{\bool}
3915          * @internal note -- uses hardcoded namespace index instead of constants
3916          */
3917         public function canExist() {
3918                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3919         }
3920
3921         /**
3922          * Update page_touched timestamps and send squid purge messages for
3923          * pages linking to this title. May be sent to the job queue depending
3924          * on the number of links. Typically called on create and delete.
3925          */
3926         public function touchLinks() {
3927                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3928                 $u->doUpdate();
3929
3930                 if ( $this->getNamespace() == NS_CATEGORY ) {
3931                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3932                         $u->doUpdate();
3933                 }
3934         }
3935
3936         /**
3937          * Get the last touched timestamp
3938          *
3939          * @param $db DatabaseBase: optional db
3940          * @return \type{\string} Last touched timestamp
3941          */
3942         public function getTouched( $db = null ) {
3943                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3944                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3945                 return $touched;
3946         }
3947
3948         /**
3949          * Get the timestamp when this page was updated since the user last saw it.
3950          *
3951          * @param $user User
3952          * @return Mixed: string/null
3953          */
3954         public function getNotificationTimestamp( $user = null ) {
3955                 global $wgUser, $wgShowUpdatedMarker;
3956                 // Assume current user if none given
3957                 if ( !$user ) {
3958                         $user = $wgUser;
3959                 }
3960                 // Check cache first
3961                 $uid = $user->getId();
3962                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3963                         return $this->mNotificationTimestamp[$uid];
3964                 }
3965                 if ( !$uid || !$wgShowUpdatedMarker ) {
3966                         return $this->mNotificationTimestamp[$uid] = false;
3967                 }
3968                 // Don't cache too much!
3969                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3970                         $this->mNotificationTimestamp = array();
3971                 }
3972                 $dbr = wfGetDB( DB_SLAVE );
3973                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3974                         'wl_notificationtimestamp',
3975                         array( 'wl_namespace' => $this->getNamespace(),
3976                                 'wl_title' => $this->getDBkey(),
3977                                 'wl_user' => $user->getId()
3978                         ),
3979                         __METHOD__
3980                 );
3981                 return $this->mNotificationTimestamp[$uid];
3982         }
3983
3984         /**
3985          * Get the trackback URL for this page
3986          *
3987          * @return \type{\string} Trackback URL
3988          */
3989         public function trackbackURL() {
3990                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3991
3992                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3993                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3994         }
3995
3996         /**
3997          * Get the trackback RDF for this page
3998          *
3999          * @return \type{\string} Trackback RDF
4000          */
4001         public function trackbackRDF() {
4002                 $url = htmlspecialchars( $this->getFullURL() );
4003                 $title = htmlspecialchars( $this->getText() );
4004                 $tburl = $this->trackbackURL();
4005
4006                 // Autodiscovery RDF is placed in comments so HTML validator
4007                 // won't barf. This is a rather icky workaround, but seems
4008                 // frequently used by this kind of RDF thingy.
4009                 //
4010                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4011                 return "<!--
4012 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4013          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4014          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4015 <rdf:Description
4016    rdf:about=\"$url\"
4017    dc:identifier=\"$url\"
4018    dc:title=\"$title\"
4019    trackback:ping=\"$tburl\" />
4020 </rdf:RDF>
4021 -->";
4022         }
4023
4024         /**
4025          * Generate strings used for xml 'id' names in monobook tabs
4026          *
4027          * @param $prepend string defaults to 'nstab-'
4028          * @return \type{\string} XML 'id' name
4029          */
4030         public function getNamespaceKey( $prepend = 'nstab-' ) {
4031                 global $wgContLang;
4032                 // Gets the subject namespace if this title
4033                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4034                 // Checks if cononical namespace name exists for namespace
4035                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4036                         // Uses canonical namespace name
4037                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4038                 } else {
4039                         // Uses text of namespace
4040                         $namespaceKey = $this->getSubjectNsText();
4041                 }
4042                 // Makes namespace key lowercase
4043                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4044                 // Uses main
4045                 if ( $namespaceKey == '' ) {
4046                         $namespaceKey = 'main';
4047                 }
4048                 // Changes file to image for backwards compatibility
4049                 if ( $namespaceKey == 'file' ) {
4050                         $namespaceKey = 'image';
4051                 }
4052                 return $prepend . $namespaceKey;
4053         }
4054
4055         /**
4056          * Returns true if this is a special page.
4057          *
4058          * @return boolean
4059          */
4060         public function isSpecialPage() {
4061                 return $this->getNamespace() == NS_SPECIAL;
4062         }
4063
4064         /**
4065          * Returns true if this title resolves to the named special page
4066          *
4067          * @param $name \type{\string} The special page name
4068          * @return boolean
4069          */
4070         public function isSpecial( $name ) {
4071                 if ( $this->getNamespace() == NS_SPECIAL ) {
4072                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4073                         if ( $name == $thisName ) {
4074                                 return true;
4075                         }
4076                 }
4077                 return false;
4078         }
4079
4080         /**
4081          * If the Title refers to a special page alias which is not the local default,
4082          *
4083          * @return \type{Title} A new Title which points to the local default.
4084          *         Otherwise, returns $this.
4085          */
4086         public function fixSpecialName() {
4087                 if ( $this->getNamespace() == NS_SPECIAL ) {
4088                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4089                         if ( $canonicalName ) {
4090                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4091                                 if ( $localName != $this->mDbkeyform ) {
4092                                         return Title::makeTitle( NS_SPECIAL, $localName );
4093                                 }
4094                         }
4095                 }
4096                 return $this;
4097         }
4098
4099         /**
4100          * Is this Title in a namespace which contains content?
4101          * In other words, is this a content page, for the purposes of calculating
4102          * statistics, etc?
4103          *
4104          * @return Boolean
4105          */
4106         public function isContentPage() {
4107                 return MWNamespace::isContent( $this->getNamespace() );
4108         }
4109
4110         /**
4111          * Get all extant redirects to this Title
4112          *
4113          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4114          *            NULL to consider all namespaces
4115          * @return \type{\arrayof{Title}} Redirects to this title
4116          */
4117         public function getRedirectsHere( $ns = null ) {
4118                 $redirs = array();
4119
4120                 $dbr = wfGetDB( DB_SLAVE );
4121                 $where = array(
4122                         'rd_namespace' => $this->getNamespace(),
4123                         'rd_title' => $this->getDBkey(),
4124                         'rd_from = page_id'
4125                 );
4126                 if ( !is_null( $ns ) ) {
4127                         $where['page_namespace'] = $ns;
4128                 }
4129
4130                 $res = $dbr->select(
4131                         array( 'redirect', 'page' ),
4132                         array( 'page_namespace', 'page_title' ),
4133                         $where,
4134                         __METHOD__
4135                 );
4136
4137                 foreach ( $res as $row ) {
4138                         $redirs[] = self::newFromRow( $row );
4139                 }
4140                 return $redirs;
4141         }
4142
4143         /**
4144          * Check if this Title is a valid redirect target
4145          *
4146          * @return \type{\bool}
4147          */
4148         public function isValidRedirectTarget() {
4149                 global $wgInvalidRedirectTargets;
4150
4151                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4152                 if ( $this->isSpecial( 'Userlogout' ) ) {
4153                         return false;
4154                 }
4155
4156                 foreach ( $wgInvalidRedirectTargets as $target ) {
4157                         if ( $this->isSpecial( $target ) ) {
4158                                 return false;
4159                         }
4160                 }
4161
4162                 return true;
4163         }
4164
4165         /**
4166          * Get a backlink cache object
4167          *
4168          * @return object BacklinkCache
4169          */
4170         function getBacklinkCache() {
4171                 if ( is_null( $this->mBacklinkCache ) ) {
4172                         $this->mBacklinkCache = new BacklinkCache( $this );
4173                 }
4174                 return $this->mBacklinkCache;
4175         }
4176
4177         /**
4178          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4179          * this page.
4180          *
4181          * @return Boolean
4182          */
4183         public function canUseNoindex() {
4184                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4185
4186                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4187                         ? $wgContentNamespaces
4188                         : $wgExemptFromUserRobotsControl;
4189
4190                 return !in_array( $this->mNamespace, $bannedNamespaces );
4191
4192         }
4193
4194         /**
4195          * Returns restriction types for the current Title
4196          *
4197          * @return array applicable restriction types
4198          */
4199         public function getRestrictionTypes() {
4200                 global $wgRestrictionTypes;
4201                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4202
4203                 if ( $this->getNamespace() == NS_FILE ) {
4204                         $types[] = 'upload';
4205                 }
4206
4207                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4208
4209                 return $types;
4210         }
4211
4212         /**
4213          * Returns the raw sort key to be used for categories, with the specified
4214          * prefix.  This will be fed to Language::convertToSortkey() to get a
4215          * binary sortkey that can be used for actual sorting.
4216          *
4217          * @param $prefix string The prefix to be used, specified using
4218          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4219          *   prefix.
4220          * @return string
4221          */
4222         public function getCategorySortkey( $prefix = '' ) {
4223                 $unprefixed = $this->getText();
4224                 if ( $prefix !== '' ) {
4225                         # Separate with a null byte, so the unprefixed part is only used as
4226                         # a tiebreaker when two pages have the exact same prefix -- null
4227                         # sorts before everything else (hopefully).
4228                         return "$prefix\0$unprefixed";
4229                 }
4230                 return $unprefixed;
4231         }
4232 }