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 \type{\string} Text with possible redirect
 333          * @return \type{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 \type{\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 \type{\int} Namespace index
 606          */
 607         public function getNamespace() { return $this->mNamespace; }
 608
 609         /**
 610          * Get the namespace text
 611          *
 612          * @return \type{\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, $wgUser;
 867
 868                 if ( is_array( $query ) ) {
 869                         $query = wfArrayToCGI( $query );
 870                 }
 871
 872                 // internal links should point to same variant as current page (only anonymous users)
 873                 if ( !$variant && $wgContLang->hasVariants() && !$wgUser->isLoggedIn() ) {
 874                         $pref = $wgContLang->getPreferredVariant( false );
 875                         if ( $pref != $wgContLang->getCode() ) {
 876                                 $variant = $pref;
 877                         }
 878                 }
 879
 880                 if ( $this->isExternal() ) {
 881                         $url = $this->getFullURL();
 882                         if ( $query ) {
 883                                 // This is currently only used for edit section links in the
 884                                 // context of interwiki transclusion. In theory we should
 885                                 // append the query to the end of any existing query string,
 886                                 // but interwiki transclusion is already broken in that case.
 887                                 $url .= "?$query";
 888                         }
 889                 } else {
 890                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 891                         if ( $query == '' ) {
 892                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 893                                         if ( !$wgVariantArticlePath ) {
 894                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 895                                         } else {
 896                                                 $variantArticlePath = $wgVariantArticlePath;
 897                                         }
 898                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 899                                         $url = str_replace( '$1', $dbkey, $url  );
 900                                 } else {
 901                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 902                                 }
 903                         } else {
 904                                 global $wgActionPaths;
 905                                 $url = false;
 906                                 $matches = array();
 907                                 if ( !empty( $wgActionPaths ) &&
 908                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 909                                 {
 910                                         $action = urldecode( $matches[2] );
 911                                         if ( isset( $wgActionPaths[$action] ) ) {
 912                                                 $query = $matches[1];
 913                                                 if ( isset( $matches[4] ) ) {
 914                                                         $query .= $matches[4];
 915                                                 }
 916                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 917                                                 if ( $query != '' ) {
 918                                                         $url = wfAppendQuery( $url, $query );
 919                                                 }
 920                                         }
 921                                 }
 922                                 if ( $url === false ) {
 923                                         if ( $query == '-' ) {
 924                                                 $query = '';
 925                                         }
 926                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 927                                 }
 928                         }
 929
 930                         // FIXME: this causes breakage in various places when we
 931                         // actually expected a local URL and end up with dupe prefixes.
 932                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 933                                 $url = $wgServer . $url;
 934                         }
 935                 }
 936                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 937                 return $url;
 938         }
 939
 940         /**
 941          * Get a URL that's the simplest URL that will be valid to link, locally,
 942          * to the current Title.  It includes the fragment, but does not include
 943          * the server unless action=render is used (or the link is external).  If
 944          * there's a fragment but the prefixed text is empty, we just return a link
 945          * to the fragment.
 946          *
 947          * The result obviously should not be URL-escaped, but does need to be
 948          * HTML-escaped if it's being output in HTML.
 949          *
 950          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 951          *   query string.  Keys and values will be escaped.
 952          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 953          *   for external links.  Default is "false" (same variant as current page,
 954          *   for anonymous users).
 955          * @return \type{\string} the URL
 956          */
 957         public function getLinkUrl( $query = array(), $variant = false ) {
 958                 wfProfileIn( __METHOD__ );
 959                 if ( $this->isExternal() ) {
 960                         $ret = $this->getFullURL( $query );
 961                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 962                         $ret = $this->getFragmentForURL();
 963                 } else {
 964                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 965                 }
 966                 wfProfileOut( __METHOD__ );
 967                 return $ret;
 968         }
 969
 970         /**
 971          * Get an HTML-escaped version of the URL form, suitable for
 972          * using in a link, without a server name or fragment
 973          *
 974          * @param $query \type{\string} an optional query string
 975          * @return \type{\string} the URL
 976          */
 977         public function escapeLocalURL( $query = '' ) {
 978                 return htmlspecialchars( $this->getLocalURL( $query ) );
 979         }
 980
 981         /**
 982          * Get an HTML-escaped version of the URL form, suitable for
 983          * using in a link, including the server name and fragment
 984          *
 985          * @param $query \type{\string} an optional query string
 986          * @return \type{\string} the URL
 987          */
 988         public function escapeFullURL( $query = '' ) {
 989                 return htmlspecialchars( $this->getFullURL( $query ) );
 990         }
 991
 992         /**
 993          * Get the URL form for an internal link.
 994          * - Used in various Squid-related code, in case we have a different
 995          * internal hostname for the server from the exposed one.
 996          *
 997          * @param $query \type{\string} an optional query string
 998          * @param $variant \type{\string} language variant of url (for sr, zh..)
 999          * @return \type{\string} the URL
1000          */
1001         public function getInternalURL( $query = '', $variant = false ) {
1002                 global $wgInternalServer;
1003                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
1004                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1005                 return $url;
1006         }
1007
1008         /**
1009          * Get the edit URL for this Title
1010          *
1011          * @return \type{\string} the URL, or a null string if this is an
1012          *  interwiki link
1013          */
1014         public function getEditURL() {
1015                 if ( $this->mInterwiki != '' ) {
1016                         return '';
1017                 }
1018                 $s = $this->getLocalURL( 'action=edit' );
1019
1020                 return $s;
1021         }
1022
1023         /**
1024          * Get the HTML-escaped displayable text form.
1025          * Used for the title field in <a> tags.
1026          *
1027          * @return \type{\string} the text, including any prefixes
1028          */
1029         public function getEscapedText() {
1030                 return htmlspecialchars( $this->getPrefixedText() );
1031         }
1032
1033         /**
1034          * Is this Title interwiki?
1035          *
1036          * @return \type{\bool}
1037          */
1038         public function isExternal() {
1039                 return ( $this->mInterwiki != '' );
1040         }
1041
1042         /**
1043          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1044          *
1045          * @param $action \type{\string} Action to check (default: edit)
1046          * @return \type{\bool}
1047          */
1048         public function isSemiProtected( $action = 'edit' ) {
1049                 if ( $this->exists() ) {
1050                         $restrictions = $this->getRestrictions( $action );
1051                         if ( count( $restrictions ) > 0 ) {
1052                                 foreach ( $restrictions as $restriction ) {
1053                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1054                                                 return false;
1055                                         }
1056                                 }
1057                         } else {
1058                                 # Not protected
1059                                 return false;
1060                         }
1061                         return true;
1062                 } else {
1063                         # If it doesn't exist, it can't be protected
1064                         return false;
1065                 }
1066         }
1067
1068         /**
1069          * Does the title correspond to a protected article?
1070          *
1071          * @param $action \type{\string} the action the page is protected from,
1072          * by default checks all actions.
1073          * @return \type{\bool}
1074          */
1075         public function isProtected( $action = '' ) {
1076                 global $wgRestrictionLevels;
1077
1078                 $restrictionTypes = $this->getRestrictionTypes();
1079
1080                 # Special pages have inherent protection
1081                 if( $this->getNamespace() == NS_SPECIAL ) {
1082                         return true;
1083                 }
1084
1085                 # Check regular protection levels
1086                 foreach ( $restrictionTypes as $type ) {
1087                         if ( $action == $type || $action == '' ) {
1088                                 $r = $this->getRestrictions( $type );
1089                                 foreach ( $wgRestrictionLevels as $level ) {
1090                                         if ( in_array( $level, $r ) && $level != '' ) {
1091                                                 return true;
1092                                         }
1093                                 }
1094                         }
1095                 }
1096
1097                 return false;
1098         }
1099
1100         /**
1101          * Is this a conversion table for the LanguageConverter?
1102          *
1103          * @return \type{\bool}
1104          */
1105         public function isConversionTable() {
1106                 if(
1107                         $this->getNamespace() == NS_MEDIAWIKI &&
1108                         strpos( $this->getText(), 'Conversiontable' ) !== false
1109                 )
1110                 {
1111                         return true;
1112                 }
1113
1114                 return false;
1115         }
1116
1117         /**
1118          * Is $wgUser watching this page?
1119          *
1120          * @return \type{\bool}
1121          */
1122         public function userIsWatching() {
1123                 global $wgUser;
1124
1125                 if ( is_null( $this->mWatched ) ) {
1126                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1127                                 $this->mWatched = false;
1128                         } else {
1129                                 $this->mWatched = $wgUser->isWatched( $this );
1130                         }
1131                 }
1132                 return $this->mWatched;
1133         }
1134
1135         /**
1136          * Can $wgUser perform $action on this page?
1137          * This skips potentially expensive cascading permission checks
1138          * as well as avoids expensive error formatting
1139          *
1140          * Suitable for use for nonessential UI controls in common cases, but
1141          * _not_ for functional access control.
1142          *
1143          * May provide false positives, but should never provide a false negative.
1144          *
1145          * @param $action \type{\string} action that permission needs to be checked for
1146          * @return \type{\bool}
1147          */
1148         public function quickUserCan( $action ) {
1149                 return $this->userCan( $action, false );
1150         }
1151
1152         /**
1153          * Determines if $wgUser is unable to edit this page because it has been protected
1154          * by $wgNamespaceProtection.
1155          *
1156          * @return \type{\bool}
1157          */
1158         public function isNamespaceProtected() {
1159                 global $wgNamespaceProtection, $wgUser;
1160                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1161                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1162                                 if ( $right != '' && !$wgUser->isAllowed( $right ) ) {
1163                                         return true;
1164                                 }
1165                         }
1166                 }
1167                 return false;
1168         }
1169
1170         /**
1171          * Can $wgUser perform $action on this page?
1172          *
1173          * @param $action \type{\string} action that permission needs to be checked for
1174          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1175          * @return \type{\bool}
1176          */
1177         public function userCan( $action, $doExpensiveQueries = true ) {
1178                 global $wgUser;
1179                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1180         }
1181
1182         /**
1183          * Can $user perform $action on this page?
1184          *
1185          * FIXME: This *does not* check throttles (User::pingLimiter()).
1186          *
1187          * @param $action \type{\string}action that permission needs to be checked for
1188          * @param $user \type{User} user to check
1189          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1190          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1191          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1192          */
1193         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1194                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1195
1196                 // Remove the errors being ignored.
1197                 foreach ( $errors as $index => $error ) {
1198                         $error_key = is_array( $error ) ? $error[0] : $error;
1199
1200                         if ( in_array( $error_key, $ignoreErrors ) ) {
1201                                 unset( $errors[$index] );
1202                         }
1203                 }
1204
1205                 return $errors;
1206         }
1207
1208         /**
1209          * Permissions checks that fail most often, and which are easiest to test.
1210          *
1211          * @param $action String the action to check
1212          * @param $user User user to check
1213          * @param $errors Array list of current errors
1214          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1215          * @param $short Boolean short circuit on first error
1216          *
1217          * @return Array list of errors
1218          */
1219         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1220                 if ( $action == 'create' ) {
1221                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1222                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1223                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1224                         }
1225                 } elseif ( $action == 'move' ) {
1226                         if ( !$user->isAllowed( 'move-rootuserpages' )
1227                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1228                                 // Show user page-specific message only if the user can move other pages
1229                                 $errors[] = array( 'cant-move-user-page' );
1230                         }
1231
1232                         // Check if user is allowed to move files if it's a file
1233                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1234                                 $errors[] = array( 'movenotallowedfile' );
1235                         }
1236
1237                         if ( !$user->isAllowed( 'move' ) ) {
1238                                 // User can't move anything
1239                                 global $wgGroupPermissions;
1240                                 $userCanMove = false;
1241                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1242                                         $userCanMove = $wgGroupPermissions['user']['move'];
1243                                 }
1244                                 $autoconfirmedCanMove = false;
1245                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1246                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1247                                 }
1248                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1249                                         // custom message if logged-in users without any special rights can move
1250                                         $errors[] = array( 'movenologintext' );
1251                                 } else {
1252                                         $errors[] = array( 'movenotallowed' );
1253                                 }
1254                         }
1255                 } elseif ( $action == 'move-target' ) {
1256                         if ( !$user->isAllowed( 'move' ) ) {
1257                                 // User can't move anything
1258                                 $errors[] = array( 'movenotallowed' );
1259                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1260                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1261                                 // Show user page-specific message only if the user can move other pages
1262                                 $errors[] = array( 'cant-move-to-user-page' );
1263                         }
1264                 } elseif ( !$user->isAllowed( $action ) ) {
1265                         // We avoid expensive display logic for quickUserCan's and such
1266                         $groups = false;
1267                         if ( !$short ) {
1268                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1269                                         User::getGroupsWithPermission( $action ) );
1270                         }
1271
1272                         if ( $groups ) {
1273                                 global $wgLang;
1274                                 $return = array(
1275                                         'badaccess-groups',
1276                                         $wgLang->commaList( $groups ),
1277                                         count( $groups )
1278                                 );
1279                         } else {
1280                                 $return = array( 'badaccess-group0' );
1281                         }
1282                         $errors[] = $return;
1283                 }
1284
1285                 return $errors;
1286         }
1287
1288         /**
1289          * Add the resulting error code to the errors array
1290          *
1291          * @param $errors Array list of current errors
1292          * @param $result Mixed result of errors
1293          *
1294          * @return Array list of errors
1295          */
1296         private function resultToError( $errors, $result ) {
1297                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1298                         // A single array representing an error
1299                         $errors[] = $result;
1300                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1301                         // A nested array representing multiple errors
1302                         $errors = array_merge( $errors, $result );
1303                 } else if ( $result !== '' && is_string( $result ) ) {
1304                         // A string representing a message-id
1305                         $errors[] = array( $result );
1306                 } else if ( $result === false ) {
1307                         // a generic "We don't want them to do that"
1308                         $errors[] = array( 'badaccess-group0' );
1309                 }
1310                 return $errors;
1311         }
1312
1313         /**
1314          * Check various permission hooks
1315          * @see checkQuickPermissions for parameter information
1316          */
1317         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1318                 // Use getUserPermissionsErrors instead
1319                 $result = '';
1320                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1321                         return $result ? array() : array( array( 'badaccess-group0' ) );
1322                 }
1323                 // Check getUserPermissionsErrors hook
1324                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1325                         $errors = $this->resultToError( $errors, $result );
1326                 }
1327                 // Check getUserPermissionsErrorsExpensive hook
1328                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1329                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1330                         $errors = $this->resultToError( $errors, $result );
1331                 }
1332
1333                 return $errors;
1334         }
1335
1336         /**
1337          * Check permissions on special pages & namespaces
1338          * @see checkQuickPermissions for parameter information
1339          */
1340         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1341                 # Only 'createaccount' and 'execute' can be performed on
1342                 # special pages, which don't actually exist in the DB.
1343                 $specialOKActions = array( 'createaccount', 'execute' );
1344                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1345                         $errors[] = array( 'ns-specialprotected' );
1346                 }
1347
1348                 # Check $wgNamespaceProtection for restricted namespaces
1349                 if ( $this->isNamespaceProtected() ) {
1350                         $ns = $this->mNamespace == NS_MAIN ?
1351                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1352                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1353                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1354                 }
1355
1356                 return $errors;
1357         }
1358
1359         /**
1360          * Check CSS/JS sub-page permissions
1361          * @see checkQuickPermissions for parameter information
1362          */
1363         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1364                 # Protect css/js subpages of user pages
1365                 # XXX: this might be better using restrictions
1366                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1367                 #      and $this->userCanEditJsSubpage() from working
1368                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1369                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1370                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1371                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1372                                 $errors[] = array( 'customcssjsprotected' );
1373                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1374                                 $errors[] = array( 'customcssjsprotected' );
1375                         }
1376                 }
1377
1378                 return $errors;
1379         }
1380
1381         /**
1382          * Check against page_restrictions table requirements on this
1383          * page. The user must possess all required rights for this
1384          * action.
1385          * @see checkQuickPermissions for parameter information
1386          */
1387         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1388                 foreach ( $this->getRestrictions( $action ) as $right ) {
1389                         // Backwards compatibility, rewrite sysop -> protect
1390                         if ( $right == 'sysop' ) {
1391                                 $right = 'protect';
1392                         }
1393                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1394                                 // Users with 'editprotected' permission can edit protected pages
1395                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1396                                         // Users with 'editprotected' permission cannot edit protected pages
1397                                         // with cascading option turned on.
1398                                         if ( $this->mCascadeRestriction ) {
1399                                                 $errors[] = array( 'protectedpagetext', $right );
1400                                         }
1401                                 } else {
1402                                         $errors[] = array( 'protectedpagetext', $right );
1403                                 }
1404                         }
1405                 }
1406
1407                 return $errors;
1408         }
1409
1410         /**
1411          * Check restrictions on cascading pages.
1412          * @see checkQuickPermissions for parameter information
1413          */
1414         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1415                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1416                         # We /could/ use the protection level on the source page, but it's
1417                         # fairly ugly as we have to establish a precedence hierarchy for pages
1418                         # included by multiple cascade-protected pages. So just restrict
1419                         # it to people with 'protect' permission, as they could remove the
1420                         # protection anyway.
1421                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1422                         # Cascading protection depends on more than this page...
1423                         # Several cascading protected pages may include this page...
1424                         # Check each cascading level
1425                         # This is only for protection restrictions, not for all actions
1426                         if ( isset( $restrictions[$action] ) ) {
1427                                 foreach ( $restrictions[$action] as $right ) {
1428                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1429                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1430                                                 $pages = '';
1431                                                 foreach ( $cascadingSources as $page )
1432                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1433                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1434                                         }
1435                                 }
1436                         }
1437                 }
1438
1439                 return $errors;
1440         }
1441
1442         /**
1443          * Check action permissions not already checked in checkQuickPermissions
1444          * @see checkQuickPermissions for parameter information
1445          */
1446         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1447                 if ( $action == 'protect' ) {
1448                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1449                                 // If they can't edit, they shouldn't protect.
1450                                 $errors[] = array( 'protect-cantedit' );
1451                         }
1452                 } elseif ( $action == 'create' ) {
1453                         $title_protection = $this->getTitleProtection();
1454                         if( $title_protection ) {
1455                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1456                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1457                                 }
1458                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1459                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1460                                 }
1461                         }
1462                 } elseif ( $action == 'move' ) {
1463                         // Check for immobile pages
1464                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1465                                 // Specific message for this case
1466                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1467                         } elseif ( !$this->isMovable() ) {
1468                                 // Less specific message for rarer cases
1469                                 $errors[] = array( 'immobile-page' );
1470                         }
1471                 } elseif ( $action == 'move-target' ) {
1472                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1473                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1474                         } elseif ( !$this->isMovable() ) {
1475                                 $errors[] = array( 'immobile-target-page' );
1476                         }
1477                 }
1478                 return $errors;
1479         }
1480
1481         /**
1482          * Check that the user isn't blocked from editting.
1483          * @see checkQuickPermissions for parameter information
1484          */
1485         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1486                 if( $short ) {
1487                         return $errors;
1488                 }
1489
1490                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1491
1492                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1493                         $errors[] = array( 'confirmedittext' );
1494                 }
1495
1496                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1497                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1498                         $block = $user->mBlock;
1499
1500                         // This is from OutputPage::blockedPage
1501                         // Copied at r23888 by werdna
1502
1503                         $id = $user->blockedBy();
1504                         $reason = $user->blockedFor();
1505                         if ( $reason == '' ) {
1506                                 $reason = wfMsg( 'blockednoreason' );
1507                         }
1508                         $ip = wfGetIP();
1509
1510                         if ( is_numeric( $id ) ) {
1511                                 $name = User::whoIs( $id );
1512                         } else {
1513                                 $name = $id;
1514                         }
1515
1516                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1517                         $blockid = $block->mId;
1518                         $blockExpiry = $user->mBlock->mExpiry;
1519                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1520                         if ( $blockExpiry == 'infinity' ) {
1521                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1522                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1523
1524                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1525                                         if ( !strpos( $option, ':' ) )
1526                                                 continue;
1527
1528                                         list( $show, $value ) = explode( ':', $option );
1529
1530                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1531                                                 $blockExpiry = $show;
1532                                                 break;
1533                                         }
1534                                 }
1535                         } else {
1536                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1537                         }
1538
1539                         $intended = $user->mBlock->mAddress;
1540
1541                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1542                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1543                 }
1544
1545                 return $errors;
1546         }
1547
1548         /**
1549          * Can $user perform $action on this page? This is an internal function,
1550          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1551          * checks on wfReadOnly() and blocks)
1552          *
1553          * @param $action \type{\string} action that permission needs to be checked for
1554          * @param $user \type{User} user to check
1555          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1556          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1557          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1558          */
1559         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1560                 wfProfileIn( __METHOD__ );
1561
1562                 $errors = array();
1563                 $checks = array(
1564                         'checkQuickPermissions',
1565                         'checkPermissionHooks',
1566                         'checkSpecialsAndNSPermissions',
1567                         'checkCSSandJSPermissions',
1568                         'checkPageRestrictions',
1569                         'checkCascadingSourcesRestrictions',
1570                         'checkActionPermissions',
1571                         'checkUserBlock'
1572                 );
1573
1574                 while( count( $checks ) > 0 &&
1575                            !( $short && count( $errors ) > 0 ) ) {
1576                         $method = array_shift( $checks );
1577                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1578                 }
1579
1580                 wfProfileOut( __METHOD__ );
1581                 return $errors;
1582         }
1583
1584         /**
1585          * Is this title subject to title protection?
1586          *
1587          * @return \type{\mixed} An associative array representing any existent title
1588          *   protection, or false if there's none.
1589          */
1590         private function getTitleProtection() {
1591                 // Can't protect pages in special namespaces
1592                 if ( $this->getNamespace() < 0 ) {
1593                         return false;
1594                 }
1595
1596                 // Can't protect pages that exist.
1597                 if ( $this->exists() ) {
1598                         return false;
1599                 }
1600
1601                 if ( !isset( $this->mTitleProtection ) ) {
1602                         $dbr = wfGetDB( DB_SLAVE );
1603                         $res = $dbr->select( 'protected_titles', '*',
1604                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1605                                 __METHOD__ );
1606
1607                         // fetchRow returns false if there are no rows.
1608                         $this->mTitleProtection = $dbr->fetchRow( $res );
1609                 }
1610                 return $this->mTitleProtection;
1611         }
1612
1613         /**
1614          * Update the title protection status
1615          *
1616          * @param $create_perm \type{\string} Permission required for creation
1617          * @param $reason \type{\string} Reason for protection
1618          * @param $expiry \type{\string} Expiry timestamp
1619          * @return boolean true
1620          */
1621         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1622                 global $wgUser, $wgContLang;
1623
1624                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1625                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1626                         // No change
1627                         return true;
1628                 }
1629
1630                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1631
1632                 $dbw = wfGetDB( DB_MASTER );
1633
1634                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1635
1636                 $expiry_description = '';
1637                 if ( $encodedExpiry != 'infinity' ) {
1638                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1639                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1640                 } else {
1641                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1642                 }
1643
1644                 # Update protection table
1645                 if ( $create_perm != '' ) {
1646                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1647                                 array(
1648                                         'pt_namespace' => $namespace,
1649                                         'pt_title' => $title,
1650                                         'pt_create_perm' => $create_perm,
1651                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1652                                         'pt_expiry' => $encodedExpiry,
1653                                         'pt_user' => $wgUser->getId(),
1654                                         'pt_reason' => $reason,
1655                                 ), __METHOD__
1656                         );
1657                 } else {
1658                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1659                                 'pt_title' => $title ), __METHOD__ );
1660                 }
1661                 # Update the protection log
1662                 if ( $dbw->affectedRows() ) {
1663                         $log = new LogPage( 'protect' );
1664
1665                         if ( $create_perm ) {
1666                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1667                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1668                         } else {
1669                                 $log->addEntry( 'unprotect', $this, $reason );
1670                         }
1671                 }
1672
1673                 return true;
1674         }
1675
1676         /**
1677          * Remove any title protection due to page existing
1678          */
1679         public function deleteTitleProtection() {
1680                 $dbw = wfGetDB( DB_MASTER );
1681
1682                 $dbw->delete(
1683                         'protected_titles',
1684                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1685                         __METHOD__
1686                 );
1687         }
1688
1689         /**
1690          * Would anybody with sufficient privileges be able to move this page?
1691          * Some pages just aren't movable.
1692          *
1693          * @return \type{\bool} TRUE or FALSE
1694          */
1695         public function isMovable() {
1696                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1697         }
1698
1699         /**
1700          * Can $wgUser read this page?
1701          *
1702          * @return \type{\bool}
1703          * @todo fold these checks into userCan()
1704          */
1705         public function userCanRead() {
1706                 global $wgUser, $wgGroupPermissions;
1707
1708                 static $useShortcut = null;
1709
1710                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1711                 if ( is_null( $useShortcut ) ) {
1712                         global $wgRevokePermissions;
1713                         $useShortcut = true;
1714                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1715                                 # Not a public wiki, so no shortcut
1716                                 $useShortcut = false;
1717                         } elseif ( !empty( $wgRevokePermissions ) ) {
1718                                 /*
1719                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1720                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1721                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1722                                  * reading is allowed.
1723                                  */
1724                                 foreach ( $wgRevokePermissions as $perms ) {
1725                                         if ( !empty( $perms['read'] ) ) {
1726                                                 # We might be removing the read right from the user, so no shortcut
1727                                                 $useShortcut = false;
1728                                                 break;
1729                                         }
1730                                 }
1731                         }
1732                 }
1733
1734                 $result = null;
1735                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1736                 if ( $result !== null ) {
1737                         return $result;
1738                 }
1739
1740                 # Shortcut for public wikis, allows skipping quite a bit of code
1741                 if ( $useShortcut ) {
1742                         return true;
1743                 }
1744
1745                 if ( $wgUser->isAllowed( 'read' ) ) {
1746                         return true;
1747                 } else {
1748                         global $wgWhitelistRead;
1749
1750                         /**
1751                          * Always grant access to the login page.
1752                          * Even anons need to be able to log in.
1753                         */
1754                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1755                                 return true;
1756                         }
1757
1758                         /**
1759                          * Bail out if there isn't whitelist
1760                          */
1761                         if ( !is_array( $wgWhitelistRead ) ) {
1762                                 return false;
1763                         }
1764
1765                         /**
1766                          * Check for explicit whitelisting
1767                          */
1768                         $name = $this->getPrefixedText();
1769                         $dbName = $this->getPrefixedDBKey();
1770                         // Check with and without underscores
1771                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1772                                 return true;
1773
1774                         /**
1775                          * Old settings might have the title prefixed with
1776                          * a colon for main-namespace pages
1777                          */
1778                         if ( $this->getNamespace() == NS_MAIN ) {
1779                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1780                                         return true;
1781                                 }
1782                         }
1783
1784                         /**
1785                          * If it's a special page, ditch the subpage bit
1786                          * and check again
1787                          */
1788                         if ( $this->getNamespace() == NS_SPECIAL ) {
1789                                 $name = $this->getDBkey();
1790                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1791                                 if ( $name === false ) {
1792                                         # Invalid special page, but we show standard login required message
1793                                         return false;
1794                                 }
1795
1796                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1797                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1798                                         return true;
1799                                 }
1800                         }
1801
1802                 }
1803                 return false;
1804         }
1805
1806         /**
1807          * Is this a talk page of some sort?
1808          *
1809          * @return \type{\bool}
1810          */
1811         public function isTalkPage() {
1812                 return MWNamespace::isTalk( $this->getNamespace() );
1813         }
1814
1815         /**
1816          * Is this a subpage?
1817          *
1818          * @return \type{\bool}
1819          */
1820         public function isSubpage() {
1821                 return MWNamespace::hasSubpages( $this->mNamespace )
1822                         ? strpos( $this->getText(), '/' ) !== false
1823                         : false;
1824         }
1825
1826         /**
1827          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1828          *
1829          * @return \type{\bool}
1830          */
1831         public function hasSubpages() {
1832                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1833                         # Duh
1834                         return false;
1835                 }
1836
1837                 # We dynamically add a member variable for the purpose of this method
1838                 # alone to cache the result.  There's no point in having it hanging
1839                 # around uninitialized in every Title object; therefore we only add it
1840                 # if needed and don't declare it statically.
1841                 if ( isset( $this->mHasSubpages ) ) {
1842                         return $this->mHasSubpages;
1843                 }
1844
1845                 $subpages = $this->getSubpages( 1 );
1846                 if ( $subpages instanceof TitleArray ) {
1847                         return $this->mHasSubpages = (bool)$subpages->count();
1848                 }
1849                 return $this->mHasSubpages = false;
1850         }
1851
1852         /**
1853          * Get all subpages of this page.
1854          *
1855          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1856          * @return mixed TitleArray, or empty array if this page's namespace
1857          *  doesn't allow subpages
1858          */
1859         public function getSubpages( $limit = -1 ) {
1860                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1861                         return array();
1862                 }
1863
1864                 $dbr = wfGetDB( DB_SLAVE );
1865                 $conds['page_namespace'] = $this->getNamespace();
1866                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1867                 $options = array();
1868                 if ( $limit > -1 ) {
1869                         $options['LIMIT'] = $limit;
1870                 }
1871                 return $this->mSubpages = TitleArray::newFromResult(
1872                         $dbr->select( 'page',
1873                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1874                                 $conds,
1875                                 __METHOD__,
1876                                 $options
1877                         )
1878                 );
1879         }
1880
1881         /**
1882          * Could this page contain custom CSS or JavaScript, based
1883          * on the title?
1884          *
1885          * @return \type{\bool}
1886          */
1887         public function isCssOrJsPage() {
1888                 return $this->mNamespace == NS_MEDIAWIKI
1889                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1890         }
1891
1892         /**
1893          * Is this a .css or .js subpage of a user page?
1894          * @return \type{\bool}
1895          */
1896         public function isCssJsSubpage() {
1897                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1898         }
1899
1900         /**
1901          * Is this a *valid* .css or .js subpage of a user page?
1902          * Check that the corresponding skin exists
1903          *
1904          * @return \type{\bool}
1905          */
1906         public function isValidCssJsSubpage() {
1907                 if ( $this->isCssJsSubpage() ) {
1908                         $name = $this->getSkinFromCssJsSubpage();
1909                         if ( $name == 'common' ) {
1910                                 return true;
1911                         }
1912                         $skinNames = Skin::getSkinNames();
1913                         return array_key_exists( $name, $skinNames );
1914                 } else {
1915                         return false;
1916                 }
1917         }
1918
1919         /**
1920          * Trim down a .css or .js subpage title to get the corresponding skin name
1921          *
1922          * @return string containing skin name from .css or .js subpage title
1923          */
1924         public function getSkinFromCssJsSubpage() {
1925                 $subpage = explode( '/', $this->mTextform );
1926                 $subpage = $subpage[ count( $subpage ) - 1 ];
1927                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1928         }
1929
1930         /**
1931          * Is this a .css subpage of a user page?
1932          *
1933          * @return \type{\bool}
1934          */
1935         public function isCssSubpage() {
1936                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1937         }
1938
1939         /**
1940          * Is this a .js subpage of a user page?
1941          *
1942          * @return \type{\bool}
1943          */
1944         public function isJsSubpage() {
1945                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1946         }
1947
1948         /**
1949          * Protect css subpages of user pages: can $wgUser edit
1950          * this page?
1951          *
1952          * @return \type{\bool}
1953          * @todo XXX: this might be better using restrictions
1954          */
1955         public function userCanEditCssSubpage() {
1956                 global $wgUser;
1957                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1958                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1959         }
1960
1961         /**
1962          * Protect js subpages of user pages: can $wgUser edit
1963          * this page?
1964          *
1965          * @return \type{\bool}
1966          * @todo XXX: this might be better using restrictions
1967          */
1968         public function userCanEditJsSubpage() {
1969                 global $wgUser;
1970                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1971                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1972         }
1973
1974         /**
1975          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1976          *
1977          * @return \type{\bool} If the page is subject to cascading restrictions.
1978          */
1979         public function isCascadeProtected() {
1980                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1981                 return ( $sources > 0 );
1982         }
1983
1984         /**
1985          * Cascading protection: Get the source of any cascading restrictions on this page.
1986          *
1987          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1988          *        that the restrictions have come from.
1989          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1990          *         objects of the pages from which cascading restrictions have come,
1991          *         false for none, or true if such restrictions exist, but $getPages was not set.
1992          *         The restriction array is an array of each type, each of which contains a
1993          *         array of unique groups.
1994          */
1995         public function getCascadeProtectionSources( $getPages = true ) {
1996                 $pagerestrictions = array();
1997
1998                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1999                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2000                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2001                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2002                 }
2003
2004                 wfProfileIn( __METHOD__ );
2005
2006                 $dbr = wfGetDB( DB_SLAVE );
2007
2008                 if ( $this->getNamespace() == NS_FILE ) {
2009                         $tables = array( 'imagelinks', 'page_restrictions' );
2010                         $where_clauses = array(
2011                                 'il_to' => $this->getDBkey(),
2012                                 'il_from=pr_page',
2013                                 'pr_cascade' => 1
2014                         );
2015                 } else {
2016                         $tables = array( 'templatelinks', 'page_restrictions' );
2017                         $where_clauses = array(
2018                                 'tl_namespace' => $this->getNamespace(),
2019                                 'tl_title' => $this->getDBkey(),
2020                                 'tl_from=pr_page',
2021                                 'pr_cascade' => 1
2022                         );
2023                 }
2024
2025                 if ( $getPages ) {
2026                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2027                                                    'pr_expiry', 'pr_type', 'pr_level' );
2028                         $where_clauses[] = 'page_id=pr_page';
2029                         $tables[] = 'page';
2030                 } else {
2031                         $cols = array( 'pr_expiry' );
2032                 }
2033
2034                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2035
2036                 $sources = $getPages ? array() : false;
2037                 $now = wfTimestampNow();
2038                 $purgeExpired = false;
2039
2040                 foreach ( $res as $row ) {
2041                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2042                         if ( $expiry > $now ) {
2043                                 if ( $getPages ) {
2044                                         $page_id = $row->pr_page;
2045                                         $page_ns = $row->page_namespace;
2046                                         $page_title = $row->page_title;
2047                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2048                                         # Add groups needed for each restriction type if its not already there
2049                                         # Make sure this restriction type still exists
2050
2051                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2052                                                 $pagerestrictions[$row->pr_type] = array();
2053                                         }
2054
2055                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2056                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2057                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2058                                         }
2059                                 } else {
2060                                         $sources = true;
2061                                 }
2062                         } else {
2063                                 // Trigger lazy purge of expired restrictions from the db
2064                                 $purgeExpired = true;
2065                         }
2066                 }
2067                 if ( $purgeExpired ) {
2068                         Title::purgeExpiredRestrictions();
2069                 }
2070
2071                 wfProfileOut( __METHOD__ );
2072
2073                 if ( $getPages ) {
2074                         $this->mCascadeSources = $sources;
2075                         $this->mCascadingRestrictions = $pagerestrictions;
2076                 } else {
2077                         $this->mHasCascadingRestrictions = $sources;
2078                 }
2079
2080                 return array( $sources, $pagerestrictions );
2081         }
2082
2083         /**
2084          * Returns cascading restrictions for the current article
2085          *
2086          * @return Boolean
2087          */
2088         function areRestrictionsCascading() {
2089                 if ( !$this->mRestrictionsLoaded ) {
2090                         $this->loadRestrictions();
2091                 }
2092
2093                 return $this->mCascadeRestriction;
2094         }
2095
2096         /**
2097          * Loads a string into mRestrictions array
2098          *
2099          * @param $res \type{Resource} restrictions as an SQL result.
2100          * @param $oldFashionedRestrictions string comma-separated list of page
2101          *        restrictions from page table (pre 1.10)
2102          */
2103         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2104                 $rows = array();
2105
2106                 foreach ( $res as $row ) {
2107                         $rows[] = $row;
2108                 }
2109
2110                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2111         }
2112
2113         /**
2114          * Compiles list of active page restrictions from both page table (pre 1.10)
2115          * and page_restrictions table
2116          *
2117          * @param $rows array of db result objects
2118          * @param $oldFashionedRestrictions string comma-separated list of page
2119          *        restrictions from page table (pre 1.10)
2120          */
2121         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2122                 $dbr = wfGetDB( DB_SLAVE );
2123
2124                 $restrictionTypes = $this->getRestrictionTypes();
2125
2126                 foreach ( $restrictionTypes as $type ) {
2127                         $this->mRestrictions[$type] = array();
2128                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2129                 }
2130
2131                 $this->mCascadeRestriction = false;
2132
2133                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2134
2135                 if ( $oldFashionedRestrictions === null ) {
2136                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2137                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2138                 }
2139
2140                 if ( $oldFashionedRestrictions != '' ) {
2141
2142                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2143                                 $temp = explode( '=', trim( $restrict ) );
2144                                 if ( count( $temp ) == 1 ) {
2145                                         // old old format should be treated as edit/move restriction
2146                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2147                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2148                                 } else {
2149                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2150                                 }
2151                         }
2152
2153                         $this->mOldRestrictions = true;
2154
2155                 }
2156
2157                 if ( count( $rows ) ) {
2158                         # Current system - load second to make them override.
2159                         $now = wfTimestampNow();
2160                         $purgeExpired = false;
2161
2162                         foreach ( $rows as $row ) {
2163                                 # Cycle through all the restrictions.
2164
2165                                 // Don't take care of restrictions types that aren't allowed
2166
2167                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2168                                         continue;
2169
2170                                 // This code should be refactored, now that it's being used more generally,
2171                                 // But I don't really see any harm in leaving it in Block for now -werdna
2172                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2173
2174                                 // Only apply the restrictions if they haven't expired!
2175                                 if ( !$expiry || $expiry > $now ) {
2176                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2177                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2178
2179                                         $this->mCascadeRestriction |= $row->pr_cascade;
2180                                 } else {
2181                                         // Trigger a lazy purge of expired restrictions
2182                                         $purgeExpired = true;
2183                                 }
2184                         }
2185
2186                         if ( $purgeExpired ) {
2187                                 Title::purgeExpiredRestrictions();
2188                         }
2189                 }
2190
2191                 $this->mRestrictionsLoaded = true;
2192         }
2193
2194         /**
2195          * Load restrictions from the page_restrictions table
2196          *
2197          * @param $oldFashionedRestrictions string comma-separated list of page
2198          *        restrictions from page table (pre 1.10)
2199          */
2200         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2201                 if ( !$this->mRestrictionsLoaded ) {
2202                         if ( $this->exists() ) {
2203                                 $dbr = wfGetDB( DB_SLAVE );
2204
2205                                 $res = $dbr->select( 'page_restrictions', '*',
2206                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2207
2208                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2209                         } else {
2210                                 $title_protection = $this->getTitleProtection();
2211
2212                                 if ( $title_protection ) {
2213                                         $now = wfTimestampNow();
2214                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2215
2216                                         if ( !$expiry || $expiry > $now ) {
2217                                                 // Apply the restrictions
2218                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2219                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2220                                         } else { // Get rid of the old restrictions
2221                                                 Title::purgeExpiredRestrictions();
2222                                         }
2223                                 } else {
2224                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2225                                 }
2226                                 $this->mRestrictionsLoaded = true;
2227                         }
2228                 }
2229         }
2230
2231         /**
2232          * Purge expired restrictions from the page_restrictions table
2233          */
2234         static function purgeExpiredRestrictions() {
2235                 $dbw = wfGetDB( DB_MASTER );
2236                 $dbw->delete(
2237                         'page_restrictions',
2238                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2239                         __METHOD__
2240                 );
2241
2242                 $dbw->delete(
2243                         'protected_titles',
2244                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2245                         __METHOD__
2246                 );
2247         }
2248
2249         /**
2250          * Accessor/initialisation for mRestrictions
2251          *
2252          * @param $action \type{\string} action that permission needs to be checked for
2253          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2254          */
2255         public function getRestrictions( $action ) {
2256                 if ( !$this->mRestrictionsLoaded ) {
2257                         $this->loadRestrictions();
2258                 }
2259                 return isset( $this->mRestrictions[$action] )
2260                                 ? $this->mRestrictions[$action]
2261                                 : array();
2262         }
2263
2264         /**
2265          * Get the expiry time for the restriction against a given action
2266          *
2267          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2268          *      or not protected at all, or false if the action is not recognised.
2269          */
2270         public function getRestrictionExpiry( $action ) {
2271                 if ( !$this->mRestrictionsLoaded ) {
2272                         $this->loadRestrictions();
2273                 }
2274                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2275         }
2276
2277         /**
2278          * Is there a version of this page in the deletion archive?
2279          *
2280          * @return \type{\int} the number of archived revisions
2281          */
2282         public function isDeleted() {
2283                 if ( $this->getNamespace() < 0 ) {
2284                         $n = 0;
2285                 } else {
2286                         $dbr = wfGetDB( DB_SLAVE );
2287                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2288                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2289                                 __METHOD__
2290                         );
2291                         if ( $this->getNamespace() == NS_FILE ) {
2292                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2293                                         array( 'fa_name' => $this->getDBkey() ),
2294                                         __METHOD__
2295                                 );
2296                         }
2297                 }
2298                 return (int)$n;
2299         }
2300
2301         /**
2302          * Is there a version of this page in the deletion archive?
2303          *
2304          * @return Boolean
2305          */
2306         public function isDeletedQuick() {
2307                 if ( $this->getNamespace() < 0 ) {
2308                         return false;
2309                 }
2310                 $dbr = wfGetDB( DB_SLAVE );
2311                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2312                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2313                         __METHOD__
2314                 );
2315                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2316                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2317                                 array( 'fa_name' => $this->getDBkey() ),
2318                                 __METHOD__
2319                         );
2320                 }
2321                 return $deleted;
2322         }
2323
2324         /**
2325          * Get the article ID for this Title from the link cache,
2326          * adding it if necessary
2327          *
2328          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2329          *  for update
2330          * @return \type{\int} the ID
2331          */
2332         public function getArticleID( $flags = 0 ) {
2333                 if ( $this->getNamespace() < 0 ) {
2334                         return $this->mArticleID = 0;
2335                 }
2336                 $linkCache = LinkCache::singleton();
2337                 if ( $flags & self::GAID_FOR_UPDATE ) {
2338                         $oldUpdate = $linkCache->forUpdate( true );
2339                         $linkCache->clearLink( $this );
2340                         $this->mArticleID = $linkCache->addLinkObj( $this );
2341                         $linkCache->forUpdate( $oldUpdate );
2342                 } else {
2343                         if ( -1 == $this->mArticleID ) {
2344                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2345                         }
2346                 }
2347                 return $this->mArticleID;
2348         }
2349
2350         /**
2351          * Is this an article that is a redirect page?
2352          * Uses link cache, adding it if necessary
2353          *
2354          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2355          * @return \type{\bool}
2356          */
2357         public function isRedirect( $flags = 0 ) {
2358                 if ( !is_null( $this->mRedirect ) ) {
2359                         return $this->mRedirect;
2360                 }
2361                 # Calling getArticleID() loads the field from cache as needed
2362                 if ( !$this->getArticleID( $flags ) ) {
2363                         return $this->mRedirect = false;
2364                 }
2365                 $linkCache = LinkCache::singleton();
2366                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2367
2368                 return $this->mRedirect;
2369         }
2370
2371         /**
2372          * What is the length of this page?
2373          * Uses link cache, adding it if necessary
2374          *
2375          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2376          * @return \type{\bool}
2377          */
2378         public function getLength( $flags = 0 ) {
2379                 if ( $this->mLength != -1 ) {
2380                         return $this->mLength;
2381                 }
2382                 # Calling getArticleID() loads the field from cache as needed
2383                 if ( !$this->getArticleID( $flags ) ) {
2384                         return $this->mLength = 0;
2385                 }
2386                 $linkCache = LinkCache::singleton();
2387                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2388
2389                 return $this->mLength;
2390         }
2391
2392         /**
2393          * What is the page_latest field for this page?
2394          *
2395          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2396          * @return \type{\int} or 0 if the page doesn't exist
2397          */
2398         public function getLatestRevID( $flags = 0 ) {
2399                 if ( $this->mLatestID !== false ) {
2400                         return intval( $this->mLatestID );
2401                 }
2402                 # Calling getArticleID() loads the field from cache as needed
2403                 if ( !$this->getArticleID( $flags ) ) {
2404                         return $this->mLatestID = 0;
2405                 }
2406                 $linkCache = LinkCache::singleton();
2407                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2408
2409                 return $this->mLatestID;
2410         }
2411
2412         /**
2413          * This clears some fields in this object, and clears any associated
2414          * keys in the "bad links" section of the link cache.
2415          *
2416          * - This is called from Article::insertNewArticle() to allow
2417          * loading of the new page_id. It's also called from
2418          * Article::doDeleteArticle()
2419          *
2420          * @param $newid \type{\int} the new Article ID
2421          */
2422         public function resetArticleID( $newid ) {
2423                 $linkCache = LinkCache::singleton();
2424                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2425
2426                 if ( $newid === false ) {
2427                         $this->mArticleID = -1;
2428                 } else {
2429                         $this->mArticleID = intval( $newid );
2430                 }
2431                 $this->mRestrictionsLoaded = false;
2432                 $this->mRestrictions = array();
2433                 $this->mRedirect = null;
2434                 $this->mLength = -1;
2435                 $this->mLatestID = false;
2436         }
2437
2438         /**
2439          * Updates page_touched for this page; called from LinksUpdate.php
2440          *
2441          * @return \type{\bool} true if the update succeded
2442          */
2443         public function invalidateCache() {
2444                 if ( wfReadOnly() ) {
2445                         return;
2446                 }
2447                 $dbw = wfGetDB( DB_MASTER );
2448                 $success = $dbw->update(
2449                         'page',
2450                         array( 'page_touched' => $dbw->timestamp() ),
2451                         $this->pageCond(),
2452                         __METHOD__
2453                 );
2454                 HTMLFileCache::clearFileCache( $this );
2455                 return $success;
2456         }
2457
2458         /**
2459          * Prefix some arbitrary text with the namespace or interwiki prefix
2460          * of this object
2461          *
2462          * @param $name \type{\string} the text
2463          * @return \type{\string} the prefixed text
2464          * @private
2465          */
2466         /* private */ function prefix( $name ) {
2467                 $p = '';
2468                 if ( $this->mInterwiki != '' ) {
2469                         $p = $this->mInterwiki . ':';
2470                 }
2471                 if ( 0 != $this->mNamespace ) {
2472                         $p .= $this->getNsText() . ':';
2473                 }
2474                 return $p . $name;
2475         }
2476
2477         /**
2478          * Returns a simple regex that will match on characters and sequences invalid in titles.
2479          * Note that this doesn't pick up many things that could be wrong with titles, but that
2480          * replacing this regex with something valid will make many titles valid.
2481          *
2482          * @return string regex string
2483          */
2484         static function getTitleInvalidRegex() {
2485                 static $rxTc = false;
2486                 if ( !$rxTc ) {
2487                         # Matching titles will be held as illegal.
2488                         $rxTc = '/' .
2489                                 # Any character not allowed is forbidden...
2490                                 '[^' . Title::legalChars() . ']' .
2491                                 # URL percent encoding sequences interfere with the ability
2492                                 # to round-trip titles -- you can't link to them consistently.
2493                                 '|%[0-9A-Fa-f]{2}' .
2494                                 # XML/HTML character references produce similar issues.
2495                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2496                                 '|&#[0-9]+;' .
2497                                 '|&#x[0-9A-Fa-f]+;' .
2498                                 '/S';
2499                 }
2500
2501                 return $rxTc;
2502         }
2503
2504         /**
2505          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2506          *
2507          * @param $text string containing title to capitalize
2508          * @param $ns int namespace index, defaults to NS_MAIN
2509          * @return String containing capitalized title
2510          */
2511         public static function capitalize( $text, $ns = NS_MAIN ) {
2512                 global $wgContLang;
2513
2514                 if ( MWNamespace::isCapitalized( $ns ) ) {
2515                         return $wgContLang->ucfirst( $text );
2516                 } else {
2517                         return $text;
2518                 }
2519         }
2520
2521         /**
2522          * Secure and split - main initialisation function for this object
2523          *
2524          * Assumes that mDbkeyform has been set, and is urldecoded
2525          * and uses underscores, but not otherwise munged.  This function
2526          * removes illegal characters, splits off the interwiki and
2527          * namespace prefixes, sets the other forms, and canonicalizes
2528          * everything.
2529          *
2530          * @return \type{\bool} true on success
2531          */
2532         private function secureAndSplit() {
2533                 global $wgContLang, $wgLocalInterwiki;
2534
2535                 # Initialisation
2536                 $rxTc = self::getTitleInvalidRegex();
2537
2538                 $this->mInterwiki = $this->mFragment = '';
2539                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2540
2541                 $dbkey = $this->mDbkeyform;
2542
2543                 # Strip Unicode bidi override characters.
2544                 # Sometimes they slip into cut-n-pasted page titles, where the
2545                 # override chars get included in list displays.
2546                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2547
2548                 # Clean up whitespace
2549                 # Note: use of the /u option on preg_replace here will cause
2550                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2551                 # conveniently disabling them.
2552                 #
2553                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2554                 $dbkey = trim( $dbkey, '_' );
2555
2556                 if ( $dbkey == '' ) {
2557                         return false;
2558                 }
2559
2560                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2561                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2562                         return false;
2563                 }
2564
2565                 $this->mDbkeyform = $dbkey;
2566
2567                 # Initial colon indicates main namespace rather than specified default
2568                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2569                 if ( ':' == $dbkey { 0 } ) {
2570                         $this->mNamespace = NS_MAIN;
2571                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2572                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2573                 }
2574
2575                 # Namespace or interwiki prefix
2576                 $firstPass = true;
2577                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2578                 do {
2579                         $m = array();
2580                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2581                                 $p = $m[1];
2582                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2583                                         # Ordinary namespace
2584                                         $dbkey = $m[2];
2585                                         $this->mNamespace = $ns;
2586                                         # For Talk:X pages, check if X has a "namespace" prefix
2587                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2588                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2589                                                         return false; # Disallow Talk:File:x type titles...
2590                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2591                                                         return false; # Disallow Talk:Interwiki:x type titles...
2592                                                 }
2593                                         }
2594                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2595                                         if ( !$firstPass ) {
2596                                                 # Can't make a local interwiki link to an interwiki link.
2597                                                 # That's just crazy!
2598                                                 return false;
2599                                         }
2600
2601                                         # Interwiki link
2602                                         $dbkey = $m[2];
2603                                         $this->mInterwiki = $wgContLang->lc( $p );
2604
2605                                         # Redundant interwiki prefix to the local wiki
2606                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2607                                                 if ( $dbkey == '' ) {
2608                                                         # Can't have an empty self-link
2609                                                         return false;
2610                                                 }
2611                                                 $this->mInterwiki = '';
2612                                                 $firstPass = false;
2613                                                 # Do another namespace split...
2614                                                 continue;
2615                                         }
2616
2617                                         # If there's an initial colon after the interwiki, that also
2618                                         # resets the default namespace
2619                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2620                                                 $this->mNamespace = NS_MAIN;
2621                                                 $dbkey = substr( $dbkey, 1 );
2622                                         }
2623                                 }
2624                                 # If there's no recognized interwiki or namespace,
2625                                 # then let the colon expression be part of the title.
2626                         }
2627                         break;
2628                 } while ( true );
2629
2630                 # We already know that some pages won't be in the database!
2631                 #
2632                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2633                         $this->mArticleID = 0;
2634                 }
2635                 $fragment = strstr( $dbkey, '#' );
2636                 if ( false !== $fragment ) {
2637                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2638                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2639                         # remove whitespace again: prevents "Foo_bar_#"
2640                         # becoming "Foo_bar_"
2641                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2642                 }
2643
2644                 # Reject illegal characters.
2645                 #
2646                 if ( preg_match( $rxTc, $dbkey ) ) {
2647                         return false;
2648                 }
2649
2650                 /**
2651                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2652                  * reachable due to the way web browsers deal with 'relative' URLs.
2653                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2654                  */
2655                 if ( strpos( $dbkey, '.' ) !== false &&
2656                      ( $dbkey === '.' || $dbkey === '..' ||
2657                        strpos( $dbkey, './' ) === 0  ||
2658                        strpos( $dbkey, '../' ) === 0 ||
2659                        strpos( $dbkey, '/./' ) !== false ||
2660                        strpos( $dbkey, '/../' ) !== false  ||
2661                        substr( $dbkey, -2 ) == '/.' ||
2662                        substr( $dbkey, -3 ) == '/..' ) )
2663                 {
2664                         return false;
2665                 }
2666
2667                 /**
2668                  * Magic tilde sequences? Nu-uh!
2669                  */
2670                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2671                         return false;
2672                 }
2673
2674                 /**
2675                  * Limit the size of titles to 255 bytes.
2676                  * This is typically the size of the underlying database field.
2677                  * We make an exception for special pages, which don't need to be stored
2678                  * in the database, and may edge over 255 bytes due to subpage syntax
2679                  * for long titles, e.g. [[Special:Block/Long name]]
2680                  */
2681                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2682                   strlen( $dbkey ) > 512 )
2683                 {
2684                         return false;
2685                 }
2686
2687                 /**
2688                  * Normally, all wiki links are forced to have
2689                  * an initial capital letter so [[foo]] and [[Foo]]
2690                  * point to the same place.
2691                  *
2692                  * Don't force it for interwikis, since the other
2693                  * site might be case-sensitive.
2694                  */
2695                 $this->mUserCaseDBKey = $dbkey;
2696                 if ( $this->mInterwiki == '' ) {
2697                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2698                 }
2699
2700                 /**
2701                  * Can't make a link to a namespace alone...
2702                  * "empty" local links can only be self-links
2703                  * with a fragment identifier.
2704                  */
2705                 if ( $dbkey == '' &&
2706                         $this->mInterwiki == '' &&
2707                         $this->mNamespace != NS_MAIN ) {
2708                         return false;
2709                 }
2710                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2711                 // IP names are not allowed for accounts, and can only be referring to
2712                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2713                 // there are numerous ways to present the same IP. Having sp:contribs scan
2714                 // them all is silly and having some show the edits and others not is
2715                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2716                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2717                         IP::sanitizeIP( $dbkey ) : $dbkey;
2718                 // Any remaining initial :s are illegal.
2719                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2720                         return false;
2721                 }
2722
2723                 # Fill fields
2724                 $this->mDbkeyform = $dbkey;
2725                 $this->mUrlform = wfUrlencode( $dbkey );
2726
2727                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2728
2729                 return true;
2730         }
2731
2732         /**
2733          * Set the fragment for this title. Removes the first character from the
2734          * specified fragment before setting, so it assumes you're passing it with
2735          * an initial "#".
2736          *
2737          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2738          * Still in active use privately.
2739          *
2740          * @param $fragment \type{\string} text
2741          */
2742         public function setFragment( $fragment ) {
2743                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2744         }
2745
2746         /**
2747          * Get a Title object associated with the talk page of this article
2748          *
2749          * @return Title the object for the talk page
2750          */
2751         public function getTalkPage() {
2752                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2753         }
2754
2755         /**
2756          * Get a title object associated with the subject page of this
2757          * talk page
2758          *
2759          * @return Title the object for the subject page
2760          */
2761         public function getSubjectPage() {
2762                 // Is this the same title?
2763                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2764                 if ( $this->getNamespace() == $subjectNS ) {
2765                         return $this;
2766                 }
2767                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2768         }
2769
2770         /**
2771          * Get an array of Title objects linking to this Title
2772          * Also stores the IDs in the link cache.
2773          *
2774          * WARNING: do not use this function on arbitrary user-supplied titles!
2775          * On heavily-used templates it will max out the memory.
2776          *
2777          * @param $options Array: may be FOR UPDATE
2778          * @param $table String: table name
2779          * @param $prefix String: fields prefix
2780          * @return \type{\arrayof{Title}} the Title objects linking here
2781          */
2782         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2783                 $linkCache = LinkCache::singleton();
2784
2785                 if ( count( $options ) > 0 ) {
2786                         $db = wfGetDB( DB_MASTER );
2787                 } else {
2788                         $db = wfGetDB( DB_SLAVE );
2789                 }
2790
2791                 $res = $db->select(
2792                         array( 'page', $table ),
2793                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2794                         array(
2795                                 "{$prefix}_from=page_id",
2796                                 "{$prefix}_namespace" => $this->getNamespace(),
2797                                 "{$prefix}_title"     => $this->getDBkey() ),
2798                         __METHOD__,
2799                         $options
2800                 );
2801
2802                 $retVal = array();
2803                 if ( $db->numRows( $res ) ) {
2804                         foreach ( $res as $row ) {
2805                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2806                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2807                                         $retVal[] = $titleObj;
2808                                 }
2809                         }
2810                 }
2811                 return $retVal;
2812         }
2813
2814         /**
2815          * Get an array of Title objects using this Title as a template
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          * @return \type{\arrayof{Title}} the Title objects linking here
2823          */
2824         public function getTemplateLinksTo( $options = array() ) {
2825                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2826         }
2827
2828         /**
2829          * Get an array of Title objects referring to non-existent articles linked from this page
2830          *
2831          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2832          * @return \type{\arrayof{Title}} the Title objects
2833          */
2834         public function getBrokenLinksFrom() {
2835                 if ( $this->getArticleId() == 0 ) {
2836                         # All links from article ID 0 are false positives
2837                         return array();
2838                 }
2839
2840                 $dbr = wfGetDB( DB_SLAVE );
2841                 $res = $dbr->select(
2842                         array( 'page', 'pagelinks' ),
2843                         array( 'pl_namespace', 'pl_title' ),
2844                         array(
2845                                 'pl_from' => $this->getArticleId(),
2846                                 'page_namespace IS NULL'
2847                         ),
2848                         __METHOD__, array(),
2849                         array(
2850                                 'page' => array(
2851                                         'LEFT JOIN',
2852                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2853                                 )
2854                         )
2855                 );
2856
2857                 $retVal = array();
2858                 foreach ( $res as $row ) {
2859                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2860                 }
2861                 return $retVal;
2862         }
2863
2864
2865         /**
2866          * Get a list of URLs to purge from the Squid cache when this
2867          * page changes
2868          *
2869          * @return \type{\arrayof{\string}} the URLs
2870          */
2871         public function getSquidURLs() {
2872                 global $wgContLang;
2873
2874                 $urls = array(
2875                         $this->getInternalURL(),
2876                         $this->getInternalURL( 'action=history' )
2877                 );
2878
2879                 // purge variant urls as well
2880                 if ( $wgContLang->hasVariants() ) {
2881                         $variants = $wgContLang->getVariants();
2882                         foreach ( $variants as $vCode ) {
2883                                 $urls[] = $this->getInternalURL( '', $vCode );
2884                         }
2885                 }
2886
2887                 return $urls;
2888         }
2889
2890         /**
2891          * Purge all applicable Squid URLs
2892          */
2893         public function purgeSquid() {
2894                 global $wgUseSquid;
2895                 if ( $wgUseSquid ) {
2896                         $urls = $this->getSquidURLs();
2897                         $u = new SquidUpdate( $urls );
2898                         $u->doUpdate();
2899                 }
2900         }
2901
2902         /**
2903          * Move this page without authentication
2904          *
2905          * @param $nt \type{Title} the new page Title
2906          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2907          */
2908         public function moveNoAuth( &$nt ) {
2909                 return $this->moveTo( $nt, false );
2910         }
2911
2912         /**
2913          * Check whether a given move operation would be valid.
2914          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2915          *
2916          * @param $nt \type{Title} the new title
2917          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2918          *  should be checked
2919          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2920          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2921          */
2922         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2923                 global $wgUser;
2924
2925                 $errors = array();
2926                 if ( !$nt ) {
2927                         // Normally we'd add this to $errors, but we'll get
2928                         // lots of syntax errors if $nt is not an object
2929                         return array( array( 'badtitletext' ) );
2930                 }
2931                 if ( $this->equals( $nt ) ) {
2932                         $errors[] = array( 'selfmove' );
2933                 }
2934                 if ( !$this->isMovable() ) {
2935                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2936                 }
2937                 if ( $nt->getInterwiki() != '' ) {
2938                         $errors[] = array( 'immobile-target-namespace-iw' );
2939                 }
2940                 if ( !$nt->isMovable() ) {
2941                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2942                 }
2943
2944                 $oldid = $this->getArticleID();
2945                 $newid = $nt->getArticleID();
2946
2947                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2948                         $errors[] = array( 'articleexists' );
2949                 }
2950                 if ( ( $this->getDBkey() == '' ) ||
2951                          ( !$oldid ) ||
2952                      ( $nt->getDBkey() == '' ) ) {
2953                         $errors[] = array( 'badarticleerror' );
2954                 }
2955
2956                 // Image-specific checks
2957                 if ( $this->getNamespace() == NS_FILE ) {
2958                         if ( $nt->getNamespace() != NS_FILE ) {
2959                                 $errors[] = array( 'imagenocrossnamespace' );
2960                         }
2961                         $file = wfLocalFile( $this );
2962                         if ( $file->exists() ) {
2963                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2964                                         $errors[] = array( 'imageinvalidfilename' );
2965                                 }
2966                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2967                                         $errors[] = array( 'imagetypemismatch' );
2968                                 }
2969                         }
2970                         $destfile = wfLocalFile( $nt );
2971                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2972                                 $errors[] = array( 'file-exists-sharedrepo' );
2973                         }
2974                 }
2975
2976                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2977                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2978                 }
2979
2980                 if ( $auth ) {
2981                         $errors = wfMergeErrorArrays( $errors,
2982                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2983                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2984                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2985                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2986                 }
2987
2988                 $match = EditPage::matchSummarySpamRegex( $reason );
2989                 if ( $match !== false ) {
2990                         // This is kind of lame, won't display nice
2991                         $errors[] = array( 'spamprotectiontext' );
2992                 }
2993
2994                 $err = null;
2995                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2996                         $errors[] = array( 'hookaborted', $err );
2997                 }
2998
2999                 # The move is allowed only if (1) the target doesn't exist, or
3000                 # (2) the target is a redirect to the source, and has no history
3001                 # (so we can undo bad moves right after they're done).
3002
3003                 if ( 0 != $newid ) { # Target exists; check for validity
3004                         if ( !$this->isValidMoveTarget( $nt ) ) {
3005                                 $errors[] = array( 'articleexists' );
3006                         }
3007                 } else {
3008                         $tp = $nt->getTitleProtection();
3009                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3010                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3011                                 $errors[] = array( 'cantmove-titleprotected' );
3012                         }
3013                 }
3014                 if ( empty( $errors ) ) {
3015                         return true;
3016                 }
3017                 return $errors;
3018         }
3019
3020         /**
3021          * Move a title to a new location
3022          *
3023          * @param $nt \type{Title} the new title
3024          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3025          *  should be checked
3026          * @param $reason \type{\string} The reason for the move
3027          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3028          *  Ignored if the user doesn't have the suppressredirect right.
3029          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3030          */
3031         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3032                 global $wgContLang;
3033
3034                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3035                 if ( is_array( $err ) ) {
3036                         return $err;
3037                 }
3038
3039                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3040                 $dbw = wfGetDB( DB_MASTER );
3041                 if ( $this->getNamespace() == NS_FILE ) {
3042                         $file = wfLocalFile( $this );
3043                         if ( $file->exists() ) {
3044                                 $status = $file->move( $nt );
3045                                 if ( !$status->isOk() ) {
3046                                         return $status->getErrorsArray();
3047                                 }
3048                         }
3049                 }
3050
3051                 $pageid = $this->getArticleID();
3052                 $protected = $this->isProtected();
3053                 if ( $nt->exists() ) {
3054                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3055                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3056                 } else { # Target didn't exist, do normal move.
3057                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3058                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3059                 }
3060
3061                 if ( is_array( $err ) ) {
3062                         return $err;
3063                 }
3064                 $redirid = $this->getArticleID();
3065
3066                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3067                 // cl_timestamp, which may disturb time-based lists on some sites.
3068                 $prefix = $dbw->selectField(
3069                         'categorylinks',
3070                         'cl_sortkey_prefix',
3071                         array( 'cl_from' => $pageid ),
3072                         __METHOD__
3073                 );
3074                 $dbw->update( 'categorylinks',
3075                         array(
3076                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3077                                 'cl_timestamp=cl_timestamp' ),
3078                         array( 'cl_from' => $pageid ),
3079                         __METHOD__ );
3080
3081                 if ( $protected ) {
3082                         # Protect the redirect title as the title used to be...
3083                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3084                                 array(
3085                                         'pr_page'    => $redirid,
3086                                         'pr_type'    => 'pr_type',
3087                                         'pr_level'   => 'pr_level',
3088                                         'pr_cascade' => 'pr_cascade',
3089                                         'pr_user'    => 'pr_user',
3090                                         'pr_expiry'  => 'pr_expiry'
3091                                 ),
3092                                 array( 'pr_page' => $pageid ),
3093                                 __METHOD__,
3094                                 array( 'IGNORE' )
3095                         );
3096                         # Update the protection log
3097                         $log = new LogPage( 'protect' );
3098                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3099                         if ( $reason ) {
3100                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3101                         }
3102                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3103                 }
3104
3105                 # Update watchlists
3106                 $oldnamespace = $this->getNamespace() & ~1;
3107                 $newnamespace = $nt->getNamespace() & ~1;
3108                 $oldtitle = $this->getDBkey();
3109                 $newtitle = $nt->getDBkey();
3110
3111                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3112                         WatchedItem::duplicateEntries( $this, $nt );
3113                 }
3114
3115                 # Update search engine
3116                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3117                 $u->doUpdate();
3118                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3119                 $u->doUpdate();
3120
3121                 # Update site_stats
3122                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3123                         # No longer a content page
3124                         # Not viewed, edited, removing
3125                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3126                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3127                         # Now a content page
3128                         # Not viewed, edited, adding
3129                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3130                 } elseif ( $pageCountChange ) {
3131                         # Redirect added
3132                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3133                 } else {
3134                         # Nothing special
3135                         $u = false;
3136                 }
3137                 if ( $u ) {
3138                         $u->doUpdate();
3139                 }
3140                 # Update message cache for interface messages
3141                 global $wgMessageCache;
3142                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3143                         # @bug 17860: old article can be deleted, if this the case,
3144                         # delete it from message cache
3145                         if ( $this->getArticleID() === 0 ) {
3146                                 $wgMessageCache->replace( $this->getDBkey(), false );
3147                         } else {
3148                                 $oldarticle = new Article( $this );
3149                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3150                         }
3151                 }
3152                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3153                         $newarticle = new Article( $nt );
3154                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3155                 }
3156
3157                 global $wgUser;
3158                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3159                 return true;
3160         }
3161
3162         /**
3163          * Move page to a title which is at present a redirect to the
3164          * source page
3165          *
3166          * @param $nt \type{Title} the page to move to, which should currently
3167          *  be a redirect
3168          * @param $reason \type{\string} The reason for the move
3169          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3170          *  Ignored if the user doesn't have the suppressredirect right
3171          */
3172         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3173                 global $wgUseSquid, $wgUser, $wgContLang;
3174
3175                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3176
3177                 if ( $reason ) {
3178                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3179                 }
3180                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3181                 $comment = $wgContLang->truncate( $comment, 250 );
3182
3183                 $now = wfTimestampNow();
3184                 $newid = $nt->getArticleID();
3185                 $oldid = $this->getArticleID();
3186                 $latest = $this->getLatestRevID();
3187
3188                 $dbw = wfGetDB( DB_MASTER );
3189
3190                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3191                 $newns = $nt->getNamespace();
3192                 $newdbk = $nt->getDBkey();
3193
3194                 # Delete the old redirect. We don't save it to history since
3195                 # by definition if we've got here it's rather uninteresting.
3196                 # We have to remove it so that the next step doesn't trigger
3197                 # a conflict on the unique namespace+title index...
3198                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3199                 if ( !$dbw->cascadingDeletes() ) {
3200                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3201                         global $wgUseTrackbacks;
3202                         if ( $wgUseTrackbacks ) {
3203                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3204                         }
3205                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3206                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3207                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3208                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3209                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3210                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3211                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3212                 }
3213                 // If the redirect was recently created, it may have an entry in recentchanges still
3214                 $dbw->delete( 'recentchanges',
3215                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3216                         __METHOD__
3217                 );
3218
3219                 # Save a null revision in the page's history notifying of the move
3220                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3221                 $nullRevId = $nullRevision->insertOn( $dbw );
3222
3223                 $article = new Article( $this );
3224                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3225
3226                 # Change the name of the target page:
3227                 $dbw->update( 'page',
3228                         /* SET */ array(
3229                                 'page_touched'   => $dbw->timestamp( $now ),
3230                                 'page_namespace' => $nt->getNamespace(),
3231                                 'page_title'     => $nt->getDBkey(),
3232                                 'page_latest'    => $nullRevId,
3233                         ),
3234                         /* WHERE */ array( 'page_id' => $oldid ),
3235                         __METHOD__
3236                 );
3237                 $nt->resetArticleID( $oldid );
3238
3239                 # Recreate the redirect, this time in the other direction.
3240                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3241                         $mwRedir = MagicWord::get( 'redirect' );
3242                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3243                         $redirectArticle = new Article( $this );
3244                         $newid = $redirectArticle->insertOn( $dbw );
3245                         $redirectRevision = new Revision( array(
3246                                 'page'    => $newid,
3247                                 'comment' => $comment,
3248                                 'text'    => $redirectText ) );
3249                         $redirectRevision->insertOn( $dbw );
3250                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3251
3252                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3253
3254                         # Now, we record the link from the redirect to the new title.
3255                         # It should have no other outgoing links...
3256                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3257                         $dbw->insert( 'pagelinks',
3258                                 array(
3259                                         'pl_from'      => $newid,
3260                                         'pl_namespace' => $nt->getNamespace(),
3261                                         'pl_title'     => $nt->getDBkey() ),
3262                                 __METHOD__ );
3263                         $redirectSuppressed = false;
3264                 } else {
3265                         $this->resetArticleID( 0 );
3266                         $redirectSuppressed = true;
3267                 }
3268
3269                 # Log the move
3270                 $log = new LogPage( 'move' );
3271                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3272
3273                 # Purge squid
3274                 if ( $wgUseSquid ) {
3275                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3276                         $u = new SquidUpdate( $urls );
3277                         $u->doUpdate();
3278                 }
3279
3280         }
3281
3282         /**
3283          * Move page to non-existing title.
3284          *
3285          * @param $nt \type{Title} the new Title
3286          * @param $reason \type{\string} The reason for the move
3287          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3288          *  Ignored if the user doesn't have the suppressredirect right
3289          */
3290         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3291                 global $wgUser, $wgContLang;
3292
3293                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3294                 if ( $reason ) {
3295                         $comment .= wfMsgExt( 'colon-separator',
3296                                 array( 'escapenoentities', 'content' ) );
3297                         $comment .= $reason;
3298                 }
3299                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3300                 $comment = $wgContLang->truncate( $comment, 250 );
3301
3302                 $newid = $nt->getArticleID();
3303                 $oldid = $this->getArticleID();
3304                 $latest = $this->getLatestRevId();
3305
3306                 $dbw = wfGetDB( DB_MASTER );
3307                 $now = $dbw->timestamp();
3308
3309                 # Save a null revision in the page's history notifying of the move
3310                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3311                 if ( !is_object( $nullRevision ) ) {
3312                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3313                 }
3314                 $nullRevId = $nullRevision->insertOn( $dbw );
3315
3316                 $article = new Article( $this );
3317                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3318
3319                 # Rename page entry
3320                 $dbw->update( 'page',
3321                         /* SET */ array(
3322                                 'page_touched'   => $now,
3323                                 'page_namespace' => $nt->getNamespace(),
3324                                 'page_title'     => $nt->getDBkey(),
3325                                 'page_latest'    => $nullRevId,
3326                         ),
3327                         /* WHERE */ array( 'page_id' => $oldid ),
3328                         __METHOD__
3329                 );
3330                 $nt->resetArticleID( $oldid );
3331
3332                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3333                         # Insert redirect
3334                         $mwRedir = MagicWord::get( 'redirect' );
3335                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3336                         $redirectArticle = new Article( $this );
3337                         $newid = $redirectArticle->insertOn( $dbw );
3338                         $redirectRevision = new Revision( array(
3339                                 'page'    => $newid,
3340                                 'comment' => $comment,
3341                                 'text'    => $redirectText ) );
3342                         $redirectRevision->insertOn( $dbw );
3343                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3344
3345                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3346
3347                         # Record the just-created redirect's linking to the page
3348                         $dbw->insert( 'pagelinks',
3349                                 array(
3350                                         'pl_from'      => $newid,
3351                                         'pl_namespace' => $nt->getNamespace(),
3352                                         'pl_title'     => $nt->getDBkey() ),
3353                                 __METHOD__ );
3354                         $redirectSuppressed = false;
3355                 } else {
3356                         $this->resetArticleID( 0 );
3357                         $redirectSuppressed = true;
3358                 }
3359
3360                 # Log the move
3361                 $log = new LogPage( 'move' );
3362                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3363
3364                 # Purge caches as per article creation
3365                 Article::onArticleCreate( $nt );
3366
3367                 # Purge old title from squid
3368                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3369                 $this->purgeSquid();
3370         }
3371
3372         /**
3373          * Move this page's subpages to be subpages of $nt
3374          *
3375          * @param $nt Title Move target
3376          * @param $auth bool Whether $wgUser's permissions should be checked
3377          * @param $reason string The reason for the move
3378          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3379          *  Ignored if the user doesn't have the 'suppressredirect' right
3380          * @return mixed array with old page titles as keys, and strings (new page titles) or
3381          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3382          */
3383         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3384                 global $wgMaximumMovedPages;
3385                 // Check permissions
3386                 if ( !$this->userCan( 'move-subpages' ) ) {
3387                         return array( 'cant-move-subpages' );
3388                 }
3389                 // Do the source and target namespaces support subpages?
3390                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3391                         return array( 'namespace-nosubpages',
3392                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3393                 }
3394                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3395                         return array( 'namespace-nosubpages',
3396                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3397                 }
3398
3399                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3400                 $retval = array();
3401                 $count = 0;
3402                 foreach ( $subpages as $oldSubpage ) {
3403                         $count++;
3404                         if ( $count > $wgMaximumMovedPages ) {
3405                                 $retval[$oldSubpage->getPrefixedTitle()] =
3406                                                 array( 'movepage-max-pages',
3407                                                         $wgMaximumMovedPages );
3408                                 break;
3409                         }
3410
3411                         // We don't know whether this function was called before
3412                         // or after moving the root page, so check both
3413                         // $this and $nt
3414                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3415                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3416                         {
3417                                 // When moving a page to a subpage of itself,
3418                                 // don't move it twice
3419                                 continue;
3420                         }
3421                         $newPageName = preg_replace(
3422                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3423                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3424                                         $oldSubpage->getDBkey() );
3425                         if ( $oldSubpage->isTalkPage() ) {
3426                                 $newNs = $nt->getTalkPage()->getNamespace();
3427                         } else {
3428                                 $newNs = $nt->getSubjectPage()->getNamespace();
3429                         }
3430                         # Bug 14385: we need makeTitleSafe because the new page names may
3431                         # be longer than 255 characters.
3432                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3433
3434                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3435                         if ( $success === true ) {
3436                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3437                         } else {
3438                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3439                         }
3440                 }
3441                 return $retval;
3442         }
3443
3444         /**
3445          * Checks if this page is just a one-rev redirect.
3446          * Adds lock, so don't use just for light purposes.
3447          *
3448          * @return \type{\bool}
3449          */
3450         public function isSingleRevRedirect() {
3451                 $dbw = wfGetDB( DB_MASTER );
3452                 # Is it a redirect?
3453                 $row = $dbw->selectRow( 'page',
3454                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3455                         $this->pageCond(),
3456                         __METHOD__,
3457                         array( 'FOR UPDATE' )
3458                 );
3459                 # Cache some fields we may want
3460                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3461                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3462                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3463                 if ( !$this->mRedirect ) {
3464                         return false;
3465                 }
3466                 # Does the article have a history?
3467                 $row = $dbw->selectField( array( 'page', 'revision' ),
3468                         'rev_id',
3469                         array( 'page_namespace' => $this->getNamespace(),
3470                                 'page_title' => $this->getDBkey(),
3471                                 'page_id=rev_page',
3472                                 'page_latest != rev_id'
3473                         ),
3474                         __METHOD__,
3475                         array( 'FOR UPDATE' )
3476                 );
3477                 # Return true if there was no history
3478                 return ( $row === false );
3479         }
3480
3481         /**
3482          * Checks if $this can be moved to a given Title
3483          * - Selects for update, so don't call it unless you mean business
3484          *
3485          * @param $nt \type{Title} the new title to check
3486          * @return \type{\bool} TRUE or FALSE
3487          */
3488         public function isValidMoveTarget( $nt ) {
3489                 # Is it an existing file?
3490                 if ( $nt->getNamespace() == NS_FILE ) {
3491                         $file = wfLocalFile( $nt );
3492                         if ( $file->exists() ) {
3493                                 wfDebug( __METHOD__ . ": file exists\n" );
3494                                 return false;
3495                         }
3496                 }
3497                 # Is it a redirect with no history?
3498                 if ( !$nt->isSingleRevRedirect() ) {
3499                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3500                         return false;
3501                 }
3502                 # Get the article text
3503                 $rev = Revision::newFromTitle( $nt );
3504                 $text = $rev->getText();
3505                 # Does the redirect point to the source?
3506                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3507                 $m = array();
3508                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3509                         $redirTitle = Title::newFromText( $m[1] );
3510                         if ( !is_object( $redirTitle ) ||
3511                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3512                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3513                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3514                                 return false;
3515                         }
3516                 } else {
3517                         # Fail safe
3518                         wfDebug( __METHOD__ . ": failsafe\n" );
3519                         return false;
3520                 }
3521                 return true;
3522         }
3523
3524         /**
3525          * Can this title be added to a user's watchlist?
3526          *
3527          * @return \type{\bool} TRUE or FALSE
3528          */
3529         public function isWatchable() {
3530                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3531         }
3532
3533         /**
3534          * Get categories to which this Title belongs and return an array of
3535          * categories' names.
3536          *
3537          * @return \type{\array} array an array of parents in the form:
3538          *      $parent => $currentarticle
3539          */
3540         public function getParentCategories() {
3541                 global $wgContLang;
3542
3543                 $titlekey = $this->getArticleId();
3544                 $dbr = wfGetDB( DB_SLAVE );
3545                 $categorylinks = $dbr->tableName( 'categorylinks' );
3546
3547                 # NEW SQL
3548                 $sql = "SELECT * FROM $categorylinks"
3549                      . " WHERE cl_from='$titlekey'"
3550                          . " AND cl_from <> '0'"
3551                          . " ORDER BY cl_sortkey";
3552
3553                 $res = $dbr->query( $sql );
3554                 $data = array();
3555
3556                 if ( $dbr->numRows( $res ) > 0 ) {
3557                         foreach ( $res as $row ) {
3558                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3559                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3560                         }
3561                 }
3562                 return $data;
3563         }
3564
3565         /**
3566          * Get a tree of parent categories
3567          *
3568          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3569          * @return \type{\array} Tree of parent categories
3570          */
3571         public function getParentCategoryTree( $children = array() ) {
3572                 $stack = array();
3573                 $parents = $this->getParentCategories();
3574
3575                 if ( $parents ) {
3576                         foreach ( $parents as $parent => $current ) {
3577                                 if ( array_key_exists( $parent, $children ) ) {
3578                                         # Circular reference
3579                                         $stack[$parent] = array();
3580                                 } else {
3581                                         $nt = Title::newFromText( $parent );
3582                                         if ( $nt ) {
3583                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3584                                         }
3585                                 }
3586                         }
3587                 }
3588
3589                 return $stack;
3590         }
3591
3592
3593         /**
3594          * Get an associative array for selecting this title from
3595          * the "page" table
3596          *
3597          * @return \type{\array} Selection array
3598          */
3599         public function pageCond() {
3600                 if ( $this->mArticleID > 0 ) {
3601                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3602                         return array( 'page_id' => $this->mArticleID );
3603                 } else {
3604                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3605                 }
3606         }
3607
3608         /**
3609          * Get the revision ID of the previous revision
3610          *
3611          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3612          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3613          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3614          */
3615         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3616                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3617                 return $db->selectField( 'revision', 'rev_id',
3618                         array(
3619                                 'rev_page' => $this->getArticleId( $flags ),
3620                                 'rev_id < ' . intval( $revId )
3621                         ),
3622                         __METHOD__,
3623                         array( 'ORDER BY' => 'rev_id DESC' )
3624                 );
3625         }
3626
3627         /**
3628          * Get the revision ID of the next revision
3629          *
3630          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3631          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3632          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3633          */
3634         public function getNextRevisionID( $revId, $flags = 0 ) {
3635                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3636                 return $db->selectField( 'revision', 'rev_id',
3637                         array(
3638                                 'rev_page' => $this->getArticleId( $flags ),
3639                                 'rev_id > ' . intval( $revId )
3640                         ),
3641                         __METHOD__,
3642                         array( 'ORDER BY' => 'rev_id' )
3643                 );
3644         }
3645
3646         /**
3647          * Get the first revision of the page
3648          *
3649          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3650          * @return Revision (or NULL if page doesn't exist)
3651          */
3652         public function getFirstRevision( $flags = 0 ) {
3653                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3654                 $pageId = $this->getArticleId( $flags );
3655                 if ( !$pageId ) {
3656                         return null;
3657                 }
3658                 $row = $db->selectRow( 'revision', '*',
3659                         array( 'rev_page' => $pageId ),
3660                         __METHOD__,
3661                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3662                 );
3663                 if ( !$row ) {
3664                         return null;
3665                 } else {
3666                         return new Revision( $row );
3667                 }
3668         }
3669
3670         /**
3671          * Check if this is a new page
3672          *
3673          * @return bool
3674          */
3675         public function isNewPage() {
3676                 $dbr = wfGetDB( DB_SLAVE );
3677                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3678         }
3679
3680         /**
3681          * Get the oldest revision timestamp of this page
3682          *
3683          * @return String: MW timestamp
3684          */
3685         public function getEarliestRevTime() {
3686                 $dbr = wfGetDB( DB_SLAVE );
3687                 if ( $this->exists() ) {
3688                         $min = $dbr->selectField( 'revision',
3689                                 'MIN(rev_timestamp)',
3690                                 array( 'rev_page' => $this->getArticleId() ),
3691                                 __METHOD__ );
3692                         return wfTimestampOrNull( TS_MW, $min );
3693                 }
3694                 return null;
3695         }
3696
3697         /**
3698          * Get the number of revisions between the given revision IDs.
3699          * Used for diffs and other things that really need it.
3700          *
3701          * @param $old \type{\int} Revision ID.
3702          * @param $new \type{\int} Revision ID.
3703          * @return \type{\int} Number of revisions between these IDs.
3704          */
3705         public function countRevisionsBetween( $old, $new ) {
3706                 $dbr = wfGetDB( DB_SLAVE );
3707                 return (int)$dbr->selectField( 'revision', 'count(*)',
3708                         'rev_page = ' . intval( $this->getArticleId() ) .
3709                         ' AND rev_id > ' . intval( $old ) .
3710                         ' AND rev_id < ' . intval( $new ),
3711                         __METHOD__
3712                 );
3713         }
3714
3715         /**
3716          * Compare with another title.
3717          *
3718          * @param $title \type{Title}
3719          * @return \type{\bool} TRUE or FALSE
3720          */
3721         public function equals( Title $title ) {
3722                 // Note: === is necessary for proper matching of number-like titles.
3723                 return $this->getInterwiki() === $title->getInterwiki()
3724                         && $this->getNamespace() == $title->getNamespace()
3725                         && $this->getDBkey() === $title->getDBkey();
3726         }
3727
3728         /**
3729          * Callback for usort() to do title sorts by (namespace, title)
3730          *
3731          * @return Integer: result of string comparison, or namespace comparison
3732          */
3733         public static function compare( $a, $b ) {
3734                 if ( $a->getNamespace() == $b->getNamespace() ) {
3735                         return strcmp( $a->getText(), $b->getText() );
3736                 } else {
3737                         return $a->getNamespace() - $b->getNamespace();
3738                 }
3739         }
3740
3741         /**
3742          * Return a string representation of this title
3743          *
3744          * @return \type{\string} String representation of this title
3745          */
3746         public function __toString() {
3747                 return $this->getPrefixedText();
3748         }
3749
3750         /**
3751          * Check if page exists.  For historical reasons, this function simply
3752          * checks for the existence of the title in the page table, and will
3753          * thus return false for interwiki links, special pages and the like.
3754          * If you want to know if a title can be meaningfully viewed, you should
3755          * probably call the isKnown() method instead.
3756          *
3757          * @return \type{\bool}
3758          */
3759         public function exists() {
3760                 return $this->getArticleId() != 0;
3761         }
3762
3763         /**
3764          * Should links to this title be shown as potentially viewable (i.e. as
3765          * "bluelinks"), even if there's no record by this title in the page
3766          * table?
3767          *
3768          * This function is semi-deprecated for public use, as well as somewhat
3769          * misleadingly named.  You probably just want to call isKnown(), which
3770          * calls this function internally.
3771          *
3772          * (ISSUE: Most of these checks are cheap, but the file existence check
3773          * can potentially be quite expensive.  Including it here fixes a lot of
3774          * existing code, but we might want to add an optional parameter to skip
3775          * it and any other expensive checks.)
3776          *
3777          * @return \type{\bool}
3778          */
3779         public function isAlwaysKnown() {
3780                 if ( $this->mInterwiki != '' ) {
3781                         return true;  // any interwiki link might be viewable, for all we know
3782                 }
3783                 switch( $this->mNamespace ) {
3784                         case NS_MEDIA:
3785                         case NS_FILE:
3786                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3787                         case NS_SPECIAL:
3788                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3789                         case NS_MAIN:
3790                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3791                         case NS_MEDIAWIKI:
3792                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3793                                 // the full l10n of that language to be loaded. That takes much memory and
3794                                 // isn't needed. So we strip the language part away.
3795                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3796                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3797                         default:
3798                                 return false;
3799                 }
3800         }
3801
3802         /**
3803          * Does this title refer to a page that can (or might) be meaningfully
3804          * viewed?  In particular, this function may be used to determine if
3805          * links to the title should be rendered as "bluelinks" (as opposed to
3806          * "redlinks" to non-existent pages).
3807          *
3808          * @return \type{\bool}
3809          */
3810         public function isKnown() {
3811                 return $this->isAlwaysKnown() || $this->exists();
3812         }
3813
3814         /**
3815          * Does this page have source text?
3816          *
3817          * @return Boolean
3818          */
3819         public function hasSourceText() {
3820                 if ( $this->exists() ) {
3821                         return true;
3822                 }
3823
3824                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3825                         // If the page doesn't exist but is a known system message, default
3826                         // message content will be displayed, same for language subpages
3827                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3828                         // causes the full l10n of that language to be loaded. That takes much
3829                         // memory and isn't needed. So we strip the language part away.
3830                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3831                         return (bool)wfMsgWeirdKey( $basename );
3832                 }
3833
3834                 return false;
3835         }
3836
3837         /**
3838          * Is this in a namespace that allows actual pages?
3839          *
3840          * @return \type{\bool}
3841          * @internal note -- uses hardcoded namespace index instead of constants
3842          */
3843         public function canExist() {
3844                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3845         }
3846
3847         /**
3848          * Update page_touched timestamps and send squid purge messages for
3849          * pages linking to this title. May be sent to the job queue depending
3850          * on the number of links. Typically called on create and delete.
3851          */
3852         public function touchLinks() {
3853                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3854                 $u->doUpdate();
3855
3856                 if ( $this->getNamespace() == NS_CATEGORY ) {
3857                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3858                         $u->doUpdate();
3859                 }
3860         }
3861
3862         /**
3863          * Get the last touched timestamp
3864          *
3865          * @param $db DatabaseBase: optional db
3866          * @return \type{\string} Last touched timestamp
3867          */
3868         public function getTouched( $db = null ) {
3869                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3870                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3871                 return $touched;
3872         }
3873
3874         /**
3875          * Get the timestamp when this page was updated since the user last saw it.
3876          *
3877          * @param $user User
3878          * @return Mixed: string/null
3879          */
3880         public function getNotificationTimestamp( $user = null ) {
3881                 global $wgUser, $wgShowUpdatedMarker;
3882                 // Assume current user if none given
3883                 if ( !$user ) {
3884                         $user = $wgUser;
3885                 }
3886                 // Check cache first
3887                 $uid = $user->getId();
3888                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3889                         return $this->mNotificationTimestamp[$uid];
3890                 }
3891                 if ( !$uid || !$wgShowUpdatedMarker ) {
3892                         return $this->mNotificationTimestamp[$uid] = false;
3893                 }
3894                 // Don't cache too much!
3895                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3896                         $this->mNotificationTimestamp = array();
3897                 }
3898                 $dbr = wfGetDB( DB_SLAVE );
3899                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3900                         'wl_notificationtimestamp',
3901                         array( 'wl_namespace' => $this->getNamespace(),
3902                                 'wl_title' => $this->getDBkey(),
3903                                 'wl_user' => $user->getId()
3904                         ),
3905                         __METHOD__
3906                 );
3907                 return $this->mNotificationTimestamp[$uid];
3908         }
3909
3910         /**
3911          * Get the trackback URL for this page
3912          *
3913          * @return \type{\string} Trackback URL
3914          */
3915         public function trackbackURL() {
3916                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3917
3918                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3919                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3920         }
3921
3922         /**
3923          * Get the trackback RDF for this page
3924          *
3925          * @return \type{\string} Trackback RDF
3926          */
3927         public function trackbackRDF() {
3928                 $url = htmlspecialchars( $this->getFullURL() );
3929                 $title = htmlspecialchars( $this->getText() );
3930                 $tburl = $this->trackbackURL();
3931
3932                 // Autodiscovery RDF is placed in comments so HTML validator
3933                 // won't barf. This is a rather icky workaround, but seems
3934                 // frequently used by this kind of RDF thingy.
3935                 //
3936                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3937                 return "<!--
3938 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3939          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3940          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3941 <rdf:Description
3942    rdf:about=\"$url\"
3943    dc:identifier=\"$url\"
3944    dc:title=\"$title\"
3945    trackback:ping=\"$tburl\" />
3946 </rdf:RDF>
3947 -->";
3948         }
3949
3950         /**
3951          * Generate strings used for xml 'id' names in monobook tabs
3952          *
3953          * @param $prepend string defaults to 'nstab-'
3954          * @return \type{\string} XML 'id' name
3955          */
3956         public function getNamespaceKey( $prepend = 'nstab-' ) {
3957                 global $wgContLang;
3958                 // Gets the subject namespace if this title
3959                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3960                 // Checks if cononical namespace name exists for namespace
3961                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3962                         // Uses canonical namespace name
3963                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3964                 } else {
3965                         // Uses text of namespace
3966                         $namespaceKey = $this->getSubjectNsText();
3967                 }
3968                 // Makes namespace key lowercase
3969                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3970                 // Uses main
3971                 if ( $namespaceKey == '' ) {
3972                         $namespaceKey = 'main';
3973                 }
3974                 // Changes file to image for backwards compatibility
3975                 if ( $namespaceKey == 'file' ) {
3976                         $namespaceKey = 'image';
3977                 }
3978                 return $prepend . $namespaceKey;
3979         }
3980
3981         /**
3982          * Returns true if this is a special page.
3983          *
3984          * @return boolean
3985          */
3986         public function isSpecialPage() {
3987                 return $this->getNamespace() == NS_SPECIAL;
3988         }
3989
3990         /**
3991          * Returns true if this title resolves to the named special page
3992          *
3993          * @param $name \type{\string} The special page name
3994          * @return boolean
3995          */
3996         public function isSpecial( $name ) {
3997                 if ( $this->getNamespace() == NS_SPECIAL ) {
3998                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3999                         if ( $name == $thisName ) {
4000                                 return true;
4001                         }
4002                 }
4003                 return false;
4004         }
4005
4006         /**
4007          * If the Title refers to a special page alias which is not the local default,
4008          *
4009          * @return \type{Title} A new Title which points to the local default.
4010          *         Otherwise, returns $this.
4011          */
4012         public function fixSpecialName() {
4013                 if ( $this->getNamespace() == NS_SPECIAL ) {
4014                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4015                         if ( $canonicalName ) {
4016                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4017                                 if ( $localName != $this->mDbkeyform ) {
4018                                         return Title::makeTitle( NS_SPECIAL, $localName );
4019                                 }
4020                         }
4021                 }
4022                 return $this;
4023         }
4024
4025         /**
4026          * Is this Title in a namespace which contains content?
4027          * In other words, is this a content page, for the purposes of calculating
4028          * statistics, etc?
4029          *
4030          * @return \type{\bool}
4031          */
4032         public function isContentPage() {
4033                 return MWNamespace::isContent( $this->getNamespace() );
4034         }
4035
4036         /**
4037          * Get all extant redirects to this Title
4038          *
4039          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4040          *            NULL to consider all namespaces
4041          * @return \type{\arrayof{Title}} Redirects to this title
4042          */
4043         public function getRedirectsHere( $ns = null ) {
4044                 $redirs = array();
4045
4046                 $dbr = wfGetDB( DB_SLAVE );
4047                 $where = array(
4048                         'rd_namespace' => $this->getNamespace(),
4049                         'rd_title' => $this->getDBkey(),
4050                         'rd_from = page_id'
4051                 );
4052                 if ( !is_null( $ns ) ) {
4053                         $where['page_namespace'] = $ns;
4054                 }
4055
4056                 $res = $dbr->select(
4057                         array( 'redirect', 'page' ),
4058                         array( 'page_namespace', 'page_title' ),
4059                         $where,
4060                         __METHOD__
4061                 );
4062
4063                 foreach ( $res as $row ) {
4064                         $redirs[] = self::newFromRow( $row );
4065                 }
4066                 return $redirs;
4067         }
4068
4069         /**
4070          * Check if this Title is a valid redirect target
4071          *
4072          * @return \type{\bool}
4073          */
4074         public function isValidRedirectTarget() {
4075                 global $wgInvalidRedirectTargets;
4076
4077                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4078                 if ( $this->isSpecial( 'Userlogout' ) ) {
4079                         return false;
4080                 }
4081
4082                 foreach ( $wgInvalidRedirectTargets as $target ) {
4083                         if ( $this->isSpecial( $target ) ) {
4084                                 return false;
4085                         }
4086                 }
4087
4088                 return true;
4089         }
4090
4091         /**
4092          * Get a backlink cache object
4093          *
4094          * @return object BacklinkCache
4095          */
4096         function getBacklinkCache() {
4097                 if ( is_null( $this->mBacklinkCache ) ) {
4098                         $this->mBacklinkCache = new BacklinkCache( $this );
4099                 }
4100                 return $this->mBacklinkCache;
4101         }
4102
4103         /**
4104          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4105          * this page.
4106          *
4107          * @return Boolean
4108          */
4109         public function canUseNoindex() {
4110                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4111
4112                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4113                         ? $wgContentNamespaces
4114                         : $wgExemptFromUserRobotsControl;
4115
4116                 return !in_array( $this->mNamespace, $bannedNamespaces );
4117
4118         }
4119
4120         /**
4121          * Returns restriction types for the current Title
4122          *
4123          * @return array applicable restriction types
4124          */
4125         public function getRestrictionTypes() {
4126                 global $wgRestrictionTypes;
4127                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4128
4129                 if ( $this->getNamespace() == NS_FILE ) {
4130                         $types[] = 'upload';
4131                 }
4132
4133                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4134
4135                 return $types;
4136         }
4137
4138         /**
4139          * Returns the raw sort key to be used for categories, with the specified
4140          * prefix.  This will be fed to Language::convertToSortkey() to get a
4141          * binary sortkey that can be used for actual sorting.
4142          *
4143          * @param $prefix string The prefix to be used, specified using
4144          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4145          *   prefix.
4146          * @return string
4147          */
4148         public function getCategorySortkey( $prefix = '' ) {
4149                 $unprefixed = $this->getText();
4150                 if ( $prefix !== '' ) {
4151                         # Separate with a null byte, so the unprefixed part is only used as
4152                         # a tiebreaker when two pages have the exact same prefix -- null
4153                         # sorts before everything else (hopefully).
4154                         return "$prefix\0$unprefixed";
4155                 }
4156                 return $unprefixed;
4157         }
4158 }