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 $wgUser is unable to edit this page because it has been protected
1146          * by $wgNamespaceProtection.
1147          *
1148          * @return \type{\bool}
1149          */
1150         public function isNamespaceProtected() {
1151                 global $wgNamespaceProtection, $wgUser;
1152                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1153                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1154                                 if ( $right != '' && !$wgUser->isAllowed( $right ) ) {
1155                                         return true;
1156                                 }
1157                         }
1158                 }
1159                 return false;
1160         }
1161
1162         /**
1163          * Can $wgUser perform $action on this page?
1164          *
1165          * @param $action \type{\string} action that permission needs to be checked for
1166          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1167          * @return \type{\bool}
1168          */
1169         public function userCan( $action, $doExpensiveQueries = true ) {
1170                 global $wgUser;
1171                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1172         }
1173
1174         /**
1175          * Can $user perform $action on this page?
1176          *
1177          * FIXME: This *does not* check throttles (User::pingLimiter()).
1178          *
1179          * @param $action \type{\string}action that permission needs to be checked for
1180          * @param $user \type{User} user to check
1181          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1182          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1183          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1184          */
1185         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1186                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1187
1188                 // Remove the errors being ignored.
1189                 foreach ( $errors as $index => $error ) {
1190                         $error_key = is_array( $error ) ? $error[0] : $error;
1191
1192                         if ( in_array( $error_key, $ignoreErrors ) ) {
1193                                 unset( $errors[$index] );
1194                         }
1195                 }
1196
1197                 return $errors;
1198         }
1199
1200         /**
1201          * Permissions checks that fail most often, and which are easiest to test.
1202          *
1203          * @param $action String the action to check
1204          * @param $user User user to check
1205          * @param $errors Array list of current errors
1206          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1207          * @param $short Boolean short circuit on first error
1208          *
1209          * @return Array list of errors
1210          */
1211         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1212                 if ( $action == 'create' ) {
1213                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1214                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1215                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1216                         }
1217                 } elseif ( $action == 'move' ) {
1218                         if ( !$user->isAllowed( 'move-rootuserpages' )
1219                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1220                                 // Show user page-specific message only if the user can move other pages
1221                                 $errors[] = array( 'cant-move-user-page' );
1222                         }
1223
1224                         // Check if user is allowed to move files if it's a file
1225                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1226                                 $errors[] = array( 'movenotallowedfile' );
1227                         }
1228
1229                         if ( !$user->isAllowed( 'move' ) ) {
1230                                 // User can't move anything
1231                                 global $wgGroupPermissions;
1232                                 $userCanMove = false;
1233                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1234                                         $userCanMove = $wgGroupPermissions['user']['move'];
1235                                 }
1236                                 $autoconfirmedCanMove = false;
1237                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1238                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1239                                 }
1240                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1241                                         // custom message if logged-in users without any special rights can move
1242                                         $errors[] = array( 'movenologintext' );
1243                                 } else {
1244                                         $errors[] = array( 'movenotallowed' );
1245                                 }
1246                         }
1247                 } elseif ( $action == 'move-target' ) {
1248                         if ( !$user->isAllowed( 'move' ) ) {
1249                                 // User can't move anything
1250                                 $errors[] = array( 'movenotallowed' );
1251                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1252                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1253                                 // Show user page-specific message only if the user can move other pages
1254                                 $errors[] = array( 'cant-move-to-user-page' );
1255                         }
1256                 } elseif ( !$user->isAllowed( $action ) ) {
1257                         // We avoid expensive display logic for quickUserCan's and such
1258                         $groups = false;
1259                         if ( !$short ) {
1260                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1261                                         User::getGroupsWithPermission( $action ) );
1262                         }
1263
1264                         if ( $groups ) {
1265                                 global $wgLang;
1266                                 $return = array(
1267                                         'badaccess-groups',
1268                                         $wgLang->commaList( $groups ),
1269                                         count( $groups )
1270                                 );
1271                         } else {
1272                                 $return = array( 'badaccess-group0' );
1273                         }
1274                         $errors[] = $return;
1275                 }
1276
1277                 return $errors;
1278         }
1279
1280         /**
1281          * Add the resulting error code to the errors array
1282          *
1283          * @param $errors Array list of current errors
1284          * @param $result Mixed result of errors
1285          *
1286          * @return Array list of errors
1287          */
1288         private function resultToError( $errors, $result ) {
1289                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1290                         // A single array representing an error
1291                         $errors[] = $result;
1292                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1293                         // A nested array representing multiple errors
1294                         $errors = array_merge( $errors, $result );
1295                 } else if ( $result !== '' && is_string( $result ) ) {
1296                         // A string representing a message-id
1297                         $errors[] = array( $result );
1298                 } else if ( $result === false ) {
1299                         // a generic "We don't want them to do that"
1300                         $errors[] = array( 'badaccess-group0' );
1301                 }
1302                 return $errors;
1303         }
1304
1305         /**
1306          * Check various permission hooks
1307          *
1308          * @param $action String the action to check
1309          * @param $user User user to check
1310          * @param $errors Array list of current errors
1311          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1312          * @param $short Boolean short circuit on first error
1313          *
1314          * @return Array list of errors
1315          */
1316         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1317                 // Use getUserPermissionsErrors instead
1318                 $result = '';
1319                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1320                         return $result ? array() : array( array( 'badaccess-group0' ) );
1321                 }
1322                 // Check getUserPermissionsErrors hook
1323                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1324                         $errors = $this->resultToError( $errors, $result );
1325                 }
1326                 // Check getUserPermissionsErrorsExpensive hook
1327                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1328                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1329                         $errors = $this->resultToError( $errors, $result );
1330                 }
1331
1332                 return $errors;
1333         }
1334
1335         /**
1336          * Check permissions on special pages & namespaces
1337          *
1338          * @param $action String the action to check
1339          * @param $user User user to check
1340          * @param $errors Array list of current errors
1341          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1342          * @param $short Boolean short circuit on first error
1343          *
1344          * @return Array list of errors
1345          */
1346         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1347                 # Only 'createaccount' and 'execute' can be performed on
1348                 # special pages, which don't actually exist in the DB.
1349                 $specialOKActions = array( 'createaccount', 'execute' );
1350                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1351                         $errors[] = array( 'ns-specialprotected' );
1352                 }
1353
1354                 # Check $wgNamespaceProtection for restricted namespaces
1355                 if ( $this->isNamespaceProtected() ) {
1356                         $ns = $this->mNamespace == NS_MAIN ?
1357                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1358                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1359                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1360                 }
1361
1362                 return $errors;
1363         }
1364
1365         /**
1366          * Check CSS/JS sub-page permissions
1367          *
1368          * @param $action String the action to check
1369          * @param $user User user to check
1370          * @param $errors Array list of current errors
1371          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1372          * @param $short Boolean short circuit on first error
1373          *
1374          * @return Array list of errors
1375          */
1376         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1377                 # Protect css/js subpages of user pages
1378                 # XXX: this might be better using restrictions
1379                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1380                 #      and $this->userCanEditJsSubpage() from working
1381                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1382                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1383                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1384                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1385                                 $errors[] = array( 'customcssjsprotected' );
1386                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1387                                 $errors[] = array( 'customcssjsprotected' );
1388                         }
1389                 }
1390
1391                 return $errors;
1392         }
1393
1394         /**
1395          * Check against page_restrictions table requirements on this
1396          * page. The user must possess all required rights for this
1397          * action.
1398          *
1399          * @param $action String the action to check
1400          * @param $user User user to check
1401          * @param $errors Array list of current errors
1402          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1403          * @param $short Boolean short circuit on first error
1404          *
1405          * @return Array list of errors
1406          */
1407         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1408                 foreach ( $this->getRestrictions( $action ) as $right ) {
1409                         // Backwards compatibility, rewrite sysop -> protect
1410                         if ( $right == 'sysop' ) {
1411                                 $right = 'protect';
1412                         }
1413                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1414                                 // Users with 'editprotected' permission can edit protected pages
1415                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1416                                         // Users with 'editprotected' permission cannot edit protected pages
1417                                         // with cascading option turned on.
1418                                         if ( $this->mCascadeRestriction ) {
1419                                                 $errors[] = array( 'protectedpagetext', $right );
1420                                         }
1421                                 } else {
1422                                         $errors[] = array( 'protectedpagetext', $right );
1423                                 }
1424                         }
1425                 }
1426
1427                 return $errors;
1428         }
1429
1430         /**
1431          * Check restrictions on cascading pages.
1432          *
1433          * @param $action String the action to check
1434          * @param $user User user to check
1435          * @param $errors Array list of current errors
1436          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1437          * @param $short Boolean short circuit on first error
1438          *
1439          * @return Array list of errors
1440          */
1441         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1442                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1443                         # We /could/ use the protection level on the source page, but it's
1444                         # fairly ugly as we have to establish a precedence hierarchy for pages
1445                         # included by multiple cascade-protected pages. So just restrict
1446                         # it to people with 'protect' permission, as they could remove the
1447                         # protection anyway.
1448                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1449                         # Cascading protection depends on more than this page...
1450                         # Several cascading protected pages may include this page...
1451                         # Check each cascading level
1452                         # This is only for protection restrictions, not for all actions
1453                         if ( isset( $restrictions[$action] ) ) {
1454                                 foreach ( $restrictions[$action] as $right ) {
1455                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1456                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1457                                                 $pages = '';
1458                                                 foreach ( $cascadingSources as $page )
1459                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1460                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1461                                         }
1462                                 }
1463                         }
1464                 }
1465
1466                 return $errors;
1467         }
1468
1469         /**
1470          * Check action permissions not already checked in checkQuickPermissions
1471          *
1472          * @param $action String the action to check
1473          * @param $user User user to check
1474          * @param $errors Array list of current errors
1475          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1476          * @param $short Boolean short circuit on first error
1477          *
1478          * @return Array list of errors
1479          */
1480         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1481                 if ( $action == 'protect' ) {
1482                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1483                                 // If they can't edit, they shouldn't protect.
1484                                 $errors[] = array( 'protect-cantedit' );
1485                         }
1486                 } elseif ( $action == 'create' ) {
1487                         $title_protection = $this->getTitleProtection();
1488                         if( $title_protection ) {
1489                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1490                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1491                                 }
1492                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1493                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1494                                 }
1495                         }
1496                 } elseif ( $action == 'move' ) {
1497                         // Check for immobile pages
1498                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1499                                 // Specific message for this case
1500                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1501                         } elseif ( !$this->isMovable() ) {
1502                                 // Less specific message for rarer cases
1503                                 $errors[] = array( 'immobile-page' );
1504                         }
1505                 } elseif ( $action == 'move-target' ) {
1506                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1507                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1508                         } elseif ( !$this->isMovable() ) {
1509                                 $errors[] = array( 'immobile-target-page' );
1510                         }
1511                 }
1512                 return $errors;
1513         }
1514
1515         /**
1516          * Check that the user isn't blocked from editting.
1517          *
1518          * @param $action String the action to check
1519          * @param $user User user to check
1520          * @param $errors Array list of current errors
1521          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1522          * @param $short Boolean short circuit on first error
1523          *
1524          * @return Array list of errors
1525          */
1526         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1527                 if( $short && count( $errors ) > 0 ) {
1528                         return $errors;
1529                 }
1530
1531                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1532
1533                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1534                         $errors[] = array( 'confirmedittext' );
1535                 }
1536
1537                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1538                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1539                         $block = $user->mBlock;
1540
1541                         // This is from OutputPage::blockedPage
1542                         // Copied at r23888 by werdna
1543
1544                         $id = $user->blockedBy();
1545                         $reason = $user->blockedFor();
1546                         if ( $reason == '' ) {
1547                                 $reason = wfMsg( 'blockednoreason' );
1548                         }
1549                         $ip = wfGetIP();
1550
1551                         if ( is_numeric( $id ) ) {
1552                                 $name = User::whoIs( $id );
1553                         } else {
1554                                 $name = $id;
1555                         }
1556
1557                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1558                         $blockid = $block->mId;
1559                         $blockExpiry = $user->mBlock->mExpiry;
1560                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1561                         if ( $blockExpiry == 'infinity' ) {
1562                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1563                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1564
1565                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1566                                         if ( !strpos( $option, ':' ) )
1567                                                 continue;
1568
1569                                         list( $show, $value ) = explode( ':', $option );
1570
1571                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1572                                                 $blockExpiry = $show;
1573                                                 break;
1574                                         }
1575                                 }
1576                         } else {
1577                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1578                         }
1579
1580                         $intended = $user->mBlock->mAddress;
1581
1582                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1583                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1584                 }
1585
1586                 return $errors;
1587         }
1588
1589         /**
1590          * Can $user perform $action on this page? This is an internal function,
1591          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1592          * checks on wfReadOnly() and blocks)
1593          *
1594          * @param $action \type{\string} action that permission needs to be checked for
1595          * @param $user \type{User} user to check
1596          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1597          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1598          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1599          */
1600         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1601                 wfProfileIn( __METHOD__ );
1602
1603                 $errors = array();
1604                 $checks = array(
1605                         'checkQuickPermissions',
1606                         'checkPermissionHooks',
1607                         'checkSpecialsAndNSPermissions',
1608                         'checkCSSandJSPermissions',
1609                         'checkPageRestrictions',
1610                         'checkCascadingSourcesRestrictions',
1611                         'checkActionPermissions',
1612                         'checkUserBlock'
1613                 );
1614
1615                 while( count( $checks ) > 0 &&
1616                            !( $short && count( $errors ) > 0 ) ) {
1617                         $method = array_shift( $checks );
1618                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1619                 }
1620
1621                 wfProfileOut( __METHOD__ );
1622                 return $errors;
1623         }
1624
1625         /**
1626          * Is this title subject to title protection?
1627          *
1628          * @return \type{\mixed} An associative array representing any existent title
1629          *   protection, or false if there's none.
1630          */
1631         private function getTitleProtection() {
1632                 // Can't protect pages in special namespaces
1633                 if ( $this->getNamespace() < 0 ) {
1634                         return false;
1635                 }
1636
1637                 // Can't protect pages that exist.
1638                 if ( $this->exists() ) {
1639                         return false;
1640                 }
1641
1642                 if ( !isset( $this->mTitleProtection ) ) {
1643                         $dbr = wfGetDB( DB_SLAVE );
1644                         $res = $dbr->select( 'protected_titles', '*',
1645                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1646                                 __METHOD__ );
1647
1648                         // fetchRow returns false if there are no rows.
1649                         $this->mTitleProtection = $dbr->fetchRow( $res );
1650                 }
1651                 return $this->mTitleProtection;
1652         }
1653
1654         private function invalidateTitleProtectionCache() {
1655                 unset( $this->mTitleProtection );
1656         }
1657
1658         /**
1659          * Update the title protection status
1660          *
1661          * @param $create_perm \type{\string} Permission required for creation
1662          * @param $reason \type{\string} Reason for protection
1663          * @param $expiry \type{\string} Expiry timestamp
1664          * @return boolean true
1665          */
1666         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1667                 global $wgUser, $wgContLang;
1668
1669                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1670                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1671                         // No change
1672                         return true;
1673                 }
1674
1675                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1676
1677                 $dbw = wfGetDB( DB_MASTER );
1678
1679                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1680
1681                 $expiry_description = '';
1682                 if ( $encodedExpiry != 'infinity' ) {
1683                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1684                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1685                 } else {
1686                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1687                 }
1688
1689                 # Update protection table
1690                 if ( $create_perm != '' ) {
1691                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1692                                 array(
1693                                         'pt_namespace' => $namespace,
1694                                         'pt_title' => $title,
1695                                         'pt_create_perm' => $create_perm,
1696                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1697                                         'pt_expiry' => $encodedExpiry,
1698                                         'pt_user' => $wgUser->getId(),
1699                                         'pt_reason' => $reason,
1700                                 ), __METHOD__
1701                         );
1702                 } else {
1703                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1704                                 'pt_title' => $title ), __METHOD__ );
1705                 }
1706                 $this->invalidateTitleProtectionCache();
1707
1708                 # Update the protection log
1709                 if ( $dbw->affectedRows() ) {
1710                         $log = new LogPage( 'protect' );
1711
1712                         if ( $create_perm ) {
1713                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1714                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1715                         } else {
1716                                 $log->addEntry( 'unprotect', $this, $reason );
1717                         }
1718                 }
1719
1720                 return true;
1721         }
1722
1723         /**
1724          * Remove any title protection due to page existing
1725          */
1726         public function deleteTitleProtection() {
1727                 $dbw = wfGetDB( DB_MASTER );
1728
1729                 $dbw->delete(
1730                         'protected_titles',
1731                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1732                         __METHOD__
1733                 );
1734                 $this->invalidateTitleProtectionCache();
1735         }
1736
1737         /**
1738          * Would anybody with sufficient privileges be able to move this page?
1739          * Some pages just aren't movable.
1740          *
1741          * @return \type{\bool} TRUE or FALSE
1742          */
1743         public function isMovable() {
1744                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1745         }
1746
1747         /**
1748          * Can $wgUser read this page?
1749          *
1750          * @return \type{\bool}
1751          * @todo fold these checks into userCan()
1752          */
1753         public function userCanRead() {
1754                 global $wgUser, $wgGroupPermissions;
1755
1756                 static $useShortcut = null;
1757
1758                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1759                 if ( is_null( $useShortcut ) ) {
1760                         global $wgRevokePermissions;
1761                         $useShortcut = true;
1762                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1763                                 # Not a public wiki, so no shortcut
1764                                 $useShortcut = false;
1765                         } elseif ( !empty( $wgRevokePermissions ) ) {
1766                                 /*
1767                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1768                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1769                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1770                                  * reading is allowed.
1771                                  */
1772                                 foreach ( $wgRevokePermissions as $perms ) {
1773                                         if ( !empty( $perms['read'] ) ) {
1774                                                 # We might be removing the read right from the user, so no shortcut
1775                                                 $useShortcut = false;
1776                                                 break;
1777                                         }
1778                                 }
1779                         }
1780                 }
1781
1782                 $result = null;
1783                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1784                 if ( $result !== null ) {
1785                         return $result;
1786                 }
1787
1788                 # Shortcut for public wikis, allows skipping quite a bit of code
1789                 if ( $useShortcut ) {
1790                         return true;
1791                 }
1792
1793                 if ( $wgUser->isAllowed( 'read' ) ) {
1794                         return true;
1795                 } else {
1796                         global $wgWhitelistRead;
1797
1798                         /**
1799                          * Always grant access to the login page.
1800                          * Even anons need to be able to log in.
1801                         */
1802                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1803                                 return true;
1804                         }
1805
1806                         /**
1807                          * Bail out if there isn't whitelist
1808                          */
1809                         if ( !is_array( $wgWhitelistRead ) ) {
1810                                 return false;
1811                         }
1812
1813                         /**
1814                          * Check for explicit whitelisting
1815                          */
1816                         $name = $this->getPrefixedText();
1817                         $dbName = $this->getPrefixedDBKey();
1818                         // Check with and without underscores
1819                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1820                                 return true;
1821
1822                         /**
1823                          * Old settings might have the title prefixed with
1824                          * a colon for main-namespace pages
1825                          */
1826                         if ( $this->getNamespace() == NS_MAIN ) {
1827                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1828                                         return true;
1829                                 }
1830                         }
1831
1832                         /**
1833                          * If it's a special page, ditch the subpage bit
1834                          * and check again
1835                          */
1836                         if ( $this->getNamespace() == NS_SPECIAL ) {
1837                                 $name = $this->getDBkey();
1838                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1839                                 if ( $name === false ) {
1840                                         # Invalid special page, but we show standard login required message
1841                                         return false;
1842                                 }
1843
1844                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1845                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1846                                         return true;
1847                                 }
1848                         }
1849
1850                 }
1851                 return false;
1852         }
1853
1854         /**
1855          * Is this a talk page of some sort?
1856          *
1857          * @return \type{\bool}
1858          */
1859         public function isTalkPage() {
1860                 return MWNamespace::isTalk( $this->getNamespace() );
1861         }
1862
1863         /**
1864          * Is this a subpage?
1865          *
1866          * @return \type{\bool}
1867          */
1868         public function isSubpage() {
1869                 return MWNamespace::hasSubpages( $this->mNamespace )
1870                         ? strpos( $this->getText(), '/' ) !== false
1871                         : false;
1872         }
1873
1874         /**
1875          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1876          *
1877          * @return \type{\bool}
1878          */
1879         public function hasSubpages() {
1880                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1881                         # Duh
1882                         return false;
1883                 }
1884
1885                 # We dynamically add a member variable for the purpose of this method
1886                 # alone to cache the result.  There's no point in having it hanging
1887                 # around uninitialized in every Title object; therefore we only add it
1888                 # if needed and don't declare it statically.
1889                 if ( isset( $this->mHasSubpages ) ) {
1890                         return $this->mHasSubpages;
1891                 }
1892
1893                 $subpages = $this->getSubpages( 1 );
1894                 if ( $subpages instanceof TitleArray ) {
1895                         return $this->mHasSubpages = (bool)$subpages->count();
1896                 }
1897                 return $this->mHasSubpages = false;
1898         }
1899
1900         /**
1901          * Get all subpages of this page.
1902          *
1903          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1904          * @return mixed TitleArray, or empty array if this page's namespace
1905          *  doesn't allow subpages
1906          */
1907         public function getSubpages( $limit = -1 ) {
1908                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1909                         return array();
1910                 }
1911
1912                 $dbr = wfGetDB( DB_SLAVE );
1913                 $conds['page_namespace'] = $this->getNamespace();
1914                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1915                 $options = array();
1916                 if ( $limit > -1 ) {
1917                         $options['LIMIT'] = $limit;
1918                 }
1919                 return $this->mSubpages = TitleArray::newFromResult(
1920                         $dbr->select( 'page',
1921                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1922                                 $conds,
1923                                 __METHOD__,
1924                                 $options
1925                         )
1926                 );
1927         }
1928
1929         /**
1930          * Could this page contain custom CSS or JavaScript, based
1931          * on the title?
1932          *
1933          * @return \type{\bool}
1934          */
1935         public function isCssOrJsPage() {
1936                 return $this->mNamespace == NS_MEDIAWIKI
1937                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1938         }
1939
1940         /**
1941          * Is this a .css or .js subpage of a user page?
1942          * @return \type{\bool}
1943          */
1944         public function isCssJsSubpage() {
1945                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1946         }
1947
1948         /**
1949          * Is this a *valid* .css or .js subpage of a user page?
1950          *
1951          * @return \type{\bool}
1952          * @deprecated
1953          */
1954         public function isValidCssJsSubpage() {
1955                 return $this->isCssJsSubpage();
1956         }
1957
1958         /**
1959          * Trim down a .css or .js subpage title to get the corresponding skin name
1960          *
1961          * @return string containing skin name from .css or .js subpage title
1962          */
1963         public function getSkinFromCssJsSubpage() {
1964                 $subpage = explode( '/', $this->mTextform );
1965                 $subpage = $subpage[ count( $subpage ) - 1 ];
1966                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1967         }
1968
1969         /**
1970          * Is this a .css subpage of a user page?
1971          *
1972          * @return \type{\bool}
1973          */
1974         public function isCssSubpage() {
1975                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1976         }
1977
1978         /**
1979          * Is this a .js subpage of a user page?
1980          *
1981          * @return \type{\bool}
1982          */
1983         public function isJsSubpage() {
1984                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1985         }
1986
1987         /**
1988          * Protect css subpages of user pages: can $wgUser edit
1989          * this page?
1990          *
1991          * @return \type{\bool}
1992          * @todo XXX: this might be better using restrictions
1993          */
1994         public function userCanEditCssSubpage() {
1995                 global $wgUser;
1996                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1997                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1998         }
1999
2000         /**
2001          * Protect js subpages of user pages: can $wgUser edit
2002          * this page?
2003          *
2004          * @return \type{\bool}
2005          * @todo XXX: this might be better using restrictions
2006          */
2007         public function userCanEditJsSubpage() {
2008                 global $wgUser;
2009                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2010                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2011         }
2012
2013         /**
2014          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2015          *
2016          * @return \type{\bool} If the page is subject to cascading restrictions.
2017          */
2018         public function isCascadeProtected() {
2019                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2020                 return ( $sources > 0 );
2021         }
2022
2023         /**
2024          * Cascading protection: Get the source of any cascading restrictions on this page.
2025          *
2026          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
2027          *        that the restrictions have come from.
2028          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
2029          *         objects of the pages from which cascading restrictions have come,
2030          *         false for none, or true if such restrictions exist, but $getPages was not set.
2031          *         The restriction array is an array of each type, each of which contains a
2032          *         array of unique groups.
2033          */
2034         public function getCascadeProtectionSources( $getPages = true ) {
2035                 $pagerestrictions = array();
2036
2037                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2038                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2039                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2040                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2041                 }
2042
2043                 wfProfileIn( __METHOD__ );
2044
2045                 $dbr = wfGetDB( DB_SLAVE );
2046
2047                 if ( $this->getNamespace() == NS_FILE ) {
2048                         $tables = array( 'imagelinks', 'page_restrictions' );
2049                         $where_clauses = array(
2050                                 'il_to' => $this->getDBkey(),
2051                                 'il_from=pr_page',
2052                                 'pr_cascade' => 1
2053                         );
2054                 } else {
2055                         $tables = array( 'templatelinks', 'page_restrictions' );
2056                         $where_clauses = array(
2057                                 'tl_namespace' => $this->getNamespace(),
2058                                 'tl_title' => $this->getDBkey(),
2059                                 'tl_from=pr_page',
2060                                 'pr_cascade' => 1
2061                         );
2062                 }
2063
2064                 if ( $getPages ) {
2065                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2066                                                    'pr_expiry', 'pr_type', 'pr_level' );
2067                         $where_clauses[] = 'page_id=pr_page';
2068                         $tables[] = 'page';
2069                 } else {
2070                         $cols = array( 'pr_expiry' );
2071                 }
2072
2073                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2074
2075                 $sources = $getPages ? array() : false;
2076                 $now = wfTimestampNow();
2077                 $purgeExpired = false;
2078
2079                 foreach ( $res as $row ) {
2080                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2081                         if ( $expiry > $now ) {
2082                                 if ( $getPages ) {
2083                                         $page_id = $row->pr_page;
2084                                         $page_ns = $row->page_namespace;
2085                                         $page_title = $row->page_title;
2086                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2087                                         # Add groups needed for each restriction type if its not already there
2088                                         # Make sure this restriction type still exists
2089
2090                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2091                                                 $pagerestrictions[$row->pr_type] = array();
2092                                         }
2093
2094                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2095                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2096                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2097                                         }
2098                                 } else {
2099                                         $sources = true;
2100                                 }
2101                         } else {
2102                                 // Trigger lazy purge of expired restrictions from the db
2103                                 $purgeExpired = true;
2104                         }
2105                 }
2106                 if ( $purgeExpired ) {
2107                         Title::purgeExpiredRestrictions();
2108                         $this->invalidateTitleProtectionCache();
2109                 }
2110
2111                 wfProfileOut( __METHOD__ );
2112
2113                 if ( $getPages ) {
2114                         $this->mCascadeSources = $sources;
2115                         $this->mCascadingRestrictions = $pagerestrictions;
2116                 } else {
2117                         $this->mHasCascadingRestrictions = $sources;
2118                 }
2119
2120                 return array( $sources, $pagerestrictions );
2121         }
2122
2123         /**
2124          * Returns cascading restrictions for the current article
2125          *
2126          * @return Boolean
2127          */
2128         function areRestrictionsCascading() {
2129                 if ( !$this->mRestrictionsLoaded ) {
2130                         $this->loadRestrictions();
2131                 }
2132
2133                 return $this->mCascadeRestriction;
2134         }
2135
2136         /**
2137          * Loads a string into mRestrictions array
2138          *
2139          * @param $res \type{Resource} restrictions as an SQL result.
2140          * @param $oldFashionedRestrictions string comma-separated list of page
2141          *        restrictions from page table (pre 1.10)
2142          */
2143         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2144                 $rows = array();
2145
2146                 foreach ( $res as $row ) {
2147                         $rows[] = $row;
2148                 }
2149
2150                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2151         }
2152
2153         /**
2154          * Compiles list of active page restrictions from both page table (pre 1.10)
2155          * and page_restrictions table
2156          *
2157          * @param $rows array of db result objects
2158          * @param $oldFashionedRestrictions string comma-separated list of page
2159          *        restrictions from page table (pre 1.10)
2160          */
2161         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2162                 $dbr = wfGetDB( DB_SLAVE );
2163
2164                 $restrictionTypes = $this->getRestrictionTypes();
2165
2166                 foreach ( $restrictionTypes as $type ) {
2167                         $this->mRestrictions[$type] = array();
2168                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2169                 }
2170
2171                 $this->mCascadeRestriction = false;
2172
2173                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2174
2175                 if ( $oldFashionedRestrictions === null ) {
2176                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2177                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2178                 }
2179
2180                 if ( $oldFashionedRestrictions != '' ) {
2181
2182                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2183                                 $temp = explode( '=', trim( $restrict ) );
2184                                 if ( count( $temp ) == 1 ) {
2185                                         // old old format should be treated as edit/move restriction
2186                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2187                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2188                                 } else {
2189                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2190                                 }
2191                         }
2192
2193                         $this->mOldRestrictions = true;
2194
2195                 }
2196
2197                 if ( count( $rows ) ) {
2198                         # Current system - load second to make them override.
2199                         $now = wfTimestampNow();
2200                         $purgeExpired = false;
2201
2202                         foreach ( $rows as $row ) {
2203                                 # Cycle through all the restrictions.
2204
2205                                 // Don't take care of restrictions types that aren't allowed
2206
2207                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2208                                         continue;
2209
2210                                 // This code should be refactored, now that it's being used more generally,
2211                                 // But I don't really see any harm in leaving it in Block for now -werdna
2212                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2213
2214                                 // Only apply the restrictions if they haven't expired!
2215                                 if ( !$expiry || $expiry > $now ) {
2216                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2217                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2218
2219                                         $this->mCascadeRestriction |= $row->pr_cascade;
2220                                 } else {
2221                                         // Trigger a lazy purge of expired restrictions
2222                                         $purgeExpired = true;
2223                                 }
2224                         }
2225
2226                         if ( $purgeExpired ) {
2227                                 Title::purgeExpiredRestrictions();
2228                                 $this->invalidateTitleProtectionCache();
2229                         }
2230                 }
2231
2232                 $this->mRestrictionsLoaded = true;
2233         }
2234
2235         /**
2236          * Load restrictions from the page_restrictions table
2237          *
2238          * @param $oldFashionedRestrictions string comma-separated list of page
2239          *        restrictions from page table (pre 1.10)
2240          */
2241         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2242                 if ( !$this->mRestrictionsLoaded ) {
2243                         if ( $this->exists() ) {
2244                                 $dbr = wfGetDB( DB_SLAVE );
2245
2246                                 $res = $dbr->select( 'page_restrictions', '*',
2247                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2248
2249                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2250                         } else {
2251                                 $title_protection = $this->getTitleProtection();
2252
2253                                 if ( $title_protection ) {
2254                                         $now = wfTimestampNow();
2255                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2256
2257                                         if ( !$expiry || $expiry > $now ) {
2258                                                 // Apply the restrictions
2259                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2260                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2261                                         } else { // Get rid of the old restrictions
2262                                                 Title::purgeExpiredRestrictions();
2263                                                 $this->invalidateTitleProtectionCache();
2264                                         }
2265                                 } else {
2266                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2267                                 }
2268                                 $this->mRestrictionsLoaded = true;
2269                         }
2270                 }
2271         }
2272
2273         /**
2274          * Purge expired restrictions from the page_restrictions table
2275          */
2276         static function purgeExpiredRestrictions() {
2277                 $dbw = wfGetDB( DB_MASTER );
2278                 $dbw->delete(
2279                         'page_restrictions',
2280                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2281                         __METHOD__
2282                 );
2283
2284                 $dbw->delete(
2285                         'protected_titles',
2286                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2287                         __METHOD__
2288                 );
2289         }
2290
2291         /**
2292          * Accessor/initialisation for mRestrictions
2293          *
2294          * @param $action \type{\string} action that permission needs to be checked for
2295          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2296          */
2297         public function getRestrictions( $action ) {
2298                 if ( !$this->mRestrictionsLoaded ) {
2299                         $this->loadRestrictions();
2300                 }
2301                 return isset( $this->mRestrictions[$action] )
2302                                 ? $this->mRestrictions[$action]
2303                                 : array();
2304         }
2305
2306         /**
2307          * Get the expiry time for the restriction against a given action
2308          *
2309          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2310          *      or not protected at all, or false if the action is not recognised.
2311          */
2312         public function getRestrictionExpiry( $action ) {
2313                 if ( !$this->mRestrictionsLoaded ) {
2314                         $this->loadRestrictions();
2315                 }
2316                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2317         }
2318
2319         /**
2320          * Is there a version of this page in the deletion archive?
2321          *
2322          * @return \type{\int} the number of archived revisions
2323          */
2324         public function isDeleted() {
2325                 if ( $this->getNamespace() < 0 ) {
2326                         $n = 0;
2327                 } else {
2328                         $dbr = wfGetDB( DB_SLAVE );
2329                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2330                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2331                                 __METHOD__
2332                         );
2333                         if ( $this->getNamespace() == NS_FILE ) {
2334                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2335                                         array( 'fa_name' => $this->getDBkey() ),
2336                                         __METHOD__
2337                                 );
2338                         }
2339                 }
2340                 return (int)$n;
2341         }
2342
2343         /**
2344          * Is there a version of this page in the deletion archive?
2345          *
2346          * @return Boolean
2347          */
2348         public function isDeletedQuick() {
2349                 if ( $this->getNamespace() < 0 ) {
2350                         return false;
2351                 }
2352                 $dbr = wfGetDB( DB_SLAVE );
2353                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2354                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2355                         __METHOD__
2356                 );
2357                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2358                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2359                                 array( 'fa_name' => $this->getDBkey() ),
2360                                 __METHOD__
2361                         );
2362                 }
2363                 return $deleted;
2364         }
2365
2366         /**
2367          * Get the article ID for this Title from the link cache,
2368          * adding it if necessary
2369          *
2370          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2371          *  for update
2372          * @return \type{\int} the ID
2373          */
2374         public function getArticleID( $flags = 0 ) {
2375                 if ( $this->getNamespace() < 0 ) {
2376                         return $this->mArticleID = 0;
2377                 }
2378                 $linkCache = LinkCache::singleton();
2379                 if ( $flags & self::GAID_FOR_UPDATE ) {
2380                         $oldUpdate = $linkCache->forUpdate( true );
2381                         $linkCache->clearLink( $this );
2382                         $this->mArticleID = $linkCache->addLinkObj( $this );
2383                         $linkCache->forUpdate( $oldUpdate );
2384                 } else {
2385                         if ( -1 == $this->mArticleID ) {
2386                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2387                         }
2388                 }
2389                 return $this->mArticleID;
2390         }
2391
2392         /**
2393          * Is this an article that is a redirect page?
2394          * Uses link cache, adding it if necessary
2395          *
2396          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2397          * @return \type{\bool}
2398          */
2399         public function isRedirect( $flags = 0 ) {
2400                 if ( !is_null( $this->mRedirect ) ) {
2401                         return $this->mRedirect;
2402                 }
2403                 # Calling getArticleID() loads the field from cache as needed
2404                 if ( !$this->getArticleID( $flags ) ) {
2405                         return $this->mRedirect = false;
2406                 }
2407                 $linkCache = LinkCache::singleton();
2408                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2409
2410                 return $this->mRedirect;
2411         }
2412
2413         /**
2414          * What is the length of this page?
2415          * Uses link cache, adding it if necessary
2416          *
2417          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2418          * @return \type{\bool}
2419          */
2420         public function getLength( $flags = 0 ) {
2421                 if ( $this->mLength != -1 ) {
2422                         return $this->mLength;
2423                 }
2424                 # Calling getArticleID() loads the field from cache as needed
2425                 if ( !$this->getArticleID( $flags ) ) {
2426                         return $this->mLength = 0;
2427                 }
2428                 $linkCache = LinkCache::singleton();
2429                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2430
2431                 return $this->mLength;
2432         }
2433
2434         /**
2435          * What is the page_latest field for this page?
2436          *
2437          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2438          * @return \type{\int} or 0 if the page doesn't exist
2439          */
2440         public function getLatestRevID( $flags = 0 ) {
2441                 if ( $this->mLatestID !== false ) {
2442                         return intval( $this->mLatestID );
2443                 }
2444                 # Calling getArticleID() loads the field from cache as needed
2445                 if ( !$this->getArticleID( $flags ) ) {
2446                         return $this->mLatestID = 0;
2447                 }
2448                 $linkCache = LinkCache::singleton();
2449                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2450
2451                 return $this->mLatestID;
2452         }
2453
2454         /**
2455          * This clears some fields in this object, and clears any associated
2456          * keys in the "bad links" section of the link cache.
2457          *
2458          * - This is called from Article::insertNewArticle() to allow
2459          * loading of the new page_id. It's also called from
2460          * Article::doDeleteArticle()
2461          *
2462          * @param $newid \type{\int} the new Article ID
2463          */
2464         public function resetArticleID( $newid ) {
2465                 $linkCache = LinkCache::singleton();
2466                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2467
2468                 if ( $newid === false ) {
2469                         $this->mArticleID = -1;
2470                 } else {
2471                         $this->mArticleID = intval( $newid );
2472                 }
2473                 $this->mRestrictionsLoaded = false;
2474                 $this->mRestrictions = array();
2475                 $this->mRedirect = null;
2476                 $this->mLength = -1;
2477                 $this->mLatestID = false;
2478         }
2479
2480         /**
2481          * Updates page_touched for this page; called from LinksUpdate.php
2482          *
2483          * @return \type{\bool} true if the update succeded
2484          */
2485         public function invalidateCache() {
2486                 if ( wfReadOnly() ) {
2487                         return;
2488                 }
2489                 $dbw = wfGetDB( DB_MASTER );
2490                 $success = $dbw->update(
2491                         'page',
2492                         array( 'page_touched' => $dbw->timestamp() ),
2493                         $this->pageCond(),
2494                         __METHOD__
2495                 );
2496                 HTMLFileCache::clearFileCache( $this );
2497                 return $success;
2498         }
2499
2500         /**
2501          * Prefix some arbitrary text with the namespace or interwiki prefix
2502          * of this object
2503          *
2504          * @param $name \type{\string} the text
2505          * @return \type{\string} the prefixed text
2506          * @private
2507          */
2508         /* private */ function prefix( $name ) {
2509                 $p = '';
2510                 if ( $this->mInterwiki != '' ) {
2511                         $p = $this->mInterwiki . ':';
2512                 }
2513                 if ( 0 != $this->mNamespace ) {
2514                         $p .= $this->getNsText() . ':';
2515                 }
2516                 return $p . $name;
2517         }
2518
2519         /**
2520          * Returns a simple regex that will match on characters and sequences invalid in titles.
2521          * Note that this doesn't pick up many things that could be wrong with titles, but that
2522          * replacing this regex with something valid will make many titles valid.
2523          *
2524          * @return string regex string
2525          */
2526         static function getTitleInvalidRegex() {
2527                 static $rxTc = false;
2528                 if ( !$rxTc ) {
2529                         # Matching titles will be held as illegal.
2530                         $rxTc = '/' .
2531                                 # Any character not allowed is forbidden...
2532                                 '[^' . Title::legalChars() . ']' .
2533                                 # URL percent encoding sequences interfere with the ability
2534                                 # to round-trip titles -- you can't link to them consistently.
2535                                 '|%[0-9A-Fa-f]{2}' .
2536                                 # XML/HTML character references produce similar issues.
2537                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2538                                 '|&#[0-9]+;' .
2539                                 '|&#x[0-9A-Fa-f]+;' .
2540                                 '/S';
2541                 }
2542
2543                 return $rxTc;
2544         }
2545
2546         /**
2547          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2548          *
2549          * @param $text string containing title to capitalize
2550          * @param $ns int namespace index, defaults to NS_MAIN
2551          * @return String containing capitalized title
2552          */
2553         public static function capitalize( $text, $ns = NS_MAIN ) {
2554                 global $wgContLang;
2555
2556                 if ( MWNamespace::isCapitalized( $ns ) ) {
2557                         return $wgContLang->ucfirst( $text );
2558                 } else {
2559                         return $text;
2560                 }
2561         }
2562
2563         /**
2564          * Secure and split - main initialisation function for this object
2565          *
2566          * Assumes that mDbkeyform has been set, and is urldecoded
2567          * and uses underscores, but not otherwise munged.  This function
2568          * removes illegal characters, splits off the interwiki and
2569          * namespace prefixes, sets the other forms, and canonicalizes
2570          * everything.
2571          *
2572          * @return \type{\bool} true on success
2573          */
2574         private function secureAndSplit() {
2575                 global $wgContLang, $wgLocalInterwiki;
2576
2577                 # Initialisation
2578                 $rxTc = self::getTitleInvalidRegex();
2579
2580                 $this->mInterwiki = $this->mFragment = '';
2581                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2582
2583                 $dbkey = $this->mDbkeyform;
2584
2585                 # Strip Unicode bidi override characters.
2586                 # Sometimes they slip into cut-n-pasted page titles, where the
2587                 # override chars get included in list displays.
2588                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2589
2590                 # Clean up whitespace
2591                 # Note: use of the /u option on preg_replace here will cause
2592                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2593                 # conveniently disabling them.
2594                 #
2595                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2596                 $dbkey = trim( $dbkey, '_' );
2597
2598                 if ( $dbkey == '' ) {
2599                         return false;
2600                 }
2601
2602                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2603                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2604                         return false;
2605                 }
2606
2607                 $this->mDbkeyform = $dbkey;
2608
2609                 # Initial colon indicates main namespace rather than specified default
2610                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2611                 if ( ':' == $dbkey { 0 } ) {
2612                         $this->mNamespace = NS_MAIN;
2613                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2614                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2615                 }
2616
2617                 # Namespace or interwiki prefix
2618                 $firstPass = true;
2619                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2620                 do {
2621                         $m = array();
2622                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2623                                 $p = $m[1];
2624                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2625                                         # Ordinary namespace
2626                                         $dbkey = $m[2];
2627                                         $this->mNamespace = $ns;
2628                                         # For Talk:X pages, check if X has a "namespace" prefix
2629                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2630                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2631                                                         return false; # Disallow Talk:File:x type titles...
2632                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2633                                                         return false; # Disallow Talk:Interwiki:x type titles...
2634                                                 }
2635                                         }
2636                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2637                                         if ( !$firstPass ) {
2638                                                 # Can't make a local interwiki link to an interwiki link.
2639                                                 # That's just crazy!
2640                                                 return false;
2641                                         }
2642
2643                                         # Interwiki link
2644                                         $dbkey = $m[2];
2645                                         $this->mInterwiki = $wgContLang->lc( $p );
2646
2647                                         # Redundant interwiki prefix to the local wiki
2648                                         if ( $wgLocalInterwiki !== false
2649                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2650                                         {
2651                                                 if ( $dbkey == '' ) {
2652                                                         # Can't have an empty self-link
2653                                                         return false;
2654                                                 }
2655                                                 $this->mInterwiki = '';
2656                                                 $firstPass = false;
2657                                                 # Do another namespace split...
2658                                                 continue;
2659                                         }
2660
2661                                         # If there's an initial colon after the interwiki, that also
2662                                         # resets the default namespace
2663                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2664                                                 $this->mNamespace = NS_MAIN;
2665                                                 $dbkey = substr( $dbkey, 1 );
2666                                         }
2667                                 }
2668                                 # If there's no recognized interwiki or namespace,
2669                                 # then let the colon expression be part of the title.
2670                         }
2671                         break;
2672                 } while ( true );
2673
2674                 # We already know that some pages won't be in the database!
2675                 #
2676                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2677                         $this->mArticleID = 0;
2678                 }
2679                 $fragment = strstr( $dbkey, '#' );
2680                 if ( false !== $fragment ) {
2681                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2682                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2683                         # remove whitespace again: prevents "Foo_bar_#"
2684                         # becoming "Foo_bar_"
2685                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2686                 }
2687
2688                 # Reject illegal characters.
2689                 #
2690                 if ( preg_match( $rxTc, $dbkey ) ) {
2691                         return false;
2692                 }
2693
2694                 /**
2695                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2696                  * reachable due to the way web browsers deal with 'relative' URLs.
2697                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2698                  */
2699                 if ( strpos( $dbkey, '.' ) !== false &&
2700                      ( $dbkey === '.' || $dbkey === '..' ||
2701                        strpos( $dbkey, './' ) === 0  ||
2702                        strpos( $dbkey, '../' ) === 0 ||
2703                        strpos( $dbkey, '/./' ) !== false ||
2704                        strpos( $dbkey, '/../' ) !== false  ||
2705                        substr( $dbkey, -2 ) == '/.' ||
2706                        substr( $dbkey, -3 ) == '/..' ) )
2707                 {
2708                         return false;
2709                 }
2710
2711                 /**
2712                  * Magic tilde sequences? Nu-uh!
2713                  */
2714                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2715                         return false;
2716                 }
2717
2718                 /**
2719                  * Limit the size of titles to 255 bytes.
2720                  * This is typically the size of the underlying database field.
2721                  * We make an exception for special pages, which don't need to be stored
2722                  * in the database, and may edge over 255 bytes due to subpage syntax
2723                  * for long titles, e.g. [[Special:Block/Long name]]
2724                  */
2725                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2726                   strlen( $dbkey ) > 512 )
2727                 {
2728                         return false;
2729                 }
2730
2731                 /**
2732                  * Normally, all wiki links are forced to have
2733                  * an initial capital letter so [[foo]] and [[Foo]]
2734                  * point to the same place.
2735                  *
2736                  * Don't force it for interwikis, since the other
2737                  * site might be case-sensitive.
2738                  */
2739                 $this->mUserCaseDBKey = $dbkey;
2740                 if ( $this->mInterwiki == '' ) {
2741                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2742                 }
2743
2744                 /**
2745                  * Can't make a link to a namespace alone...
2746                  * "empty" local links can only be self-links
2747                  * with a fragment identifier.
2748                  */
2749                 if ( $dbkey == '' &&
2750                         $this->mInterwiki == '' &&
2751                         $this->mNamespace != NS_MAIN ) {
2752                         return false;
2753                 }
2754                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2755                 // IP names are not allowed for accounts, and can only be referring to
2756                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2757                 // there are numerous ways to present the same IP. Having sp:contribs scan
2758                 // them all is silly and having some show the edits and others not is
2759                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2760                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2761                         IP::sanitizeIP( $dbkey ) : $dbkey;
2762                 // Any remaining initial :s are illegal.
2763                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2764                         return false;
2765                 }
2766
2767                 # Fill fields
2768                 $this->mDbkeyform = $dbkey;
2769                 $this->mUrlform = wfUrlencode( $dbkey );
2770
2771                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2772
2773                 return true;
2774         }
2775
2776         /**
2777          * Set the fragment for this title. Removes the first character from the
2778          * specified fragment before setting, so it assumes you're passing it with
2779          * an initial "#".
2780          *
2781          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2782          * Still in active use privately.
2783          *
2784          * @param $fragment \type{\string} text
2785          */
2786         public function setFragment( $fragment ) {
2787                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2788         }
2789
2790         /**
2791          * Get a Title object associated with the talk page of this article
2792          *
2793          * @return Title the object for the talk page
2794          */
2795         public function getTalkPage() {
2796                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2797         }
2798
2799         /**
2800          * Get a title object associated with the subject page of this
2801          * talk page
2802          *
2803          * @return Title the object for the subject page
2804          */
2805         public function getSubjectPage() {
2806                 // Is this the same title?
2807                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2808                 if ( $this->getNamespace() == $subjectNS ) {
2809                         return $this;
2810                 }
2811                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2812         }
2813
2814         /**
2815          * Get an array of Title objects linking to this Title
2816          * Also stores the IDs in the link cache.
2817          *
2818          * WARNING: do not use this function on arbitrary user-supplied titles!
2819          * On heavily-used templates it will max out the memory.
2820          *
2821          * @param $options Array: may be FOR UPDATE
2822          * @param $table String: table name
2823          * @param $prefix String: fields prefix
2824          * @return \type{\arrayof{Title}} the Title objects linking here
2825          */
2826         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2827                 $linkCache = LinkCache::singleton();
2828
2829                 if ( count( $options ) > 0 ) {
2830                         $db = wfGetDB( DB_MASTER );
2831                 } else {
2832                         $db = wfGetDB( DB_SLAVE );
2833                 }
2834
2835                 $res = $db->select(
2836                         array( 'page', $table ),
2837                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2838                         array(
2839                                 "{$prefix}_from=page_id",
2840                                 "{$prefix}_namespace" => $this->getNamespace(),
2841                                 "{$prefix}_title"     => $this->getDBkey() ),
2842                         __METHOD__,
2843                         $options
2844                 );
2845
2846                 $retVal = array();
2847                 if ( $db->numRows( $res ) ) {
2848                         foreach ( $res as $row ) {
2849                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2850                                 if ( $titleObj ) {
2851                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2852                                         $retVal[] = $titleObj;
2853                                 }
2854                         }
2855                 }
2856                 return $retVal;
2857         }
2858
2859         /**
2860          * Get an array of Title objects using this Title as a template
2861          * Also stores the IDs in the link cache.
2862          *
2863          * WARNING: do not use this function on arbitrary user-supplied titles!
2864          * On heavily-used templates it will max out the memory.
2865          *
2866          * @param $options Array: may be FOR UPDATE
2867          * @return \type{\arrayof{Title}} the Title objects linking here
2868          */
2869         public function getTemplateLinksTo( $options = array() ) {
2870                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2871         }
2872
2873         /**
2874          * Get an array of Title objects referring to non-existent articles linked from this page
2875          *
2876          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2877          * @return \type{\arrayof{Title}} the Title objects
2878          */
2879         public function getBrokenLinksFrom() {
2880                 if ( $this->getArticleId() == 0 ) {
2881                         # All links from article ID 0 are false positives
2882                         return array();
2883                 }
2884
2885                 $dbr = wfGetDB( DB_SLAVE );
2886                 $res = $dbr->select(
2887                         array( 'page', 'pagelinks' ),
2888                         array( 'pl_namespace', 'pl_title' ),
2889                         array(
2890                                 'pl_from' => $this->getArticleId(),
2891                                 'page_namespace IS NULL'
2892                         ),
2893                         __METHOD__, array(),
2894                         array(
2895                                 'page' => array(
2896                                         'LEFT JOIN',
2897                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2898                                 )
2899                         )
2900                 );
2901
2902                 $retVal = array();
2903                 foreach ( $res as $row ) {
2904                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2905                 }
2906                 return $retVal;
2907         }
2908
2909
2910         /**
2911          * Get a list of URLs to purge from the Squid cache when this
2912          * page changes
2913          *
2914          * @return \type{\arrayof{\string}} the URLs
2915          */
2916         public function getSquidURLs() {
2917                 global $wgContLang;
2918
2919                 $urls = array(
2920                         $this->getInternalURL(),
2921                         $this->getInternalURL( 'action=history' )
2922                 );
2923
2924                 // purge variant urls as well
2925                 if ( $wgContLang->hasVariants() ) {
2926                         $variants = $wgContLang->getVariants();
2927                         foreach ( $variants as $vCode ) {
2928                                 $urls[] = $this->getInternalURL( '', $vCode );
2929                         }
2930                 }
2931
2932                 return $urls;
2933         }
2934
2935         /**
2936          * Purge all applicable Squid URLs
2937          */
2938         public function purgeSquid() {
2939                 global $wgUseSquid;
2940                 if ( $wgUseSquid ) {
2941                         $urls = $this->getSquidURLs();
2942                         $u = new SquidUpdate( $urls );
2943                         $u->doUpdate();
2944                 }
2945         }
2946
2947         /**
2948          * Move this page without authentication
2949          *
2950          * @param $nt \type{Title} the new page Title
2951          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2952          */
2953         public function moveNoAuth( &$nt ) {
2954                 return $this->moveTo( $nt, false );
2955         }
2956
2957         /**
2958          * Check whether a given move operation would be valid.
2959          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2960          *
2961          * @param $nt \type{Title} the new title
2962          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2963          *  should be checked
2964          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2965          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2966          */
2967         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2968                 global $wgUser;
2969
2970                 $errors = array();
2971                 if ( !$nt ) {
2972                         // Normally we'd add this to $errors, but we'll get
2973                         // lots of syntax errors if $nt is not an object
2974                         return array( array( 'badtitletext' ) );
2975                 }
2976                 if ( $this->equals( $nt ) ) {
2977                         $errors[] = array( 'selfmove' );
2978                 }
2979                 if ( !$this->isMovable() ) {
2980                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2981                 }
2982                 if ( $nt->getInterwiki() != '' ) {
2983                         $errors[] = array( 'immobile-target-namespace-iw' );
2984                 }
2985                 if ( !$nt->isMovable() ) {
2986                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2987                 }
2988
2989                 $oldid = $this->getArticleID();
2990                 $newid = $nt->getArticleID();
2991
2992                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2993                         $errors[] = array( 'articleexists' );
2994                 }
2995                 if ( ( $this->getDBkey() == '' ) ||
2996                          ( !$oldid ) ||
2997                      ( $nt->getDBkey() == '' ) ) {
2998                         $errors[] = array( 'badarticleerror' );
2999                 }
3000
3001                 // Image-specific checks
3002                 if ( $this->getNamespace() == NS_FILE ) {
3003                         if ( $nt->getNamespace() != NS_FILE ) {
3004                                 $errors[] = array( 'imagenocrossnamespace' );
3005                         }
3006                         $file = wfLocalFile( $this );
3007                         if ( $file->exists() ) {
3008                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3009                                         $errors[] = array( 'imageinvalidfilename' );
3010                                 }
3011                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3012                                         $errors[] = array( 'imagetypemismatch' );
3013                                 }
3014                         }
3015                         $destfile = wfLocalFile( $nt );
3016                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3017                                 $errors[] = array( 'file-exists-sharedrepo' );
3018                         }
3019                 }
3020
3021                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3022                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3023                 }
3024
3025                 if ( $auth ) {
3026                         $errors = wfMergeErrorArrays( $errors,
3027                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3028                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3029                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3030                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3031                 }
3032
3033                 $match = EditPage::matchSummarySpamRegex( $reason );
3034                 if ( $match !== false ) {
3035                         // This is kind of lame, won't display nice
3036                         $errors[] = array( 'spamprotectiontext' );
3037                 }
3038
3039                 $err = null;
3040                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3041                         $errors[] = array( 'hookaborted', $err );
3042                 }
3043
3044                 # The move is allowed only if (1) the target doesn't exist, or
3045                 # (2) the target is a redirect to the source, and has no history
3046                 # (so we can undo bad moves right after they're done).
3047
3048                 if ( 0 != $newid ) { # Target exists; check for validity
3049                         if ( !$this->isValidMoveTarget( $nt ) ) {
3050                                 $errors[] = array( 'articleexists' );
3051                         }
3052                 } else {
3053                         $tp = $nt->getTitleProtection();
3054                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3055                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3056                                 $errors[] = array( 'cantmove-titleprotected' );
3057                         }
3058                 }
3059                 if ( empty( $errors ) ) {
3060                         return true;
3061                 }
3062                 return $errors;
3063         }
3064
3065         /**
3066          * Move a title to a new location
3067          *
3068          * @param $nt \type{Title} the new title
3069          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3070          *  should be checked
3071          * @param $reason \type{\string} The reason for the move
3072          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3073          *  Ignored if the user doesn't have the suppressredirect right.
3074          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3075          */
3076         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3077                 global $wgContLang;
3078
3079                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3080                 if ( is_array( $err ) ) {
3081                         return $err;
3082                 }
3083
3084                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3085                 $dbw = wfGetDB( DB_MASTER );
3086                 if ( $this->getNamespace() == NS_FILE ) {
3087                         $file = wfLocalFile( $this );
3088                         if ( $file->exists() ) {
3089                                 $status = $file->move( $nt );
3090                                 if ( !$status->isOk() ) {
3091                                         return $status->getErrorsArray();
3092                                 }
3093                         }
3094                 }
3095
3096                 $pageid = $this->getArticleID();
3097                 $protected = $this->isProtected();
3098                 if ( $nt->exists() ) {
3099                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3100                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3101                 } else { # Target didn't exist, do normal move.
3102                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3103                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3104                 }
3105
3106                 if ( is_array( $err ) ) {
3107                         return $err;
3108                 }
3109                 $redirid = $this->getArticleID();
3110
3111                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3112                 // cl_timestamp, which may disturb time-based lists on some sites.
3113                 $prefix = $dbw->selectField(
3114                         'categorylinks',
3115                         'cl_sortkey_prefix',
3116                         array( 'cl_from' => $pageid ),
3117                         __METHOD__
3118                 );
3119                 $dbw->update( 'categorylinks',
3120                         array(
3121                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3122                                 'cl_timestamp=cl_timestamp' ),
3123                         array( 'cl_from' => $pageid ),
3124                         __METHOD__ );
3125
3126                 if ( $protected ) {
3127                         # Protect the redirect title as the title used to be...
3128                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3129                                 array(
3130                                         'pr_page'    => $redirid,
3131                                         'pr_type'    => 'pr_type',
3132                                         'pr_level'   => 'pr_level',
3133                                         'pr_cascade' => 'pr_cascade',
3134                                         'pr_user'    => 'pr_user',
3135                                         'pr_expiry'  => 'pr_expiry'
3136                                 ),
3137                                 array( 'pr_page' => $pageid ),
3138                                 __METHOD__,
3139                                 array( 'IGNORE' )
3140                         );
3141                         # Update the protection log
3142                         $log = new LogPage( 'protect' );
3143                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3144                         if ( $reason ) {
3145                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3146                         }
3147                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3148                 }
3149
3150                 # Update watchlists
3151                 $oldnamespace = $this->getNamespace() & ~1;
3152                 $newnamespace = $nt->getNamespace() & ~1;
3153                 $oldtitle = $this->getDBkey();
3154                 $newtitle = $nt->getDBkey();
3155
3156                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3157                         WatchedItem::duplicateEntries( $this, $nt );
3158                 }
3159
3160                 # Update search engine
3161                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3162                 $u->doUpdate();
3163                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3164                 $u->doUpdate();
3165
3166                 # Update site_stats
3167                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3168                         # No longer a content page
3169                         # Not viewed, edited, removing
3170                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3171                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3172                         # Now a content page
3173                         # Not viewed, edited, adding
3174                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3175                 } elseif ( $pageCountChange ) {
3176                         # Redirect added
3177                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3178                 } else {
3179                         # Nothing special
3180                         $u = false;
3181                 }
3182                 if ( $u ) {
3183                         $u->doUpdate();
3184                 }
3185                 # Update message cache for interface messages
3186                 global $wgMessageCache;
3187                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3188                         # @bug 17860: old article can be deleted, if this the case,
3189                         # delete it from message cache
3190                         if ( $this->getArticleID() === 0 ) {
3191                                 $wgMessageCache->replace( $this->getDBkey(), false );
3192                         } else {
3193                                 $oldarticle = new Article( $this );
3194                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3195                         }
3196                 }
3197                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3198                         $newarticle = new Article( $nt );
3199                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3200                 }
3201
3202                 global $wgUser;
3203                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3204                 return true;
3205         }
3206
3207         /**
3208          * Move page to a title which is at present a redirect to the
3209          * source page
3210          *
3211          * @param $nt \type{Title} the page to move to, which should currently
3212          *  be a redirect
3213          * @param $reason \type{\string} The reason for the move
3214          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3215          *  Ignored if the user doesn't have the suppressredirect right
3216          */
3217         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3218                 global $wgUseSquid, $wgUser, $wgContLang;
3219
3220                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3221
3222                 if ( $reason ) {
3223                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3224                 }
3225                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3226                 $comment = $wgContLang->truncate( $comment, 250 );
3227
3228                 $now = wfTimestampNow();
3229                 $newid = $nt->getArticleID();
3230                 $oldid = $this->getArticleID();
3231                 $latest = $this->getLatestRevID();
3232
3233                 $dbw = wfGetDB( DB_MASTER );
3234
3235                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3236                 $newns = $nt->getNamespace();
3237                 $newdbk = $nt->getDBkey();
3238
3239                 # Delete the old redirect. We don't save it to history since
3240                 # by definition if we've got here it's rather uninteresting.
3241                 # We have to remove it so that the next step doesn't trigger
3242                 # a conflict on the unique namespace+title index...
3243                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3244                 if ( !$dbw->cascadingDeletes() ) {
3245                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3246                         global $wgUseTrackbacks;
3247                         if ( $wgUseTrackbacks ) {
3248                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3249                         }
3250                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3251                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3252                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3253                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3254                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3255                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3256                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3257                 }
3258                 // If the redirect was recently created, it may have an entry in recentchanges still
3259                 $dbw->delete( 'recentchanges',
3260                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3261                         __METHOD__
3262                 );
3263
3264                 # Save a null revision in the page's history notifying of the move
3265                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3266                 $nullRevId = $nullRevision->insertOn( $dbw );
3267
3268                 $article = new Article( $this );
3269                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3270
3271                 # Change the name of the target page:
3272                 $dbw->update( 'page',
3273                         /* SET */ array(
3274                                 'page_touched'   => $dbw->timestamp( $now ),
3275                                 'page_namespace' => $nt->getNamespace(),
3276                                 'page_title'     => $nt->getDBkey(),
3277                                 'page_latest'    => $nullRevId,
3278                         ),
3279                         /* WHERE */ array( 'page_id' => $oldid ),
3280                         __METHOD__
3281                 );
3282                 $nt->resetArticleID( $oldid );
3283
3284                 # Recreate the redirect, this time in the other direction.
3285                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3286                         $mwRedir = MagicWord::get( 'redirect' );
3287                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3288                         $redirectArticle = new Article( $this );
3289                         $newid = $redirectArticle->insertOn( $dbw );
3290                         $redirectRevision = new Revision( array(
3291                                 'page'    => $newid,
3292                                 'comment' => $comment,
3293                                 'text'    => $redirectText ) );
3294                         $redirectRevision->insertOn( $dbw );
3295                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3296
3297                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3298
3299                         # Now, we record the link from the redirect to the new title.
3300                         # It should have no other outgoing links...
3301                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3302                         $dbw->insert( 'pagelinks',
3303                                 array(
3304                                         'pl_from'      => $newid,
3305                                         'pl_namespace' => $nt->getNamespace(),
3306                                         'pl_title'     => $nt->getDBkey() ),
3307                                 __METHOD__ );
3308                         $redirectSuppressed = false;
3309                 } else {
3310                         $this->resetArticleID( 0 );
3311                         $redirectSuppressed = true;
3312                 }
3313
3314                 # Log the move
3315                 $log = new LogPage( 'move' );
3316                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3317
3318                 # Purge squid
3319                 if ( $wgUseSquid ) {
3320                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3321                         $u = new SquidUpdate( $urls );
3322                         $u->doUpdate();
3323                 }
3324
3325         }
3326
3327         /**
3328          * Move page to non-existing title.
3329          *
3330          * @param $nt \type{Title} the new Title
3331          * @param $reason \type{\string} The reason for the move
3332          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3333          *  Ignored if the user doesn't have the suppressredirect right
3334          */
3335         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3336                 global $wgUser, $wgContLang;
3337
3338                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3339                 if ( $reason ) {
3340                         $comment .= wfMsgExt( 'colon-separator',
3341                                 array( 'escapenoentities', 'content' ) );
3342                         $comment .= $reason;
3343                 }
3344                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3345                 $comment = $wgContLang->truncate( $comment, 250 );
3346
3347                 $oldid = $this->getArticleID();
3348                 $latest = $this->getLatestRevId();
3349
3350                 $dbw = wfGetDB( DB_MASTER );
3351                 $now = $dbw->timestamp();
3352
3353                 # Save a null revision in the page's history notifying of the move
3354                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3355                 if ( !is_object( $nullRevision ) ) {
3356                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3357                 }
3358                 $nullRevId = $nullRevision->insertOn( $dbw );
3359
3360                 $article = new Article( $this );
3361                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3362
3363                 # Rename page entry
3364                 $dbw->update( 'page',
3365                         /* SET */ array(
3366                                 'page_touched'   => $now,
3367                                 'page_namespace' => $nt->getNamespace(),
3368                                 'page_title'     => $nt->getDBkey(),
3369                                 'page_latest'    => $nullRevId,
3370                         ),
3371                         /* WHERE */ array( 'page_id' => $oldid ),
3372                         __METHOD__
3373                 );
3374                 $nt->resetArticleID( $oldid );
3375
3376                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3377                         # Insert redirect
3378                         $mwRedir = MagicWord::get( 'redirect' );
3379                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3380                         $redirectArticle = new Article( $this );
3381                         $newid = $redirectArticle->insertOn( $dbw );
3382                         $redirectRevision = new Revision( array(
3383                                 'page'    => $newid,
3384                                 'comment' => $comment,
3385                                 'text'    => $redirectText ) );
3386                         $redirectRevision->insertOn( $dbw );
3387                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3388
3389                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3390
3391                         # Record the just-created redirect's linking to the page
3392                         $dbw->insert( 'pagelinks',
3393                                 array(
3394                                         'pl_from'      => $newid,
3395                                         'pl_namespace' => $nt->getNamespace(),
3396                                         'pl_title'     => $nt->getDBkey() ),
3397                                 __METHOD__ );
3398                         $redirectSuppressed = false;
3399                 } else {
3400                         $this->resetArticleID( 0 );
3401                         $redirectSuppressed = true;
3402                 }
3403
3404                 # Log the move
3405                 $log = new LogPage( 'move' );
3406                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3407
3408                 # Purge caches as per article creation
3409                 Article::onArticleCreate( $nt );
3410
3411                 # Purge old title from squid
3412                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3413                 $this->purgeSquid();
3414         }
3415
3416         /**
3417          * Move this page's subpages to be subpages of $nt
3418          *
3419          * @param $nt Title Move target
3420          * @param $auth bool Whether $wgUser's permissions should be checked
3421          * @param $reason string The reason for the move
3422          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3423          *  Ignored if the user doesn't have the 'suppressredirect' right
3424          * @return mixed array with old page titles as keys, and strings (new page titles) or
3425          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3426          */
3427         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3428                 global $wgMaximumMovedPages;
3429                 // Check permissions
3430                 if ( !$this->userCan( 'move-subpages' ) ) {
3431                         return array( 'cant-move-subpages' );
3432                 }
3433                 // Do the source and target namespaces support subpages?
3434                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3435                         return array( 'namespace-nosubpages',
3436                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3437                 }
3438                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3439                         return array( 'namespace-nosubpages',
3440                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3441                 }
3442
3443                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3444                 $retval = array();
3445                 $count = 0;
3446                 foreach ( $subpages as $oldSubpage ) {
3447                         $count++;
3448                         if ( $count > $wgMaximumMovedPages ) {
3449                                 $retval[$oldSubpage->getPrefixedTitle()] =
3450                                                 array( 'movepage-max-pages',
3451                                                         $wgMaximumMovedPages );
3452                                 break;
3453                         }
3454
3455                         // We don't know whether this function was called before
3456                         // or after moving the root page, so check both
3457                         // $this and $nt
3458                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3459                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3460                         {
3461                                 // When moving a page to a subpage of itself,
3462                                 // don't move it twice
3463                                 continue;
3464                         }
3465                         $newPageName = preg_replace(
3466                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3467                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3468                                         $oldSubpage->getDBkey() );
3469                         if ( $oldSubpage->isTalkPage() ) {
3470                                 $newNs = $nt->getTalkPage()->getNamespace();
3471                         } else {
3472                                 $newNs = $nt->getSubjectPage()->getNamespace();
3473                         }
3474                         # Bug 14385: we need makeTitleSafe because the new page names may
3475                         # be longer than 255 characters.
3476                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3477
3478                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3479                         if ( $success === true ) {
3480                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3481                         } else {
3482                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3483                         }
3484                 }
3485                 return $retval;
3486         }
3487
3488         /**
3489          * Checks if this page is just a one-rev redirect.
3490          * Adds lock, so don't use just for light purposes.
3491          *
3492          * @return \type{\bool}
3493          */
3494         public function isSingleRevRedirect() {
3495                 $dbw = wfGetDB( DB_MASTER );
3496                 # Is it a redirect?
3497                 $row = $dbw->selectRow( 'page',
3498                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3499                         $this->pageCond(),
3500                         __METHOD__,
3501                         array( 'FOR UPDATE' )
3502                 );
3503                 # Cache some fields we may want
3504                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3505                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3506                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3507                 if ( !$this->mRedirect ) {
3508                         return false;
3509                 }
3510                 # Does the article have a history?
3511                 $row = $dbw->selectField( array( 'page', 'revision' ),
3512                         'rev_id',
3513                         array( 'page_namespace' => $this->getNamespace(),
3514                                 'page_title' => $this->getDBkey(),
3515                                 'page_id=rev_page',
3516                                 'page_latest != rev_id'
3517                         ),
3518                         __METHOD__,
3519                         array( 'FOR UPDATE' )
3520                 );
3521                 # Return true if there was no history
3522                 return ( $row === false );
3523         }
3524
3525         /**
3526          * Checks if $this can be moved to a given Title
3527          * - Selects for update, so don't call it unless you mean business
3528          *
3529          * @param $nt \type{Title} the new title to check
3530          * @return \type{\bool} TRUE or FALSE
3531          */
3532         public function isValidMoveTarget( $nt ) {
3533                 # Is it an existing file?
3534                 if ( $nt->getNamespace() == NS_FILE ) {
3535                         $file = wfLocalFile( $nt );
3536                         if ( $file->exists() ) {
3537                                 wfDebug( __METHOD__ . ": file exists\n" );
3538                                 return false;
3539                         }
3540                 }
3541                 # Is it a redirect with no history?
3542                 if ( !$nt->isSingleRevRedirect() ) {
3543                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3544                         return false;
3545                 }
3546                 # Get the article text
3547                 $rev = Revision::newFromTitle( $nt );
3548                 $text = $rev->getText();
3549                 # Does the redirect point to the source?
3550                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3551                 $m = array();
3552                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3553                         $redirTitle = Title::newFromText( $m[1] );
3554                         if ( !is_object( $redirTitle ) ||
3555                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3556                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3557                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3558                                 return false;
3559                         }
3560                 } else {
3561                         # Fail safe
3562                         wfDebug( __METHOD__ . ": failsafe\n" );
3563                         return false;
3564                 }
3565                 return true;
3566         }
3567
3568         /**
3569          * Can this title be added to a user's watchlist?
3570          *
3571          * @return \type{\bool} TRUE or FALSE
3572          */
3573         public function isWatchable() {
3574                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3575         }
3576
3577         /**
3578          * Get categories to which this Title belongs and return an array of
3579          * categories' names.
3580          *
3581          * @return \type{\array} array an array of parents in the form:
3582          *      $parent => $currentarticle
3583          */
3584         public function getParentCategories() {
3585                 global $wgContLang;
3586
3587                 $titlekey = $this->getArticleId();
3588                 $dbr = wfGetDB( DB_SLAVE );
3589                 $categorylinks = $dbr->tableName( 'categorylinks' );
3590
3591                 # NEW SQL
3592                 $sql = "SELECT * FROM $categorylinks"
3593                      . " WHERE cl_from='$titlekey'"
3594                          . " AND cl_from <> '0'"
3595                          . " ORDER BY cl_sortkey";
3596
3597                 $res = $dbr->query( $sql );
3598                 $data = array();
3599
3600                 if ( $dbr->numRows( $res ) > 0 ) {
3601                         foreach ( $res as $row ) {
3602                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3603                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3604                         }
3605                 }
3606                 return $data;
3607         }
3608
3609         /**
3610          * Get a tree of parent categories
3611          *
3612          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3613          * @return \type{\array} Tree of parent categories
3614          */
3615         public function getParentCategoryTree( $children = array() ) {
3616                 $stack = array();
3617                 $parents = $this->getParentCategories();
3618
3619                 if ( $parents ) {
3620                         foreach ( $parents as $parent => $current ) {
3621                                 if ( array_key_exists( $parent, $children ) ) {
3622                                         # Circular reference
3623                                         $stack[$parent] = array();
3624                                 } else {
3625                                         $nt = Title::newFromText( $parent );
3626                                         if ( $nt ) {
3627                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3628                                         }
3629                                 }
3630                         }
3631                 }
3632
3633                 return $stack;
3634         }
3635
3636
3637         /**
3638          * Get an associative array for selecting this title from
3639          * the "page" table
3640          *
3641          * @return \type{\array} Selection array
3642          */
3643         public function pageCond() {
3644                 if ( $this->mArticleID > 0 ) {
3645                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3646                         return array( 'page_id' => $this->mArticleID );
3647                 } else {
3648                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3649                 }
3650         }
3651
3652         /**
3653          * Get the revision ID of the previous revision
3654          *
3655          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3656          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3657          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3658          */
3659         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3660                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3661                 return $db->selectField( 'revision', 'rev_id',
3662                         array(
3663                                 'rev_page' => $this->getArticleId( $flags ),
3664                                 'rev_id < ' . intval( $revId )
3665                         ),
3666                         __METHOD__,
3667                         array( 'ORDER BY' => 'rev_id DESC' )
3668                 );
3669         }
3670
3671         /**
3672          * Get the revision ID of the next revision
3673          *
3674          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3675          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3676          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3677          */
3678         public function getNextRevisionID( $revId, $flags = 0 ) {
3679                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3680                 return $db->selectField( 'revision', 'rev_id',
3681                         array(
3682                                 'rev_page' => $this->getArticleId( $flags ),
3683                                 'rev_id > ' . intval( $revId )
3684                         ),
3685                         __METHOD__,
3686                         array( 'ORDER BY' => 'rev_id' )
3687                 );
3688         }
3689
3690         /**
3691          * Get the first revision of the page
3692          *
3693          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3694          * @return Revision (or NULL if page doesn't exist)
3695          */
3696         public function getFirstRevision( $flags = 0 ) {
3697                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3698                 $pageId = $this->getArticleId( $flags );
3699                 if ( !$pageId ) {
3700                         return null;
3701                 }
3702                 $row = $db->selectRow( 'revision', '*',
3703                         array( 'rev_page' => $pageId ),
3704                         __METHOD__,
3705                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3706                 );
3707                 if ( !$row ) {
3708                         return null;
3709                 } else {
3710                         return new Revision( $row );
3711                 }
3712         }
3713
3714         /**
3715          * Check if this is a new page
3716          *
3717          * @return bool
3718          */
3719         public function isNewPage() {
3720                 $dbr = wfGetDB( DB_SLAVE );
3721                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3722         }
3723
3724         /**
3725          * Get the oldest revision timestamp of this page
3726          *
3727          * @return String: MW timestamp
3728          */
3729         public function getEarliestRevTime() {
3730                 $dbr = wfGetDB( DB_SLAVE );
3731                 if ( $this->exists() ) {
3732                         $min = $dbr->selectField( 'revision',
3733                                 'MIN(rev_timestamp)',
3734                                 array( 'rev_page' => $this->getArticleId() ),
3735                                 __METHOD__ );
3736                         return wfTimestampOrNull( TS_MW, $min );
3737                 }
3738                 return null;
3739         }
3740
3741         /**
3742          * Get the number of revisions between the given revision IDs.
3743          * Used for diffs and other things that really need it.
3744          *
3745          * @param $old \type{\int} Revision ID.
3746          * @param $new \type{\int} Revision ID.
3747          * @return \type{\int} Number of revisions between these IDs.
3748          */
3749         public function countRevisionsBetween( $old, $new ) {
3750                 $dbr = wfGetDB( DB_SLAVE );
3751                 return (int)$dbr->selectField( 'revision', 'count(*)',
3752                         'rev_page = ' . intval( $this->getArticleId() ) .
3753                         ' AND rev_id > ' . intval( $old ) .
3754                         ' AND rev_id < ' . intval( $new ),
3755                         __METHOD__
3756                 );
3757         }
3758
3759         /**
3760          * Get the number of authors between the given revision IDs.
3761          * Used for diffs and other things that really need it.
3762          *
3763          * @param $fromRevId \type{\int} Revision ID (first before range)
3764          * @param $toRevId \type{\int} Revision ID (first after range)
3765          * @param $limit \type{\int} Maximum number of authors
3766          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3767          * @return \type{\int}
3768          */
3769         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3770                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3771                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3772                         array(
3773                                 'rev_page = ' . $this->getArticleID(),
3774                                 'rev_id > ' . (int)$fromRevId,
3775                                 'rev_id < ' . (int)$toRevId
3776                         ), __METHOD__,
3777                         array( 'LIMIT' => $limit )
3778                 );
3779                 return (int)$db->numRows( $res );
3780         }
3781
3782         /**
3783          * Compare with another title.
3784          *
3785          * @param $title \type{Title}
3786          * @return \type{\bool} TRUE or FALSE
3787          */
3788         public function equals( Title $title ) {
3789                 // Note: === is necessary for proper matching of number-like titles.
3790                 return $this->getInterwiki() === $title->getInterwiki()
3791                         && $this->getNamespace() == $title->getNamespace()
3792                         && $this->getDBkey() === $title->getDBkey();
3793         }
3794
3795         /**
3796          * Callback for usort() to do title sorts by (namespace, title)
3797          *
3798          * @return Integer: result of string comparison, or namespace comparison
3799          */
3800         public static function compare( $a, $b ) {
3801                 if ( $a->getNamespace() == $b->getNamespace() ) {
3802                         return strcmp( $a->getText(), $b->getText() );
3803                 } else {
3804                         return $a->getNamespace() - $b->getNamespace();
3805                 }
3806         }
3807
3808         /**
3809          * Return a string representation of this title
3810          *
3811          * @return \type{\string} String representation of this title
3812          */
3813         public function __toString() {
3814                 return $this->getPrefixedText();
3815         }
3816
3817         /**
3818          * Check if page exists.  For historical reasons, this function simply
3819          * checks for the existence of the title in the page table, and will
3820          * thus return false for interwiki links, special pages and the like.
3821          * If you want to know if a title can be meaningfully viewed, you should
3822          * probably call the isKnown() method instead.
3823          *
3824          * @return \type{\bool}
3825          */
3826         public function exists() {
3827                 return $this->getArticleId() != 0;
3828         }
3829
3830         /**
3831          * Should links to this title be shown as potentially viewable (i.e. as
3832          * "bluelinks"), even if there's no record by this title in the page
3833          * table?
3834          *
3835          * This function is semi-deprecated for public use, as well as somewhat
3836          * misleadingly named.  You probably just want to call isKnown(), which
3837          * calls this function internally.
3838          *
3839          * (ISSUE: Most of these checks are cheap, but the file existence check
3840          * can potentially be quite expensive.  Including it here fixes a lot of
3841          * existing code, but we might want to add an optional parameter to skip
3842          * it and any other expensive checks.)
3843          *
3844          * @return \type{\bool}
3845          */
3846         public function isAlwaysKnown() {
3847                 if ( $this->mInterwiki != '' ) {
3848                         return true;  // any interwiki link might be viewable, for all we know
3849                 }
3850                 switch( $this->mNamespace ) {
3851                         case NS_MEDIA:
3852                         case NS_FILE:
3853                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3854                         case NS_SPECIAL:
3855                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3856                         case NS_MAIN:
3857                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3858                         case NS_MEDIAWIKI:
3859                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3860                                 // the full l10n of that language to be loaded. That takes much memory and
3861                                 // isn't needed. So we strip the language part away.
3862                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3863                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3864                         default:
3865                                 return false;
3866                 }
3867         }
3868
3869         /**
3870          * Does this title refer to a page that can (or might) be meaningfully
3871          * viewed?  In particular, this function may be used to determine if
3872          * links to the title should be rendered as "bluelinks" (as opposed to
3873          * "redlinks" to non-existent pages).
3874          *
3875          * @return \type{\bool}
3876          */
3877         public function isKnown() {
3878                 return $this->isAlwaysKnown() || $this->exists();
3879         }
3880
3881         /**
3882          * Does this page have source text?
3883          *
3884          * @return Boolean
3885          */
3886         public function hasSourceText() {
3887                 if ( $this->exists() ) {
3888                         return true;
3889                 }
3890
3891                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3892                         // If the page doesn't exist but is a known system message, default
3893                         // message content will be displayed, same for language subpages
3894                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3895                         // causes the full l10n of that language to be loaded. That takes much
3896                         // memory and isn't needed. So we strip the language part away.
3897                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3898                         return (bool)wfMsgWeirdKey( $basename );
3899                 }
3900
3901                 return false;
3902         }
3903
3904         /**
3905          * Is this in a namespace that allows actual pages?
3906          *
3907          * @return \type{\bool}
3908          * @internal note -- uses hardcoded namespace index instead of constants
3909          */
3910         public function canExist() {
3911                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3912         }
3913
3914         /**
3915          * Update page_touched timestamps and send squid purge messages for
3916          * pages linking to this title. May be sent to the job queue depending
3917          * on the number of links. Typically called on create and delete.
3918          */
3919         public function touchLinks() {
3920                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3921                 $u->doUpdate();
3922
3923                 if ( $this->getNamespace() == NS_CATEGORY ) {
3924                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3925                         $u->doUpdate();
3926                 }
3927         }
3928
3929         /**
3930          * Get the last touched timestamp
3931          *
3932          * @param $db DatabaseBase: optional db
3933          * @return \type{\string} Last touched timestamp
3934          */
3935         public function getTouched( $db = null ) {
3936                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3937                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3938                 return $touched;
3939         }
3940
3941         /**
3942          * Get the timestamp when this page was updated since the user last saw it.
3943          *
3944          * @param $user User
3945          * @return Mixed: string/null
3946          */
3947         public function getNotificationTimestamp( $user = null ) {
3948                 global $wgUser, $wgShowUpdatedMarker;
3949                 // Assume current user if none given
3950                 if ( !$user ) {
3951                         $user = $wgUser;
3952                 }
3953                 // Check cache first
3954                 $uid = $user->getId();
3955                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3956                         return $this->mNotificationTimestamp[$uid];
3957                 }
3958                 if ( !$uid || !$wgShowUpdatedMarker ) {
3959                         return $this->mNotificationTimestamp[$uid] = false;
3960                 }
3961                 // Don't cache too much!
3962                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3963                         $this->mNotificationTimestamp = array();
3964                 }
3965                 $dbr = wfGetDB( DB_SLAVE );
3966                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3967                         'wl_notificationtimestamp',
3968                         array( 'wl_namespace' => $this->getNamespace(),
3969                                 'wl_title' => $this->getDBkey(),
3970                                 'wl_user' => $user->getId()
3971                         ),
3972                         __METHOD__
3973                 );
3974                 return $this->mNotificationTimestamp[$uid];
3975         }
3976
3977         /**
3978          * Get the trackback URL for this page
3979          *
3980          * @return \type{\string} Trackback URL
3981          */
3982         public function trackbackURL() {
3983                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3984
3985                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3986                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3987         }
3988
3989         /**
3990          * Get the trackback RDF for this page
3991          *
3992          * @return \type{\string} Trackback RDF
3993          */
3994         public function trackbackRDF() {
3995                 $url = htmlspecialchars( $this->getFullURL() );
3996                 $title = htmlspecialchars( $this->getText() );
3997                 $tburl = $this->trackbackURL();
3998
3999                 // Autodiscovery RDF is placed in comments so HTML validator
4000                 // won't barf. This is a rather icky workaround, but seems
4001                 // frequently used by this kind of RDF thingy.
4002                 //
4003                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4004                 return "<!--
4005 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4006          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4007          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4008 <rdf:Description
4009    rdf:about=\"$url\"
4010    dc:identifier=\"$url\"
4011    dc:title=\"$title\"
4012    trackback:ping=\"$tburl\" />
4013 </rdf:RDF>
4014 -->";
4015         }
4016
4017         /**
4018          * Generate strings used for xml 'id' names in monobook tabs
4019          *
4020          * @param $prepend string defaults to 'nstab-'
4021          * @return \type{\string} XML 'id' name
4022          */
4023         public function getNamespaceKey( $prepend = 'nstab-' ) {
4024                 global $wgContLang;
4025                 // Gets the subject namespace if this title
4026                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4027                 // Checks if cononical namespace name exists for namespace
4028                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4029                         // Uses canonical namespace name
4030                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4031                 } else {
4032                         // Uses text of namespace
4033                         $namespaceKey = $this->getSubjectNsText();
4034                 }
4035                 // Makes namespace key lowercase
4036                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4037                 // Uses main
4038                 if ( $namespaceKey == '' ) {
4039                         $namespaceKey = 'main';
4040                 }
4041                 // Changes file to image for backwards compatibility
4042                 if ( $namespaceKey == 'file' ) {
4043                         $namespaceKey = 'image';
4044                 }
4045                 return $prepend . $namespaceKey;
4046         }
4047
4048         /**
4049          * Returns true if this is a special page.
4050          *
4051          * @return boolean
4052          */
4053         public function isSpecialPage() {
4054                 return $this->getNamespace() == NS_SPECIAL;
4055         }
4056
4057         /**
4058          * Returns true if this title resolves to the named special page
4059          *
4060          * @param $name \type{\string} The special page name
4061          * @return boolean
4062          */
4063         public function isSpecial( $name ) {
4064                 if ( $this->getNamespace() == NS_SPECIAL ) {
4065                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4066                         if ( $name == $thisName ) {
4067                                 return true;
4068                         }
4069                 }
4070                 return false;
4071         }
4072
4073         /**
4074          * If the Title refers to a special page alias which is not the local default,
4075          *
4076          * @return \type{Title} A new Title which points to the local default.
4077          *         Otherwise, returns $this.
4078          */
4079         public function fixSpecialName() {
4080                 if ( $this->getNamespace() == NS_SPECIAL ) {
4081                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4082                         if ( $canonicalName ) {
4083                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4084                                 if ( $localName != $this->mDbkeyform ) {
4085                                         return Title::makeTitle( NS_SPECIAL, $localName );
4086                                 }
4087                         }
4088                 }
4089                 return $this;
4090         }
4091
4092         /**
4093          * Is this Title in a namespace which contains content?
4094          * In other words, is this a content page, for the purposes of calculating
4095          * statistics, etc?
4096          *
4097          * @return Boolean
4098          */
4099         public function isContentPage() {
4100                 return MWNamespace::isContent( $this->getNamespace() );
4101         }
4102
4103         /**
4104          * Get all extant redirects to this Title
4105          *
4106          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4107          *            NULL to consider all namespaces
4108          * @return \type{\arrayof{Title}} Redirects to this title
4109          */
4110         public function getRedirectsHere( $ns = null ) {
4111                 $redirs = array();
4112
4113                 $dbr = wfGetDB( DB_SLAVE );
4114                 $where = array(
4115                         'rd_namespace' => $this->getNamespace(),
4116                         'rd_title' => $this->getDBkey(),
4117                         'rd_from = page_id'
4118                 );
4119                 if ( !is_null( $ns ) ) {
4120                         $where['page_namespace'] = $ns;
4121                 }
4122
4123                 $res = $dbr->select(
4124                         array( 'redirect', 'page' ),
4125                         array( 'page_namespace', 'page_title' ),
4126                         $where,
4127                         __METHOD__
4128                 );
4129
4130                 foreach ( $res as $row ) {
4131                         $redirs[] = self::newFromRow( $row );
4132                 }
4133                 return $redirs;
4134         }
4135
4136         /**
4137          * Check if this Title is a valid redirect target
4138          *
4139          * @return \type{\bool}
4140          */
4141         public function isValidRedirectTarget() {
4142                 global $wgInvalidRedirectTargets;
4143
4144                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4145                 if ( $this->isSpecial( 'Userlogout' ) ) {
4146                         return false;
4147                 }
4148
4149                 foreach ( $wgInvalidRedirectTargets as $target ) {
4150                         if ( $this->isSpecial( $target ) ) {
4151                                 return false;
4152                         }
4153                 }
4154
4155                 return true;
4156         }
4157
4158         /**
4159          * Get a backlink cache object
4160          *
4161          * @return object BacklinkCache
4162          */
4163         function getBacklinkCache() {
4164                 if ( is_null( $this->mBacklinkCache ) ) {
4165                         $this->mBacklinkCache = new BacklinkCache( $this );
4166                 }
4167                 return $this->mBacklinkCache;
4168         }
4169
4170         /**
4171          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4172          * this page.
4173          *
4174          * @return Boolean
4175          */
4176         public function canUseNoindex() {
4177                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4178
4179                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4180                         ? $wgContentNamespaces
4181                         : $wgExemptFromUserRobotsControl;
4182
4183                 return !in_array( $this->mNamespace, $bannedNamespaces );
4184
4185         }
4186
4187         /**
4188          * Returns restriction types for the current Title
4189          *
4190          * @return array applicable restriction types
4191          */
4192         public function getRestrictionTypes() {
4193                 global $wgRestrictionTypes;
4194                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4195
4196                 if ( $this->getNamespace() == NS_FILE ) {
4197                         $types[] = 'upload';
4198                 }
4199
4200                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4201
4202                 return $types;
4203         }
4204
4205         /**
4206          * Returns the raw sort key to be used for categories, with the specified
4207          * prefix.  This will be fed to Language::convertToSortkey() to get a
4208          * binary sortkey that can be used for actual sorting.
4209          *
4210          * @param $prefix string The prefix to be used, specified using
4211          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4212          *   prefix.
4213          * @return string
4214          */
4215         public function getCategorySortkey( $prefix = '' ) {
4216                 $unprefixed = $this->getText();
4217                 if ( $prefix !== '' ) {
4218                         # Separate with a null byte, so the unprefixed part is only used as
4219                         # a tiebreaker when two pages have the exact same prefix -- null
4220                         # sorts before everything else (hopefully).
4221                         return "$prefix\0$unprefixed";
4222                 }
4223                 return $unprefixed;
4224         }
4225 }