includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  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 $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  67         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  68         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  69         var $mOldRestrictions = false;
  70         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  71         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  72         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  73         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  74         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  75         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  76         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  77         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  78         # Don't change the following default, NS_MAIN is hardcoded in several
  79         # places.  See bug 696.
  80         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  81                                                                           # Zero except in {{transclusion}} tags
  82         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  83         var $mLength = -1;                // /< The page length, 0 for special pages
  84         var $mRedirect = null;            // /< Is the article at this title a redirect?
  85         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  86         var $mBacklinkCache = null;       // /< Cache of links to this title
  87         // @}
  88
  89
  90         /**
  91          * Constructor
  92          */
  93         /*protected*/ function __construct() { }
  94
  95         /**
  96          * Create a new Title from a prefixed DB key
  97          *
  98          * @param $key String the database key, which has underscores
  99          *      instead of spaces, possibly including namespace and
 100          *      interwiki prefixes
 101          * @return Title, or NULL on an error
 102          */
 103         public static function newFromDBkey( $key ) {
 104                 $t = new Title();
 105                 $t->mDbkeyform = $key;
 106                 if ( $t->secureAndSplit() ) {
 107                         return $t;
 108                 } else {
 109                         return null;
 110                 }
 111         }
 112
 113         /**
 114          * Create a new Title from text, such as what one would find in a link. De-
 115          * codes any HTML entities in the text.
 116          *
 117          * @param $text String the link text; spaces, prefixes, and an
 118          *   initial ':' indicating the main namespace are accepted.
 119          * @param $defaultNamespace Int the namespace to use if none is speci-
 120          *   fied by a prefix.  If you want to force a specific namespace even if
 121          *   $text might begin with a namespace prefix, use makeTitle() or
 122          *   makeTitleSafe().
 123          * @return Title, or null on an error.
 124          */
 125         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 126                 if ( is_object( $text ) ) {
 127                         throw new MWException( 'Title::newFromText given an object' );
 128                 }
 129
 130                 /**
 131                  * Wiki pages often contain multiple links to the same page.
 132                  * Title normalization and parsing can become expensive on
 133                  * pages with many links, so we can save a little time by
 134                  * caching them.
 135                  *
 136                  * In theory these are value objects and won't get changed...
 137                  */
 138                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 139                         return Title::$titleCache[$text];
 140                 }
 141
 142                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 143                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 144
 145                 $t = new Title();
 146                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 147                 $t->mDefaultNamespace = $defaultNamespace;
 148
 149                 static $cachedcount = 0 ;
 150                 if ( $t->secureAndSplit() ) {
 151                         if ( $defaultNamespace == NS_MAIN ) {
 152                                 if ( $cachedcount >= self::CACHE_MAX ) {
 153                                         # Avoid memory leaks on mass operations...
 154                                         Title::$titleCache = array();
 155                                         $cachedcount = 0;
 156                                 }
 157                                 $cachedcount++;
 158                                 Title::$titleCache[$text] =& $t;
 159                         }
 160                         return $t;
 161                 } else {
 162                         $ret = null;
 163                         return $ret;
 164                 }
 165         }
 166
 167         /**
 168          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 169          *
 170          * Example of wrong and broken code:
 171          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 172          *
 173          * Example of right code:
 174          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 175          *
 176          * Create a new Title from URL-encoded text. Ensures that
 177          * the given title's length does not exceed the maximum.
 178          *
 179          * @param $url String the title, as might be taken from a URL
 180          * @return Title the new object, or NULL on an error
 181          */
 182         public static function newFromURL( $url ) {
 183                 global $wgLegalTitleChars;
 184                 $t = new Title();
 185
 186                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 187                 # but some URLs used it as a space replacement and they still come
 188                 # from some external search tools.
 189                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 190                         $url = str_replace( '+', ' ', $url );
 191                 }
 192
 193                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 194                 if ( $t->secureAndSplit() ) {
 195                         return $t;
 196                 } else {
 197                         return null;
 198                 }
 199         }
 200
 201         /**
 202          * Create a new Title from an article ID
 203          *
 204          * @param $id Int the page_id corresponding to the Title to create
 205          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 206          * @return Title the new object, or NULL on an error
 207          */
 208         public static function newFromID( $id, $flags = 0 ) {
 209                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 210                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 211                 if ( $row !== false ) {
 212                         $title = Title::newFromRow( $row );
 213                 } else {
 214                         $title = null;
 215                 }
 216                 return $title;
 217         }
 218
 219         /**
 220          * Make an array of titles from an array of IDs
 221          *
 222          * @param $ids Array of Int Array of IDs
 223          * @return Array of Titles
 224          */
 225         public static function newFromIDs( $ids ) {
 226                 if ( !count( $ids ) ) {
 227                         return array();
 228                 }
 229                 $dbr = wfGetDB( DB_SLAVE );
 230
 231                 $res = $dbr->select(
 232                         'page',
 233                         array(
 234                                 'page_namespace', 'page_title', 'page_id',
 235                                 'page_len', 'page_is_redirect', 'page_latest',
 236                         ),
 237                         array( 'page_id' => $ids ),
 238                         __METHOD__
 239                 );
 240
 241                 $titles = array();
 242                 foreach ( $res as $row ) {
 243                         $titles[] = Title::newFromRow( $row );
 244                 }
 245                 return $titles;
 246         }
 247
 248         /**
 249          * Make a Title object from a DB row
 250          *
 251          * @param $row Object database row (needs at least page_title,page_namespace)
 252          * @return Title corresponding Title
 253          */
 254         public static function newFromRow( $row ) {
 255                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 256                 $t->loadFromRow( $row );
 257                 return $t;
 258         }
 259
 260         /**
 261          * Load Title object fields from a DB row.
 262          * If false is given, the title will be treated as non-existing.
 263          *
 264          * @param $row Object|bool database row
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest; # FIXME: whene3ver page_latest is updated, also update page_content_model
 276                         if ( isset( $row->page_content_model ) )
 277                                 $this->mContentModel = $row->page_content_model;
 278                         else
 279                                 $this->mContentModel = null; # initialized lazily in getContentModel()
 280                 } else { // page not found
 281                         $this->mArticleID = 0;
 282                         $this->mLength = 0;
 283                         $this->mRedirect = false;
 284                         $this->mLatestID = 0;
 285                         $this->mContentModel = null; # initialized lazily in getContentModel()
 286                 }
 287         }
 288
 289         /**
 290          * Create a new Title from a namespace index and a DB key.
 291          * It's assumed that $ns and $title are *valid*, for instance when
 292          * they came directly from the database or a special page name.
 293          * For convenience, spaces are converted to underscores so that
 294          * eg user_text fields can be used directly.
 295          *
 296          * @param $ns Int the namespace of the article
 297          * @param $title String the unprefixed database key form
 298          * @param $fragment String the link fragment (after the "#")
 299          * @param $interwiki String the interwiki prefix
 300          * @return Title the new object
 301          */
 302         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 303                 $t = new Title();
 304                 $t->mInterwiki = $interwiki;
 305                 $t->mFragment = $fragment;
 306                 $t->mNamespace = $ns = intval( $ns );
 307                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 308                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 309                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 310                 $t->mTextform = str_replace( '_', ' ', $title );
 311                 $t->mContentModel = null; # initialized lazily in getContentModel()
 312                 return $t;
 313         }
 314
 315         /**
 316          * Create a new Title from a namespace index and a DB key.
 317          * The parameters will be checked for validity, which is a bit slower
 318          * than makeTitle() but safer for user-provided data.
 319          *
 320          * @param $ns Int the namespace of the article
 321          * @param $title String database key form
 322          * @param $fragment String the link fragment (after the "#")
 323          * @param $interwiki String interwiki prefix
 324          * @return Title the new object, or NULL on an error
 325          */
 326         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 327                 if ( !MWNamespace::exists( $ns ) ) {
 328                         return null;
 329                 }
 330
 331                 $t = new Title();
 332                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 333                 if ( $t->secureAndSplit() ) {
 334                         return $t;
 335                 } else {
 336                         return null;
 337                 }
 338         }
 339
 340         /**
 341          * Create a new Title for the Main Page
 342          *
 343          * @return Title the new object
 344          */
 345         public static function newMainPage() {
 346                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 347                 // Don't give fatal errors if the message is broken
 348                 if ( !$title ) {
 349                         $title = Title::newFromText( 'Main Page' );
 350                 }
 351                 return $title;
 352         }
 353
 354         /**
 355          * Extract a redirect destination from a string and return the
 356          * Title, or null if the text doesn't contain a valid redirect
 357          * This will only return the very next target, useful for
 358          * the redirect table and other checks that don't need full recursion
 359          *
 360          * @param $text String: Text with possible redirect
 361          * @return Title: The corresponding Title
 362          */
 363         public static function newFromRedirect( $text ) {
 364                 return self::newFromRedirectInternal( $text );
 365         }
 366
 367         /**
 368          * Extract a redirect destination from a string and return the
 369          * Title, or null if the text doesn't contain a valid redirect
 370          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 371          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 372          *
 373          * @param $text String Text with possible redirect
 374          * @return Title
 375          */
 376         public static function newFromRedirectRecurse( $text ) {
 377                 $titles = self::newFromRedirectArray( $text );
 378                 return $titles ? array_pop( $titles ) : null;
 379         }
 380
 381         /**
 382          * Extract a redirect destination from a string and return an
 383          * array of Titles, or null if the text doesn't contain a valid redirect
 384          * The last element in the array is the final destination after all redirects
 385          * have been resolved (up to $wgMaxRedirects times)
 386          *
 387          * @param $text String Text with possible redirect
 388          * @return Array of Titles, with the destination last
 389          */
 390         public static function newFromRedirectArray( $text ) {
 391                 global $wgMaxRedirects;
 392                 $title = self::newFromRedirectInternal( $text );
 393                 if ( is_null( $title ) ) {
 394                         return null;
 395                 }
 396                 // recursive check to follow double redirects
 397                 $recurse = $wgMaxRedirects;
 398                 $titles = array( $title );
 399                 while ( --$recurse > 0 ) {
 400                         if ( $title->isRedirect() ) {
 401                                 $page = WikiPage::factory( $title );
 402                                 $newtitle = $page->getRedirectTarget();
 403                         } else {
 404                                 break;
 405                         }
 406                         // Redirects to some special pages are not permitted
 407                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 408                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 409                                 $title = $newtitle;
 410                                 $titles[] = $newtitle;
 411                         } else {
 412                                 break;
 413                         }
 414                 }
 415                 return $titles;
 416         }
 417
 418         /**
 419          * Really extract the redirect destination
 420          * Do not call this function directly, use one of the newFromRedirect* functions above
 421          *
 422          * @param $text String Text with possible redirect
 423          * @return Title
 424          */
 425         protected static function newFromRedirectInternal( $text ) {
 426                 global $wgMaxRedirects;
 427                 if ( $wgMaxRedirects < 1 ) {
 428                         //redirects are disabled, so quit early
 429                         return null;
 430                 }
 431                 $redir = MagicWord::get( 'redirect' );
 432                 $text = trim( $text );
 433                 if ( $redir->matchStartAndRemove( $text ) ) {
 434                         // Extract the first link and see if it's usable
 435                         // Ensure that it really does come directly after #REDIRECT
 436                         // Some older redirects included a colon, so don't freak about that!
 437                         $m = array();
 438                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 439                                 // Strip preceding colon used to "escape" categories, etc.
 440                                 // and URL-decode links
 441                                 if ( strpos( $m[1], '%' ) !== false ) {
 442                                         // Match behavior of inline link parsing here;
 443                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 444                                 }
 445                                 $title = Title::newFromText( $m[1] );
 446                                 // If the title is a redirect to bad special pages or is invalid, return null
 447                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 448                                         return null;
 449                                 }
 450                                 return $title;
 451                         }
 452                 }
 453                 return null;
 454         }
 455
 456         /**
 457          * Get the prefixed DB key associated with an ID
 458          *
 459          * @param $id Int the page_id of the article
 460          * @return Title an object representing the article, or NULL if no such article was found
 461          */
 462         public static function nameOf( $id ) {
 463                 $dbr = wfGetDB( DB_SLAVE );
 464
 465                 $s = $dbr->selectRow(
 466                         'page',
 467                         array( 'page_namespace', 'page_title' ),
 468                         array( 'page_id' => $id ),
 469                         __METHOD__
 470                 );
 471                 if ( $s === false ) {
 472                         return null;
 473                 }
 474
 475                 $n = self::makeName( $s->page_namespace, $s->page_title );
 476                 return $n;
 477         }
 478
 479         /**
 480          * Get a regex character class describing the legal characters in a link
 481          *
 482          * @return String the list of characters, not delimited
 483          */
 484         public static function legalChars() {
 485                 global $wgLegalTitleChars;
 486                 return $wgLegalTitleChars;
 487         }
 488
 489         /**
 490          * Returns a simple regex that will match on characters and sequences invalid in titles.
 491          * Note that this doesn't pick up many things that could be wrong with titles, but that
 492          * replacing this regex with something valid will make many titles valid.
 493          *
 494          * @return String regex string
 495          */
 496         static function getTitleInvalidRegex() {
 497                 static $rxTc = false;
 498                 if ( !$rxTc ) {
 499                         # Matching titles will be held as illegal.
 500                         $rxTc = '/' .
 501                                 # Any character not allowed is forbidden...
 502                                 '[^' . self::legalChars() . ']' .
 503                                 # URL percent encoding sequences interfere with the ability
 504                                 # to round-trip titles -- you can't link to them consistently.
 505                                 '|%[0-9A-Fa-f]{2}' .
 506                                 # XML/HTML character references produce similar issues.
 507                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 508                                 '|&#[0-9]+;' .
 509                                 '|&#x[0-9A-Fa-f]+;' .
 510                                 '/S';
 511                 }
 512
 513                 return $rxTc;
 514         }
 515
 516         /**
 517          * Get a string representation of a title suitable for
 518          * including in a search index
 519          *
 520          * @param $ns Int a namespace index
 521          * @param $title String text-form main part
 522          * @return String a stripped-down title string ready for the search index
 523          */
 524         public static function indexTitle( $ns, $title ) {
 525                 global $wgContLang;
 526
 527                 $lc = SearchEngine::legalSearchChars() . '&#;';
 528                 $t = $wgContLang->normalizeForSearch( $title );
 529                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 530                 $t = $wgContLang->lc( $t );
 531
 532                 # Handle 's, s'
 533                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 534                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 535
 536                 $t = preg_replace( "/\\s+/", ' ', $t );
 537
 538                 if ( $ns == NS_FILE ) {
 539                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 540                 }
 541                 return trim( $t );
 542         }
 543
 544         /**
 545          * Make a prefixed DB key from a DB key and a namespace index
 546          *
 547          * @param $ns Int numerical representation of the namespace
 548          * @param $title String the DB key form the title
 549          * @param $fragment String The link fragment (after the "#")
 550          * @param $interwiki String The interwiki prefix
 551          * @return String the prefixed form of the title
 552          */
 553         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 554                 global $wgContLang;
 555
 556                 $namespace = $wgContLang->getNsText( $ns );
 557                 $name = $namespace == '' ? $title : "$namespace:$title";
 558                 if ( strval( $interwiki ) != '' ) {
 559                         $name = "$interwiki:$name";
 560                 }
 561                 if ( strval( $fragment ) != '' ) {
 562                         $name .= '#' . $fragment;
 563                 }
 564                 return $name;
 565         }
 566
 567         /**
 568          * Escape a text fragment, say from a link, for a URL
 569          *
 570          * @param $fragment string containing a URL or link fragment (after the "#")
 571          * @return String: escaped string
 572          */
 573         static function escapeFragmentForURL( $fragment ) {
 574                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 575                 # fragments appear not to work in IE (at least up to 7) or in at least
 576                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 577                 # to care if they aren't encoded.
 578                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 579         }
 580
 581         /**
 582          * Callback for usort() to do title sorts by (namespace, title)
 583          *
 584          * @param $a Title
 585          * @param $b Title
 586          *
 587          * @return Integer: result of string comparison, or namespace comparison
 588          */
 589         public static function compare( $a, $b ) {
 590                 if ( $a->getNamespace() == $b->getNamespace() ) {
 591                         return strcmp( $a->getText(), $b->getText() );
 592                 } else {
 593                         return $a->getNamespace() - $b->getNamespace();
 594                 }
 595         }
 596
 597         /**
 598          * Determine whether the object refers to a page within
 599          * this project.
 600          *
 601          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 602          */
 603         public function isLocal() {
 604                 if ( $this->mInterwiki != '' ) {
 605                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 606                 } else {
 607                         return true;
 608                 }
 609         }
 610
 611         /**
 612          * Is this Title interwiki?
 613          *
 614          * @return Bool
 615          */
 616         public function isExternal() {
 617                 return ( $this->mInterwiki != '' );
 618         }
 619
 620         /**
 621          * Get the interwiki prefix (or null string)
 622          *
 623          * @return String Interwiki prefix
 624          */
 625         public function getInterwiki() {
 626                 return $this->mInterwiki;
 627         }
 628
 629         /**
 630          * Determine whether the object refers to a page within
 631          * this project and is transcludable.
 632          *
 633          * @return Bool TRUE if this is transcludable
 634          */
 635         public function isTrans() {
 636                 if ( $this->mInterwiki == '' ) {
 637                         return false;
 638                 }
 639
 640                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 641         }
 642
 643         /**
 644          * Returns the DB name of the distant wiki which owns the object.
 645          *
 646          * @return String the DB name
 647          */
 648         public function getTransWikiID() {
 649                 if ( $this->mInterwiki == '' ) {
 650                         return false;
 651                 }
 652
 653                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 654         }
 655
 656         /**
 657          * Get the text form (spaces not underscores) of the main part
 658          *
 659          * @return String Main part of the title
 660          */
 661         public function getText() {
 662                 return $this->mTextform;
 663         }
 664
 665         /**
 666          * Get the URL-encoded form of the main part
 667          *
 668          * @return String Main part of the title, URL-encoded
 669          */
 670         public function getPartialURL() {
 671                 return $this->mUrlform;
 672         }
 673
 674         /**
 675          * Get the main part with underscores
 676          *
 677          * @return String: Main part of the title, with underscores
 678          */
 679         public function getDBkey() {
 680                 return $this->mDbkeyform;
 681         }
 682
 683         /**
 684          * Get the DB key with the initial letter case as specified by the user
 685          *
 686          * @return String DB key
 687          */
 688         function getUserCaseDBKey() {
 689                 return $this->mUserCaseDBKey;
 690         }
 691
 692         /**
 693          * Get the namespace index, i.e. one of the NS_xxxx constants.
 694          *
 695          * @return Integer: Namespace index
 696          */
 697         public function getNamespace() {
 698                 return $this->mNamespace;
 699         }
 700
 701         /**
 702          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 703          *
 704          * @return Integer: Content model id
 705          */
 706         public function getContentModel() {
 707                 if ( empty( $this->mContentModel ) ) {
 708                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 709                 }
 710
 711                 assert( !empty( $this->mContentModel ) );
 712                 return $this->mContentModel;
 713         }
 714
 715         /**
 716          * Conveniance method for checking a title's content model name
 717          *
 718          * @param int $id
 719          * @return true if $this->getContentModel() == $id
 720          */
 721         public function hasContentModel( $id ) {
 722                 return $this->getContentModel() == $id;
 723         }
 724
 725         /**
 726          * Get the namespace text
 727          *
 728          * @return String: Namespace text
 729          */
 730         public function getNsText() {
 731                 global $wgContLang;
 732
 733                 if ( $this->mInterwiki != '' ) {
 734                         // This probably shouldn't even happen. ohh man, oh yuck.
 735                         // But for interwiki transclusion it sometimes does.
 736                         // Shit. Shit shit shit.
 737                         //
 738                         // Use the canonical namespaces if possible to try to
 739                         // resolve a foreign namespace.
 740                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 741                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 742                         }
 743                 }
 744
 745                 if ( $wgContLang->needsGenderDistinction() &&
 746                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 747                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 748                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 749                 }
 750
 751                 return $wgContLang->getNsText( $this->mNamespace );
 752         }
 753
 754         /**
 755          * Get the namespace text of the subject (rather than talk) page
 756          *
 757          * @return String Namespace text
 758          */
 759         public function getSubjectNsText() {
 760                 global $wgContLang;
 761                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 762         }
 763
 764         /**
 765          * Get the namespace text of the talk page
 766          *
 767          * @return String Namespace text
 768          */
 769         public function getTalkNsText() {
 770                 global $wgContLang;
 771                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 772         }
 773
 774         /**
 775          * Could this title have a corresponding talk page?
 776          *
 777          * @return Bool TRUE or FALSE
 778          */
 779         public function canTalk() {
 780                 return( MWNamespace::canTalk( $this->mNamespace ) );
 781         }
 782
 783         /**
 784          * Is this in a namespace that allows actual pages?
 785          *
 786          * @return Bool
 787          * @internal note -- uses hardcoded namespace index instead of constants
 788          */
 789         public function canExist() {
 790                 return $this->mNamespace >= NS_MAIN;
 791         }
 792
 793         /**
 794          * Can this title be added to a user's watchlist?
 795          *
 796          * @return Bool TRUE or FALSE
 797          */
 798         public function isWatchable() {
 799                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 800         }
 801
 802         /**
 803          * Returns true if this is a special page.
 804          *
 805          * @return boolean
 806          */
 807         public function isSpecialPage() {
 808                 return $this->getNamespace() == NS_SPECIAL;
 809         }
 810
 811         /**
 812          * Returns true if this title resolves to the named special page
 813          *
 814          * @param $name String The special page name
 815          * @return boolean
 816          */
 817         public function isSpecial( $name ) {
 818                 if ( $this->isSpecialPage() ) {
 819                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 820                         if ( $name == $thisName ) {
 821                                 return true;
 822                         }
 823                 }
 824                 return false;
 825         }
 826
 827         /**
 828          * If the Title refers to a special page alias which is not the local default, resolve
 829          * the alias, and localise the name as necessary.  Otherwise, return $this
 830          *
 831          * @return Title
 832          */
 833         public function fixSpecialName() {
 834                 if ( $this->isSpecialPage() ) {
 835                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 836                         if ( $canonicalName ) {
 837                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 838                                 if ( $localName != $this->mDbkeyform ) {
 839                                         return Title::makeTitle( NS_SPECIAL, $localName );
 840                                 }
 841                         }
 842                 }
 843                 return $this;
 844         }
 845
 846         /**
 847          * Returns true if the title is inside the specified namespace.
 848          *
 849          * Please make use of this instead of comparing to getNamespace()
 850          * This function is much more resistant to changes we may make
 851          * to namespaces than code that makes direct comparisons.
 852          * @param $ns int The namespace
 853          * @return bool
 854          * @since 1.19
 855          */
 856         public function inNamespace( $ns ) {
 857                 return MWNamespace::equals( $this->getNamespace(), $ns );
 858         }
 859
 860         /**
 861          * Returns true if the title is inside one of the specified namespaces.
 862          *
 863          * @param ...$namespaces The namespaces to check for
 864          * @return bool
 865          * @since 1.19
 866          */
 867         public function inNamespaces( /* ... */ ) {
 868                 $namespaces = func_get_args();
 869                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 870                         $namespaces = $namespaces[0];
 871                 }
 872
 873                 foreach ( $namespaces as $ns ) {
 874                         if ( $this->inNamespace( $ns ) ) {
 875                                 return true;
 876                         }
 877                 }
 878
 879                 return false;
 880         }
 881
 882         /**
 883          * Returns true if the title has the same subject namespace as the
 884          * namespace specified.
 885          * For example this method will take NS_USER and return true if namespace
 886          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 887          * as their subject namespace.
 888          *
 889          * This is MUCH simpler than individually testing for equivilance
 890          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 891          * @since 1.19
 892          * @return bool
 893          */
 894         public function hasSubjectNamespace( $ns ) {
 895                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 896         }
 897
 898         /**
 899          * Is this Title in a namespace which contains content?
 900          * In other words, is this a content page, for the purposes of calculating
 901          * statistics, etc?
 902          *
 903          * @return Boolean
 904          */
 905         public function isContentPage() {
 906                 return MWNamespace::isContent( $this->getNamespace() );
 907         }
 908
 909         /**
 910          * Would anybody with sufficient privileges be able to move this page?
 911          * Some pages just aren't movable.
 912          *
 913          * @return Bool TRUE or FALSE
 914          */
 915         public function isMovable() {
 916                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 917                         // Interwiki title or immovable namespace. Hooks don't get to override here
 918                         return false;
 919                 }
 920
 921                 $result = true;
 922                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 923                 return $result;
 924         }
 925
 926         /**
 927          * Is this the mainpage?
 928          * @note Title::newFromText seams to be sufficiently optimized by the title
 929          * cache that we don't need to over-optimize by doing direct comparisons and
 930          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 931          * ends up reporting something differently than $title->isMainPage();
 932          *
 933          * @since 1.18
 934          * @return Bool
 935          */
 936         public function isMainPage() {
 937                 return $this->equals( Title::newMainPage() );
 938         }
 939
 940         /**
 941          * Is this a subpage?
 942          *
 943          * @return Bool
 944          */
 945         public function isSubpage() {
 946                 return MWNamespace::hasSubpages( $this->mNamespace )
 947                         ? strpos( $this->getText(), '/' ) !== false
 948                         : false;
 949         }
 950
 951         /**
 952          * Is this a conversion table for the LanguageConverter?
 953          *
 954          * @return Bool
 955          */
 956         public function isConversionTable() {
 957                 return $this->getNamespace() == NS_MEDIAWIKI &&
 958                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 959         }
 960
 961         /**
 962          * Does that page contain wikitext, or it is JS, CSS or whatever?
 963          *
 964          * @return Bool
 965          */
 966         public function isWikitextPage() {
 967                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 968         }
 969
 970         /**
 971          * Could this page contain custom CSS or JavaScript for the global UI.
 972          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 973          * or CONTENT_MODEL_JAVASCRIPT.
 974          *
 975          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 976          *
 977          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 978          *
 979          * @return Bool
 980          */
 981         public function isCssOrJsPage() {
 982                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 983                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 984                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 985
 986                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 987                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 988
 989                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 990
 991                 return $isCssOrJsPage;
 992         }
 993
 994         /**
 995          * Is this a .css or .js subpage of a user page?
 996          * @return Bool
 997          */
 998         public function isCssJsSubpage() {
 999                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1000                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1001                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1002         }
1003
1004         /**
1005          * Trim down a .css or .js subpage title to get the corresponding skin name
1006          *
1007          * @return string containing skin name from .css or .js subpage title
1008          */
1009         public function getSkinFromCssJsSubpage() {
1010                 $subpage = explode( '/', $this->mTextform );
1011                 $subpage = $subpage[ count( $subpage ) - 1 ];
1012                 $lastdot = strrpos( $subpage, '.' );
1013                 if ( $lastdot === false )
1014                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1015                 return substr( $subpage, 0, $lastdot );
1016         }
1017
1018         /**
1019          * Is this a .css subpage of a user page?
1020          *
1021          * @return Bool
1022          */
1023         public function isCssSubpage() {
1024                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1025                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1026         }
1027
1028         /**
1029          * Is this a .js subpage of a user page?
1030          *
1031          * @return Bool
1032          */
1033         public function isJsSubpage() {
1034                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1035                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1036         }
1037
1038         /**
1039          * Is this a talk page of some sort?
1040          *
1041          * @return Bool
1042          */
1043         public function isTalkPage() {
1044                 return MWNamespace::isTalk( $this->getNamespace() );
1045         }
1046
1047         /**
1048          * Get a Title object associated with the talk page of this article
1049          *
1050          * @return Title the object for the talk page
1051          */
1052         public function getTalkPage() {
1053                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1054         }
1055
1056         /**
1057          * Get a title object associated with the subject page of this
1058          * talk page
1059          *
1060          * @return Title the object for the subject page
1061          */
1062         public function getSubjectPage() {
1063                 // Is this the same title?
1064                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1065                 if ( $this->getNamespace() == $subjectNS ) {
1066                         return $this;
1067                 }
1068                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1069         }
1070
1071         /**
1072          * Get the default namespace index, for when there is no namespace
1073          *
1074          * @return Int Default namespace index
1075          */
1076         public function getDefaultNamespace() {
1077                 return $this->mDefaultNamespace;
1078         }
1079
1080         /**
1081          * Get title for search index
1082          *
1083          * @return String a stripped-down title string ready for the
1084          *  search index
1085          */
1086         public function getIndexTitle() {
1087                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1088         }
1089
1090         /**
1091          * Get the Title fragment (i.e.\ the bit after the #) in text form
1092          *
1093          * @return String Title fragment
1094          */
1095         public function getFragment() {
1096                 return $this->mFragment;
1097         }
1098
1099         /**
1100          * Get the fragment in URL form, including the "#" character if there is one
1101          * @return String Fragment in URL form
1102          */
1103         public function getFragmentForURL() {
1104                 if ( $this->mFragment == '' ) {
1105                         return '';
1106                 } else {
1107                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1108                 }
1109         }
1110
1111         /**
1112          * Set the fragment for this title. Removes the first character from the
1113          * specified fragment before setting, so it assumes you're passing it with
1114          * an initial "#".
1115          *
1116          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1117          * Still in active use privately.
1118          *
1119          * @param $fragment String text
1120          */
1121         public function setFragment( $fragment ) {
1122                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1123         }
1124
1125         /**
1126          * Prefix some arbitrary text with the namespace or interwiki prefix
1127          * of this object
1128          *
1129          * @param $name String the text
1130          * @return String the prefixed text
1131          * @private
1132          */
1133         private function prefix( $name ) {
1134                 $p = '';
1135                 if ( $this->mInterwiki != '' ) {
1136                         $p = $this->mInterwiki . ':';
1137                 }
1138
1139                 if ( 0 != $this->mNamespace ) {
1140                         $p .= $this->getNsText() . ':';
1141                 }
1142                 return $p . $name;
1143         }
1144
1145         /**
1146          * Get the prefixed database key form
1147          *
1148          * @return String the prefixed title, with underscores and
1149          *  any interwiki and namespace prefixes
1150          */
1151         public function getPrefixedDBkey() {
1152                 $s = $this->prefix( $this->mDbkeyform );
1153                 $s = str_replace( ' ', '_', $s );
1154                 return $s;
1155         }
1156
1157         /**
1158          * Get the prefixed title with spaces.
1159          * This is the form usually used for display
1160          *
1161          * @return String the prefixed title, with spaces
1162          */
1163         public function getPrefixedText() {
1164                 // @todo FIXME: Bad usage of empty() ?
1165                 if ( empty( $this->mPrefixedText ) ) {
1166                         $s = $this->prefix( $this->mTextform );
1167                         $s = str_replace( '_', ' ', $s );
1168                         $this->mPrefixedText = $s;
1169                 }
1170                 return $this->mPrefixedText;
1171         }
1172
1173         /**
1174          * Return a string representation of this title
1175          *
1176          * @return String representation of this title
1177          */
1178         public function __toString() {
1179                 return $this->getPrefixedText();
1180         }
1181
1182         /**
1183          * Get the prefixed title with spaces, plus any fragment
1184          * (part beginning with '#')
1185          *
1186          * @return String the prefixed title, with spaces and the fragment, including '#'
1187          */
1188         public function getFullText() {
1189                 $text = $this->getPrefixedText();
1190                 if ( $this->mFragment != '' ) {
1191                         $text .= '#' . $this->mFragment;
1192                 }
1193                 return $text;
1194         }
1195
1196         /**
1197          * Get the base page name, i.e. the leftmost part before any slashes
1198          *
1199          * @return String Base name
1200          */
1201         public function getBaseText() {
1202                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1203                         return $this->getText();
1204                 }
1205
1206                 $parts = explode( '/', $this->getText() );
1207                 # Don't discard the real title if there's no subpage involved
1208                 if ( count( $parts ) > 1 ) {
1209                         unset( $parts[count( $parts ) - 1] );
1210                 }
1211                 return implode( '/', $parts );
1212         }
1213
1214         /**
1215          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1216          *
1217          * @return String Subpage name
1218          */
1219         public function getSubpageText() {
1220                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1221                         return( $this->mTextform );
1222                 }
1223                 $parts = explode( '/', $this->mTextform );
1224                 return( $parts[count( $parts ) - 1] );
1225         }
1226
1227         /**
1228          * Get the HTML-escaped displayable text form.
1229          * Used for the title field in <a> tags.
1230          *
1231          * @return String the text, including any prefixes
1232          */
1233         public function getEscapedText() {
1234                 wfDeprecated( __METHOD__, '1.19' );
1235                 return htmlspecialchars( $this->getPrefixedText() );
1236         }
1237
1238         /**
1239          * Get a URL-encoded form of the subpage text
1240          *
1241          * @return String URL-encoded subpage name
1242          */
1243         public function getSubpageUrlForm() {
1244                 $text = $this->getSubpageText();
1245                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1246                 return( $text );
1247         }
1248
1249         /**
1250          * Get a URL-encoded title (not an actual URL) including interwiki
1251          *
1252          * @return String the URL-encoded form
1253          */
1254         public function getPrefixedURL() {
1255                 $s = $this->prefix( $this->mDbkeyform );
1256                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1257                 return $s;
1258         }
1259
1260         /**
1261          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1262          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1263          * second argument named variant. This was deprecated in favor
1264          * of passing an array of option with a "variant" key
1265          * Once $query2 is removed for good, this helper can be dropped
1266          * andthe wfArrayToCGI moved to getLocalURL();
1267          *
1268          * @since 1.19 (r105919)
1269          * @return String
1270          */
1271         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1272                 if( $query2 !== false ) {
1273                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1274                 }
1275                 if ( is_array( $query ) ) {
1276                         $query = wfArrayToCGI( $query );
1277                 }
1278                 if ( $query2 ) {
1279                         if ( is_string( $query2 ) ) {
1280                                 // $query2 is a string, we will consider this to be
1281                                 // a deprecated $variant argument and add it to the query
1282                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1283                         } else {
1284                                 $query2 = wfArrayToCGI( $query2 );
1285                         }
1286                         // If we have $query content add a & to it first
1287                         if ( $query ) {
1288                                 $query .= '&';
1289                         }
1290                         // Now append the queries together
1291                         $query .= $query2;
1292                 }
1293                 return $query;
1294         }
1295
1296         /**
1297          * Get a real URL referring to this title, with interwiki link and
1298          * fragment
1299          *
1300          * See getLocalURL for the arguments.
1301          *
1302          * @see self::getLocalURL
1303          * @return String the URL
1304          */
1305         public function getFullURL( $query = '', $query2 = false ) {
1306                 $query = self::fixUrlQueryArgs( $query, $query2 );
1307
1308                 # Hand off all the decisions on urls to getLocalURL
1309                 $url = $this->getLocalURL( $query );
1310
1311                 # Expand the url to make it a full url. Note that getLocalURL has the
1312                 # potential to output full urls for a variety of reasons, so we use
1313                 # wfExpandUrl instead of simply prepending $wgServer
1314                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1315
1316                 # Finally, add the fragment.
1317                 $url .= $this->getFragmentForURL();
1318
1319                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1320                 return $url;
1321         }
1322
1323         /**
1324          * Get a URL with no fragment or server name.  If this page is generated
1325          * with action=render, $wgServer is prepended.
1326          *
1327
1328          * @param $query string|array an optional query string,
1329          *   not used for interwiki     links. Can be specified as an associative array as well,
1330          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1331          *   Some query patterns will trigger various shorturl path replacements.
1332          * @param $query2 Mixed: An optional secondary query array. This one MUST
1333          *   be an array. If a string is passed it will be interpreted as a deprecated
1334          *   variant argument and urlencoded into a variant= argument.
1335          *   This second query argument will be added to the $query
1336          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1337          *   pair in the first parameter array instead.
1338          *
1339          * @return String the URL
1340          */
1341         public function getLocalURL( $query = '', $query2 = false ) {
1342                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1343
1344                 $query = self::fixUrlQueryArgs( $query, $query2 );
1345
1346                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1347                 if ( $interwiki ) {
1348                         $namespace = $this->getNsText();
1349                         if ( $namespace != '' ) {
1350                                 # Can this actually happen? Interwikis shouldn't be parsed.
1351                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1352                                 $namespace .= ':';
1353                         }
1354                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1355                         $url = wfAppendQuery( $url, $query );
1356                 } else {
1357                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1358                         if ( $query == '' ) {
1359                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1360                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1361                         } else {
1362                                 global $wgVariantArticlePath, $wgActionPaths;
1363                                 $url = false;
1364                                 $matches = array();
1365
1366                                 if ( !empty( $wgActionPaths ) &&
1367                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1368                                 {
1369                                         $action = urldecode( $matches[2] );
1370                                         if ( isset( $wgActionPaths[$action] ) ) {
1371                                                 $query = $matches[1];
1372                                                 if ( isset( $matches[4] ) ) {
1373                                                         $query .= $matches[4];
1374                                                 }
1375                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1376                                                 if ( $query != '' ) {
1377                                                         $url = wfAppendQuery( $url, $query );
1378                                                 }
1379                                         }
1380                                 }
1381
1382                                 if ( $url === false &&
1383                                         $wgVariantArticlePath &&
1384                                         $this->getPageLanguage()->hasVariants() &&
1385                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1386                                 {
1387                                         $variant = urldecode( $matches[1] );
1388                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1389                                                 // Only do the variant replacement if the given variant is a valid
1390                                                 // variant for the page's language.
1391                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1392                                                 $url = str_replace( '$1', $dbkey, $url );
1393                                         }
1394                                 }
1395
1396                                 if ( $url === false ) {
1397                                         if ( $query == '-' ) {
1398                                                 $query = '';
1399                                         }
1400                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1401                                 }
1402                         }
1403
1404                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1405
1406                         // @todo FIXME: This causes breakage in various places when we
1407                         // actually expected a local URL and end up with dupe prefixes.
1408                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1409                                 $url = $wgServer . $url;
1410                         }
1411                 }
1412                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1413                 return $url;
1414         }
1415
1416         /**
1417          * Get a URL that's the simplest URL that will be valid to link, locally,
1418          * to the current Title.  It includes the fragment, but does not include
1419          * the server unless action=render is used (or the link is external).  If
1420          * there's a fragment but the prefixed text is empty, we just return a link
1421          * to the fragment.
1422          *
1423          * The result obviously should not be URL-escaped, but does need to be
1424          * HTML-escaped if it's being output in HTML.
1425          *
1426          * See getLocalURL for the arguments.
1427          *
1428          * @see self::getLocalURL
1429          * @return String the URL
1430          */
1431         public function getLinkURL( $query = '', $query2 = false ) {
1432                 wfProfileIn( __METHOD__ );
1433                 if ( $this->isExternal() ) {
1434                         $ret = $this->getFullURL( $query, $query2 );
1435                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1436                         $ret = $this->getFragmentForURL();
1437                 } else {
1438                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1439                 }
1440                 wfProfileOut( __METHOD__ );
1441                 return $ret;
1442         }
1443
1444         /**
1445          * Get an HTML-escaped version of the URL form, suitable for
1446          * using in a link, without a server name or fragment
1447          *
1448          * See getLocalURL for the arguments.
1449          *
1450          * @see self::getLocalURL
1451          * @return String the URL
1452          */
1453         public function escapeLocalURL( $query = '', $query2 = false ) {
1454                 wfDeprecated( __METHOD__, '1.19' );
1455                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1456         }
1457
1458         /**
1459          * Get an HTML-escaped version of the URL form, suitable for
1460          * using in a link, including the server name and fragment
1461          *
1462          * See getLocalURL for the arguments.
1463          *
1464          * @see self::getLocalURL
1465          * @return String the URL
1466          */
1467         public function escapeFullURL( $query = '', $query2 = false ) {
1468                 wfDeprecated( __METHOD__, '1.19' );
1469                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1470         }
1471
1472         /**
1473          * Get the URL form for an internal link.
1474          * - Used in various Squid-related code, in case we have a different
1475          * internal hostname for the server from the exposed one.
1476          *
1477          * This uses $wgInternalServer to qualify the path, or $wgServer
1478          * if $wgInternalServer is not set. If the server variable used is
1479          * protocol-relative, the URL will be expanded to http://
1480          *
1481          * See getLocalURL for the arguments.
1482          *
1483          * @see self::getLocalURL
1484          * @return String the URL
1485          */
1486         public function getInternalURL( $query = '', $query2 = false ) {
1487                 global $wgInternalServer, $wgServer;
1488                 $query = self::fixUrlQueryArgs( $query, $query2 );
1489                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1490                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1491                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1492                 return $url;
1493         }
1494
1495         /**
1496          * Get the URL for a canonical link, for use in things like IRC and
1497          * e-mail notifications. Uses $wgCanonicalServer and the
1498          * GetCanonicalURL hook.
1499          *
1500          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1501          *
1502          * See getLocalURL for the arguments.
1503          *
1504          * @see self::getLocalURL
1505          * @return string The URL
1506          * @since 1.18
1507          */
1508         public function getCanonicalURL( $query = '', $query2 = false ) {
1509                 $query = self::fixUrlQueryArgs( $query, $query2 );
1510                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1511                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1512                 return $url;
1513         }
1514
1515         /**
1516          * HTML-escaped version of getCanonicalURL()
1517          *
1518          * See getLocalURL for the arguments.
1519          *
1520          * @see self::getLocalURL
1521          * @since 1.18
1522          * @return string
1523          */
1524         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1525                 wfDeprecated( __METHOD__, '1.19' );
1526                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1527         }
1528
1529         /**
1530          * Get the edit URL for this Title
1531          *
1532          * @return String the URL, or a null string if this is an
1533          *  interwiki link
1534          */
1535         public function getEditURL() {
1536                 if ( $this->mInterwiki != '' ) {
1537                         return '';
1538                 }
1539                 $s = $this->getLocalURL( 'action=edit' );
1540
1541                 return $s;
1542         }
1543
1544         /**
1545          * Is $wgUser watching this page?
1546          *
1547          * @return Bool
1548          */
1549         public function userIsWatching() {
1550                 global $wgUser;
1551
1552                 if ( is_null( $this->mWatched ) ) {
1553                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1554                                 $this->mWatched = false;
1555                         } else {
1556                                 $this->mWatched = $wgUser->isWatched( $this );
1557                         }
1558                 }
1559                 return $this->mWatched;
1560         }
1561
1562         /**
1563          * Can $wgUser read this page?
1564          *
1565          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1566          * @return Bool
1567          * @todo fold these checks into userCan()
1568          */
1569         public function userCanRead() {
1570                 wfDeprecated( __METHOD__, '1.19' );
1571                 return $this->userCan( 'read' );
1572         }
1573
1574         /**
1575          * Can $user perform $action on this page?
1576          * This skips potentially expensive cascading permission checks
1577          * as well as avoids expensive error formatting
1578          *
1579          * Suitable for use for nonessential UI controls in common cases, but
1580          * _not_ for functional access control.
1581          *
1582          * May provide false positives, but should never provide a false negative.
1583          *
1584          * @param $action String action that permission needs to be checked for
1585          * @param $user User to check (since 1.19); $wgUser will be used if not
1586          *              provided.
1587          * @return Bool
1588          */
1589         public function quickUserCan( $action, $user = null ) {
1590                 return $this->userCan( $action, $user, false );
1591         }
1592
1593         /**
1594          * Can $user perform $action on this page?
1595          *
1596          * @param $action String action that permission needs to be checked for
1597          * @param $user User to check (since 1.19); $wgUser will be used if not
1598          *   provided.
1599          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1600          *   unnecessary queries.
1601          * @return Bool
1602          */
1603         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1604                 if ( !$user instanceof User ) {
1605                         global $wgUser;
1606                         $user = $wgUser;
1607                 }
1608                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1609         }
1610
1611         /**
1612          * Can $user perform $action on this page?
1613          *
1614          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1615          *
1616          * @param $action String action that permission needs to be checked for
1617          * @param $user User to check
1618          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1619          *   queries by skipping checks for cascading protections and user blocks.
1620          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1621          *   whose corresponding errors may be ignored.
1622          * @return Array of arguments to wfMsg to explain permissions problems.
1623          */
1624         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1625                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1626
1627                 // Remove the errors being ignored.
1628                 foreach ( $errors as $index => $error ) {
1629                         $error_key = is_array( $error ) ? $error[0] : $error;
1630
1631                         if ( in_array( $error_key, $ignoreErrors ) ) {
1632                                 unset( $errors[$index] );
1633                         }
1634                 }
1635
1636                 return $errors;
1637         }
1638
1639         /**
1640          * Permissions checks that fail most often, and which are easiest to test.
1641          *
1642          * @param $action String the action to check
1643          * @param $user User user to check
1644          * @param $errors Array list of current errors
1645          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1646          * @param $short Boolean short circuit on first error
1647          *
1648          * @return Array list of errors
1649          */
1650         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1651                 if ( $action == 'create' ) {
1652                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1653                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1654                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1655                         }
1656                 } elseif ( $action == 'move' ) {
1657                         if ( !$user->isAllowed( 'move-rootuserpages' )
1658                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1659                                 // Show user page-specific message only if the user can move other pages
1660                                 $errors[] = array( 'cant-move-user-page' );
1661                         }
1662
1663                         // Check if user is allowed to move files if it's a file
1664                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1665                                 $errors[] = array( 'movenotallowedfile' );
1666                         }
1667
1668                         if ( !$user->isAllowed( 'move' ) ) {
1669                                 // User can't move anything
1670                                 global $wgGroupPermissions;
1671                                 $userCanMove = false;
1672                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1673                                         $userCanMove = $wgGroupPermissions['user']['move'];
1674                                 }
1675                                 $autoconfirmedCanMove = false;
1676                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1677                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1678                                 }
1679                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1680                                         // custom message if logged-in users without any special rights can move
1681                                         $errors[] = array( 'movenologintext' );
1682                                 } else {
1683                                         $errors[] = array( 'movenotallowed' );
1684                                 }
1685                         }
1686                 } elseif ( $action == 'move-target' ) {
1687                         if ( !$user->isAllowed( 'move' ) ) {
1688                                 // User can't move anything
1689                                 $errors[] = array( 'movenotallowed' );
1690                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1691                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1692                                 // Show user page-specific message only if the user can move other pages
1693                                 $errors[] = array( 'cant-move-to-user-page' );
1694                         }
1695                 } elseif ( !$user->isAllowed( $action ) ) {
1696                         $errors[] = $this->missingPermissionError( $action, $short );
1697                 }
1698
1699                 return $errors;
1700         }
1701
1702         /**
1703          * Add the resulting error code to the errors array
1704          *
1705          * @param $errors Array list of current errors
1706          * @param $result Mixed result of errors
1707          *
1708          * @return Array list of errors
1709          */
1710         private function resultToError( $errors, $result ) {
1711                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1712                         // A single array representing an error
1713                         $errors[] = $result;
1714                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1715                         // A nested array representing multiple errors
1716                         $errors = array_merge( $errors, $result );
1717                 } elseif ( $result !== '' && is_string( $result ) ) {
1718                         // A string representing a message-id
1719                         $errors[] = array( $result );
1720                 } elseif ( $result === false ) {
1721                         // a generic "We don't want them to do that"
1722                         $errors[] = array( 'badaccess-group0' );
1723                 }
1724                 return $errors;
1725         }
1726
1727         /**
1728          * Check various permission hooks
1729          *
1730          * @param $action String the action to check
1731          * @param $user User user to check
1732          * @param $errors Array list of current errors
1733          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1734          * @param $short Boolean short circuit on first error
1735          *
1736          * @return Array list of errors
1737          */
1738         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1739                 // Use getUserPermissionsErrors instead
1740                 $result = '';
1741                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1742                         return $result ? array() : array( array( 'badaccess-group0' ) );
1743                 }
1744                 // Check getUserPermissionsErrors hook
1745                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1746                         $errors = $this->resultToError( $errors, $result );
1747                 }
1748                 // Check getUserPermissionsErrorsExpensive hook
1749                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1750                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1751                         $errors = $this->resultToError( $errors, $result );
1752                 }
1753
1754                 return $errors;
1755         }
1756
1757         /**
1758          * Check permissions on special pages & namespaces
1759          *
1760          * @param $action String the action to check
1761          * @param $user User user to check
1762          * @param $errors Array list of current errors
1763          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1764          * @param $short Boolean short circuit on first error
1765          *
1766          * @return Array list of errors
1767          */
1768         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1769                 # Only 'createaccount' and 'execute' can be performed on
1770                 # special pages, which don't actually exist in the DB.
1771                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1772                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1773                         $errors[] = array( 'ns-specialprotected' );
1774                 }
1775
1776                 # Check $wgNamespaceProtection for restricted namespaces
1777                 if ( $this->isNamespaceProtected( $user ) ) {
1778                         $ns = $this->mNamespace == NS_MAIN ?
1779                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1780                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1781                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1782                 }
1783
1784                 return $errors;
1785         }
1786
1787         /**
1788          * Check CSS/JS sub-page permissions
1789          *
1790          * @param $action String the action to check
1791          * @param $user User user to check
1792          * @param $errors Array list of current errors
1793          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1794          * @param $short Boolean short circuit on first error
1795          *
1796          * @return Array list of errors
1797          */
1798         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1799                 # Protect css/js subpages of user pages
1800                 # XXX: this might be better using restrictions
1801                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1802                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1803                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1804                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1805                                 $errors[] = array( 'customcssprotected' );
1806                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1807                                 $errors[] = array( 'customjsprotected' );
1808                         }
1809                 }
1810
1811                 return $errors;
1812         }
1813
1814         /**
1815          * Check against page_restrictions table requirements on this
1816          * page. The user must possess all required rights for this
1817          * action.
1818          *
1819          * @param $action String the action to check
1820          * @param $user User user to check
1821          * @param $errors Array list of current errors
1822          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1823          * @param $short Boolean short circuit on first error
1824          *
1825          * @return Array list of errors
1826          */
1827         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1828                 foreach ( $this->getRestrictions( $action ) as $right ) {
1829                         // Backwards compatibility, rewrite sysop -> protect
1830                         if ( $right == 'sysop' ) {
1831                                 $right = 'protect';
1832                         }
1833                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1834                                 // Users with 'editprotected' permission can edit protected pages
1835                                 // without cascading option turned on.
1836                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1837                                         || $this->mCascadeRestriction )
1838                                 {
1839                                         $errors[] = array( 'protectedpagetext', $right );
1840                                 }
1841                         }
1842                 }
1843
1844                 return $errors;
1845         }
1846
1847         /**
1848          * Check restrictions on cascading pages.
1849          *
1850          * @param $action String the action to check
1851          * @param $user User to check
1852          * @param $errors Array list of current errors
1853          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1854          * @param $short Boolean short circuit on first error
1855          *
1856          * @return Array list of errors
1857          */
1858         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1859                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1860                         # We /could/ use the protection level on the source page, but it's
1861                         # fairly ugly as we have to establish a precedence hierarchy for pages
1862                         # included by multiple cascade-protected pages. So just restrict
1863                         # it to people with 'protect' permission, as they could remove the
1864                         # protection anyway.
1865                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1866                         # Cascading protection depends on more than this page...
1867                         # Several cascading protected pages may include this page...
1868                         # Check each cascading level
1869                         # This is only for protection restrictions, not for all actions
1870                         if ( isset( $restrictions[$action] ) ) {
1871                                 foreach ( $restrictions[$action] as $right ) {
1872                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1873                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1874                                                 $pages = '';
1875                                                 foreach ( $cascadingSources as $page )
1876                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1877                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1878                                         }
1879                                 }
1880                         }
1881                 }
1882
1883                 return $errors;
1884         }
1885
1886         /**
1887          * Check action permissions not already checked in checkQuickPermissions
1888          *
1889          * @param $action String the action to check
1890          * @param $user User to check
1891          * @param $errors Array list of current errors
1892          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1893          * @param $short Boolean short circuit on first error
1894          *
1895          * @return Array list of errors
1896          */
1897         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1898                 global $wgDeleteRevisionsLimit, $wgLang;
1899
1900                 if ( $action == 'protect' ) {
1901                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1902                                 // If they can't edit, they shouldn't protect.
1903                                 $errors[] = array( 'protect-cantedit' );
1904                         }
1905                 } elseif ( $action == 'create' ) {
1906                         $title_protection = $this->getTitleProtection();
1907                         if( $title_protection ) {
1908                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1909                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1910                                 }
1911                                 if( $title_protection['pt_create_perm'] == '' ||
1912                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1913                                 {
1914                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1915                                 }
1916                         }
1917                 } elseif ( $action == 'move' ) {
1918                         // Check for immobile pages
1919                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1920                                 // Specific message for this case
1921                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1922                         } elseif ( !$this->isMovable() ) {
1923                                 // Less specific message for rarer cases
1924                                 $errors[] = array( 'immobile-source-page' );
1925                         }
1926                 } elseif ( $action == 'move-target' ) {
1927                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1928                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1929                         } elseif ( !$this->isMovable() ) {
1930                                 $errors[] = array( 'immobile-target-page' );
1931                         }
1932                 } elseif ( $action == 'delete' ) {
1933                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1934                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1935                         {
1936                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1937                         }
1938                 }
1939                 return $errors;
1940         }
1941
1942         /**
1943          * Check that the user isn't blocked from editting.
1944          *
1945          * @param $action String the action to check
1946          * @param $user User to check
1947          * @param $errors Array list of current errors
1948          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1949          * @param $short Boolean short circuit on first error
1950          *
1951          * @return Array list of errors
1952          */
1953         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1954                 // Account creation blocks handled at userlogin.
1955                 // Unblocking handled in SpecialUnblock
1956                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1957                         return $errors;
1958                 }
1959
1960                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1961
1962                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1963                         $errors[] = array( 'confirmedittext' );
1964                 }
1965
1966                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1967                         // Don't block the user from editing their own talk page unless they've been
1968                         // explicitly blocked from that too.
1969                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1970                         $block = $user->getBlock();
1971
1972                         // This is from OutputPage::blockedPage
1973                         // Copied at r23888 by werdna
1974
1975                         $id = $user->blockedBy();
1976                         $reason = $user->blockedFor();
1977                         if ( $reason == '' ) {
1978                                 $reason = wfMsg( 'blockednoreason' );
1979                         }
1980                         $ip = $user->getRequest()->getIP();
1981
1982                         if ( is_numeric( $id ) ) {
1983                                 $name = User::whoIs( $id );
1984                         } else {
1985                                 $name = $id;
1986                         }
1987
1988                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1989                         $blockid = $block->getId();
1990                         $blockExpiry = $block->getExpiry();
1991                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1992                         if ( $blockExpiry == 'infinity' ) {
1993                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1994                         } else {
1995                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1996                         }
1997
1998                         $intended = strval( $block->getTarget() );
1999
2000                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2001                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2002                 }
2003
2004                 return $errors;
2005         }
2006
2007         /**
2008          * Check that the user is allowed to read this page.
2009          *
2010          * @param $action String the action to check
2011          * @param $user User to check
2012          * @param $errors Array list of current errors
2013          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2014          * @param $short Boolean short circuit on first error
2015          *
2016          * @return Array list of errors
2017          */
2018         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2019                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2020                 static $useShortcut = null;
2021
2022                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2023                 if ( is_null( $useShortcut ) ) {
2024                         $useShortcut = true;
2025                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2026                                 # Not a public wiki, so no shortcut
2027                                 $useShortcut = false;
2028                         } elseif ( !empty( $wgRevokePermissions ) ) {
2029                                 /**
2030                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2031                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2032                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2033                                  * reading is allowed.
2034                                  */
2035                                 foreach ( $wgRevokePermissions as $perms ) {
2036                                         if ( !empty( $perms['read'] ) ) {
2037                                                 # We might be removing the read right from the user, so no shortcut
2038                                                 $useShortcut = false;
2039                                                 break;
2040                                         }
2041                                 }
2042                         }
2043                 }
2044
2045                 $whitelisted = false;
2046                 if ( $useShortcut ) {
2047                         # Shortcut for public wikis, allows skipping quite a bit of code
2048                         $whitelisted = true;
2049                 } elseif ( $user->isAllowed( 'read' ) ) {
2050                         # If the user is allowed to read pages, he is allowed to read all pages
2051                         $whitelisted = true;
2052                 } elseif ( $this->isSpecial( 'Userlogin' )
2053                         || $this->isSpecial( 'ChangePassword' )
2054                         || $this->isSpecial( 'PasswordReset' )
2055                 ) {
2056                         # Always grant access to the login page.
2057                         # Even anons need to be able to log in.
2058                         $whitelisted = true;
2059                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2060                         # Time to check the whitelist
2061                         # Only do these checks is there's something to check against
2062                         $name = $this->getPrefixedText();
2063                         $dbName = $this->getPrefixedDBKey();
2064
2065                         // Check for explicit whitelisting with and without underscores
2066                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2067                                 $whitelisted = true;
2068                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2069                                 # Old settings might have the title prefixed with
2070                                 # a colon for main-namespace pages
2071                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2072                                         $whitelisted = true;
2073                                 }
2074                         } elseif ( $this->isSpecialPage() ) {
2075                                 # If it's a special page, ditch the subpage bit and check again
2076                                 $name = $this->getDBkey();
2077                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2078                                 if ( $name !== false ) {
2079                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2080                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2081                                                 $whitelisted = true;
2082                                         }
2083                                 }
2084                         }
2085                 }
2086
2087                 if ( !$whitelisted ) {
2088                         # If the title is not whitelisted, give extensions a chance to do so...
2089                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2090                         if ( !$whitelisted ) {
2091                                 $errors[] = $this->missingPermissionError( $action, $short );
2092                         }
2093                 }
2094
2095                 return $errors;
2096         }
2097
2098         /**
2099          * Get a description array when the user doesn't have the right to perform
2100          * $action (i.e. when User::isAllowed() returns false)
2101          *
2102          * @param $action String the action to check
2103          * @param $short Boolean short circuit on first error
2104          * @return Array list of errors
2105          */
2106         private function missingPermissionError( $action, $short ) {
2107                 // We avoid expensive display logic for quickUserCan's and such
2108                 if ( $short ) {
2109                         return array( 'badaccess-group0' );
2110                 }
2111
2112                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2113                         User::getGroupsWithPermission( $action ) );
2114
2115                 if ( count( $groups ) ) {
2116                         global $wgLang;
2117                         return array(
2118                                 'badaccess-groups',
2119                                 $wgLang->commaList( $groups ),
2120                                 count( $groups )
2121                         );
2122                 } else {
2123                         return array( 'badaccess-group0' );
2124                 }
2125         }
2126
2127         /**
2128          * Can $user perform $action on this page? This is an internal function,
2129          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2130          * checks on wfReadOnly() and blocks)
2131          *
2132          * @param $action String action that permission needs to be checked for
2133          * @param $user User to check
2134          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2135          * @param $short Bool Set this to true to stop after the first permission error.
2136          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2137          */
2138         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2139                 wfProfileIn( __METHOD__ );
2140
2141                 # Read has special handling
2142                 if ( $action == 'read' ) {
2143                         $checks = array(
2144                                 'checkPermissionHooks',
2145                                 'checkReadPermissions',
2146                         );
2147                 } else {
2148                         $checks = array(
2149                                 'checkQuickPermissions',
2150                                 'checkPermissionHooks',
2151                                 'checkSpecialsAndNSPermissions',
2152                                 'checkCSSandJSPermissions',
2153                                 'checkPageRestrictions',
2154                                 'checkCascadingSourcesRestrictions',
2155                                 'checkActionPermissions',
2156                                 'checkUserBlock'
2157                         );
2158                 }
2159
2160                 $errors = array();
2161                 while( count( $checks ) > 0 &&
2162                                 !( $short && count( $errors ) > 0 ) ) {
2163                         $method = array_shift( $checks );
2164                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2165                 }
2166
2167                 wfProfileOut( __METHOD__ );
2168                 return $errors;
2169         }
2170
2171         /**
2172          * Protect css subpages of user pages: can $wgUser edit
2173          * this page?
2174          *
2175          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2176          * @return Bool
2177          */
2178         public function userCanEditCssSubpage() {
2179                 global $wgUser;
2180                 wfDeprecated( __METHOD__, '1.19' );
2181                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2182                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2183         }
2184
2185         /**
2186          * Protect js subpages of user pages: can $wgUser edit
2187          * this page?
2188          *
2189          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2190          * @return Bool
2191          */
2192         public function userCanEditJsSubpage() {
2193                 global $wgUser;
2194                 wfDeprecated( __METHOD__, '1.19' );
2195                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2196                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2197         }
2198
2199         /**
2200          * Get a filtered list of all restriction types supported by this wiki.
2201          * @param bool $exists True to get all restriction types that apply to
2202          * titles that do exist, False for all restriction types that apply to
2203          * titles that do not exist
2204          * @return array
2205          */
2206         public static function getFilteredRestrictionTypes( $exists = true ) {
2207                 global $wgRestrictionTypes;
2208                 $types = $wgRestrictionTypes;
2209                 if ( $exists ) {
2210                         # Remove the create restriction for existing titles
2211                         $types = array_diff( $types, array( 'create' ) );
2212                 } else {
2213                         # Only the create and upload restrictions apply to non-existing titles
2214                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2215                 }
2216                 return $types;
2217         }
2218
2219         /**
2220          * Returns restriction types for the current Title
2221          *
2222          * @return array applicable restriction types
2223          */
2224         public function getRestrictionTypes() {
2225                 if ( $this->isSpecialPage() ) {
2226                         return array();
2227                 }
2228
2229                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2230
2231                 if ( $this->getNamespace() != NS_FILE ) {
2232                         # Remove the upload restriction for non-file titles
2233                         $types = array_diff( $types, array( 'upload' ) );
2234                 }
2235
2236                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2237
2238                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2239                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2240
2241                 return $types;
2242         }
2243
2244         /**
2245          * Is this title subject to title protection?
2246          * Title protection is the one applied against creation of such title.
2247          *
2248          * @return Mixed An associative array representing any existent title
2249          *   protection, or false if there's none.
2250          */
2251         private function getTitleProtection() {
2252                 // Can't protect pages in special namespaces
2253                 if ( $this->getNamespace() < 0 ) {
2254                         return false;
2255                 }
2256
2257                 // Can't protect pages that exist.
2258                 if ( $this->exists() ) {
2259                         return false;
2260                 }
2261
2262                 if ( !isset( $this->mTitleProtection ) ) {
2263                         $dbr = wfGetDB( DB_SLAVE );
2264                         $res = $dbr->select( 'protected_titles', '*',
2265                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2266                                 __METHOD__ );
2267
2268                         // fetchRow returns false if there are no rows.
2269                         $this->mTitleProtection = $dbr->fetchRow( $res );
2270                 }
2271                 return $this->mTitleProtection;
2272         }
2273
2274         /**
2275          * Update the title protection status
2276          *
2277          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2278          * @param $create_perm String Permission required for creation
2279          * @param $reason String Reason for protection
2280          * @param $expiry String Expiry timestamp
2281          * @return boolean true
2282          */
2283         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2284                 wfDeprecated( __METHOD__, '1.19' );
2285
2286                 global $wgUser;
2287
2288                 $limit = array( 'create' => $create_perm );
2289                 $expiry = array( 'create' => $expiry );
2290
2291                 $page = WikiPage::factory( $this );
2292                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2293
2294                 return $status->isOK();
2295         }
2296
2297         /**
2298          * Remove any title protection due to page existing
2299          */
2300         public function deleteTitleProtection() {
2301                 $dbw = wfGetDB( DB_MASTER );
2302
2303                 $dbw->delete(
2304                         'protected_titles',
2305                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2306                         __METHOD__
2307                 );
2308                 $this->mTitleProtection = false;
2309         }
2310
2311         /**
2312          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2313          *
2314          * @param $action String Action to check (default: edit)
2315          * @return Bool
2316          */
2317         public function isSemiProtected( $action = 'edit' ) {
2318                 if ( $this->exists() ) {
2319                         $restrictions = $this->getRestrictions( $action );
2320                         if ( count( $restrictions ) > 0 ) {
2321                                 foreach ( $restrictions as $restriction ) {
2322                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2323                                                 return false;
2324                                         }
2325                                 }
2326                         } else {
2327                                 # Not protected
2328                                 return false;
2329                         }
2330                         return true;
2331                 } else {
2332                         # If it doesn't exist, it can't be protected
2333                         return false;
2334                 }
2335         }
2336
2337         /**
2338          * Does the title correspond to a protected article?
2339          *
2340          * @param $action String the action the page is protected from,
2341          * by default checks all actions.
2342          * @return Bool
2343          */
2344         public function isProtected( $action = '' ) {
2345                 global $wgRestrictionLevels;
2346
2347                 $restrictionTypes = $this->getRestrictionTypes();
2348
2349                 # Special pages have inherent protection
2350                 if( $this->isSpecialPage() ) {
2351                         return true;
2352                 }
2353
2354                 # Check regular protection levels
2355                 foreach ( $restrictionTypes as $type ) {
2356                         if ( $action == $type || $action == '' ) {
2357                                 $r = $this->getRestrictions( $type );
2358                                 foreach ( $wgRestrictionLevels as $level ) {
2359                                         if ( in_array( $level, $r ) && $level != '' ) {
2360                                                 return true;
2361                                         }
2362                                 }
2363                         }
2364                 }
2365
2366                 return false;
2367         }
2368
2369         /**
2370          * Determines if $user is unable to edit this page because it has been protected
2371          * by $wgNamespaceProtection.
2372          *
2373          * @param $user User object to check permissions
2374          * @return Bool
2375          */
2376         public function isNamespaceProtected( User $user ) {
2377                 global $wgNamespaceProtection;
2378
2379                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2380                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2381                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2382                                         return true;
2383                                 }
2384                         }
2385                 }
2386                 return false;
2387         }
2388
2389         /**
2390          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2391          *
2392          * @return Bool If the page is subject to cascading restrictions.
2393          */
2394         public function isCascadeProtected() {
2395                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2396                 return ( $sources > 0 );
2397         }
2398
2399         /**
2400          * Cascading protection: Get the source of any cascading restrictions on this page.
2401          *
2402          * @param $getPages Bool Whether or not to retrieve the actual pages
2403          *        that the restrictions have come from.
2404          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2405          *     have come, false for none, or true if such restrictions exist, but $getPages
2406          *     was not set.  The restriction array is an array of each type, each of which
2407          *     contains a array of unique groups.
2408          */
2409         public function getCascadeProtectionSources( $getPages = true ) {
2410                 global $wgContLang;
2411                 $pagerestrictions = array();
2412
2413                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2414                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2415                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2416                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2417                 }
2418
2419                 wfProfileIn( __METHOD__ );
2420
2421                 $dbr = wfGetDB( DB_SLAVE );
2422
2423                 if ( $this->getNamespace() == NS_FILE ) {
2424                         $tables = array( 'imagelinks', 'page_restrictions' );
2425                         $where_clauses = array(
2426                                 'il_to' => $this->getDBkey(),
2427                                 'il_from=pr_page',
2428                                 'pr_cascade' => 1
2429                         );
2430                 } else {
2431                         $tables = array( 'templatelinks', 'page_restrictions' );
2432                         $where_clauses = array(
2433                                 'tl_namespace' => $this->getNamespace(),
2434                                 'tl_title' => $this->getDBkey(),
2435                                 'tl_from=pr_page',
2436                                 'pr_cascade' => 1
2437                         );
2438                 }
2439
2440                 if ( $getPages ) {
2441                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2442                                                    'pr_expiry', 'pr_type', 'pr_level' );
2443                         $where_clauses[] = 'page_id=pr_page';
2444                         $tables[] = 'page';
2445                 } else {
2446                         $cols = array( 'pr_expiry' );
2447                 }
2448
2449                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2450
2451                 $sources = $getPages ? array() : false;
2452                 $now = wfTimestampNow();
2453                 $purgeExpired = false;
2454
2455                 foreach ( $res as $row ) {
2456                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2457                         if ( $expiry > $now ) {
2458                                 if ( $getPages ) {
2459                                         $page_id = $row->pr_page;
2460                                         $page_ns = $row->page_namespace;
2461                                         $page_title = $row->page_title;
2462                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2463                                         # Add groups needed for each restriction type if its not already there
2464                                         # Make sure this restriction type still exists
2465
2466                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2467                                                 $pagerestrictions[$row->pr_type] = array();
2468                                         }
2469
2470                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2471                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2472                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2473                                         }
2474                                 } else {
2475                                         $sources = true;
2476                                 }
2477                         } else {
2478                                 // Trigger lazy purge of expired restrictions from the db
2479                                 $purgeExpired = true;
2480                         }
2481                 }
2482                 if ( $purgeExpired ) {
2483                         Title::purgeExpiredRestrictions();
2484                 }
2485
2486                 if ( $getPages ) {
2487                         $this->mCascadeSources = $sources;
2488                         $this->mCascadingRestrictions = $pagerestrictions;
2489                 } else {
2490                         $this->mHasCascadingRestrictions = $sources;
2491                 }
2492
2493                 wfProfileOut( __METHOD__ );
2494                 return array( $sources, $pagerestrictions );
2495         }
2496
2497         /**
2498          * Accessor/initialisation for mRestrictions
2499          *
2500          * @param $action String action that permission needs to be checked for
2501          * @return Array of Strings the array of groups allowed to edit this article
2502          */
2503         public function getRestrictions( $action ) {
2504                 if ( !$this->mRestrictionsLoaded ) {
2505                         $this->loadRestrictions();
2506                 }
2507                 return isset( $this->mRestrictions[$action] )
2508                                 ? $this->mRestrictions[$action]
2509                                 : array();
2510         }
2511
2512         /**
2513          * Get the expiry time for the restriction against a given action
2514          *
2515          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2516          *      or not protected at all, or false if the action is not recognised.
2517          */
2518         public function getRestrictionExpiry( $action ) {
2519                 if ( !$this->mRestrictionsLoaded ) {
2520                         $this->loadRestrictions();
2521                 }
2522                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2523         }
2524
2525         /**
2526          * Returns cascading restrictions for the current article
2527          *
2528          * @return Boolean
2529          */
2530         function areRestrictionsCascading() {
2531                 if ( !$this->mRestrictionsLoaded ) {
2532                         $this->loadRestrictions();
2533                 }
2534
2535                 return $this->mCascadeRestriction;
2536         }
2537
2538         /**
2539          * Loads a string into mRestrictions array
2540          *
2541          * @param $res Resource restrictions as an SQL result.
2542          * @param $oldFashionedRestrictions String comma-separated list of page
2543          *        restrictions from page table (pre 1.10)
2544          */
2545         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2546                 $rows = array();
2547
2548                 foreach ( $res as $row ) {
2549                         $rows[] = $row;
2550                 }
2551
2552                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2553         }
2554
2555         /**
2556          * Compiles list of active page restrictions from both page table (pre 1.10)
2557          * and page_restrictions table for this existing page.
2558          * Public for usage by LiquidThreads.
2559          *
2560          * @param $rows array of db result objects
2561          * @param $oldFashionedRestrictions string comma-separated list of page
2562          *        restrictions from page table (pre 1.10)
2563          */
2564         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2565                 global $wgContLang;
2566                 $dbr = wfGetDB( DB_SLAVE );
2567
2568                 $restrictionTypes = $this->getRestrictionTypes();
2569
2570                 foreach ( $restrictionTypes as $type ) {
2571                         $this->mRestrictions[$type] = array();
2572                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2573                 }
2574
2575                 $this->mCascadeRestriction = false;
2576
2577                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2578
2579                 if ( $oldFashionedRestrictions === null ) {
2580                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2581                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2582                 }
2583
2584                 if ( $oldFashionedRestrictions != '' ) {
2585
2586                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2587                                 $temp = explode( '=', trim( $restrict ) );
2588                                 if ( count( $temp ) == 1 ) {
2589                                         // old old format should be treated as edit/move restriction
2590                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2591                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2592                                 } else {
2593                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2594                                 }
2595                         }
2596
2597                         $this->mOldRestrictions = true;
2598
2599                 }
2600
2601                 if ( count( $rows ) ) {
2602                         # Current system - load second to make them override.
2603                         $now = wfTimestampNow();
2604                         $purgeExpired = false;
2605
2606                         # Cycle through all the restrictions.
2607                         foreach ( $rows as $row ) {
2608
2609                                 // Don't take care of restrictions types that aren't allowed
2610                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2611                                         continue;
2612
2613                                 // This code should be refactored, now that it's being used more generally,
2614                                 // But I don't really see any harm in leaving it in Block for now -werdna
2615                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2616
2617                                 // Only apply the restrictions if they haven't expired!
2618                                 if ( !$expiry || $expiry > $now ) {
2619                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2620                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2621
2622                                         $this->mCascadeRestriction |= $row->pr_cascade;
2623                                 } else {
2624                                         // Trigger a lazy purge of expired restrictions
2625                                         $purgeExpired = true;
2626                                 }
2627                         }
2628
2629                         if ( $purgeExpired ) {
2630                                 Title::purgeExpiredRestrictions();
2631                         }
2632                 }
2633
2634                 $this->mRestrictionsLoaded = true;
2635         }
2636
2637         /**
2638          * Load restrictions from the page_restrictions table
2639          *
2640          * @param $oldFashionedRestrictions String comma-separated list of page
2641          *        restrictions from page table (pre 1.10)
2642          */
2643         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2644                 global $wgContLang;
2645                 if ( !$this->mRestrictionsLoaded ) {
2646                         if ( $this->exists() ) {
2647                                 $dbr = wfGetDB( DB_SLAVE );
2648
2649                                 $res = $dbr->select(
2650                                         'page_restrictions',
2651                                         '*',
2652                                         array( 'pr_page' => $this->getArticleID() ),
2653                                         __METHOD__
2654                                 );
2655
2656                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2657                         } else {
2658                                 $title_protection = $this->getTitleProtection();
2659
2660                                 if ( $title_protection ) {
2661                                         $now = wfTimestampNow();
2662                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2663
2664                                         if ( !$expiry || $expiry > $now ) {
2665                                                 // Apply the restrictions
2666                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2667                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2668                                         } else { // Get rid of the old restrictions
2669                                                 Title::purgeExpiredRestrictions();
2670                                                 $this->mTitleProtection = false;
2671                                         }
2672                                 } else {
2673                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2674                                 }
2675                                 $this->mRestrictionsLoaded = true;
2676                         }
2677                 }
2678         }
2679
2680         /**
2681          * Flush the protection cache in this object and force reload from the database.
2682          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2683          */
2684         public function flushRestrictions() {
2685                 $this->mRestrictionsLoaded = false;
2686                 $this->mTitleProtection = null;
2687         }
2688
2689         /**
2690          * Purge expired restrictions from the page_restrictions table
2691          */
2692         static function purgeExpiredRestrictions() {
2693                 $dbw = wfGetDB( DB_MASTER );
2694                 $dbw->delete(
2695                         'page_restrictions',
2696                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2697                         __METHOD__
2698                 );
2699
2700                 $dbw->delete(
2701                         'protected_titles',
2702                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2703                         __METHOD__
2704                 );
2705         }
2706
2707         /**
2708          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2709          *
2710          * @return Bool
2711          */
2712         public function hasSubpages() {
2713                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2714                         # Duh
2715                         return false;
2716                 }
2717
2718                 # We dynamically add a member variable for the purpose of this method
2719                 # alone to cache the result.  There's no point in having it hanging
2720                 # around uninitialized in every Title object; therefore we only add it
2721                 # if needed and don't declare it statically.
2722                 if ( isset( $this->mHasSubpages ) ) {
2723                         return $this->mHasSubpages;
2724                 }
2725
2726                 $subpages = $this->getSubpages( 1 );
2727                 if ( $subpages instanceof TitleArray ) {
2728                         return $this->mHasSubpages = (bool)$subpages->count();
2729                 }
2730                 return $this->mHasSubpages = false;
2731         }
2732
2733         /**
2734          * Get all subpages of this page.
2735          *
2736          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2737          * @return mixed TitleArray, or empty array if this page's namespace
2738          *  doesn't allow subpages
2739          */
2740         public function getSubpages( $limit = -1 ) {
2741                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2742                         return array();
2743                 }
2744
2745                 $dbr = wfGetDB( DB_SLAVE );
2746                 $conds['page_namespace'] = $this->getNamespace();
2747                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2748                 $options = array();
2749                 if ( $limit > -1 ) {
2750                         $options['LIMIT'] = $limit;
2751                 }
2752                 return $this->mSubpages = TitleArray::newFromResult(
2753                         $dbr->select( 'page',
2754                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2755                                 $conds,
2756                                 __METHOD__,
2757                                 $options
2758                         )
2759                 );
2760         }
2761
2762         /**
2763          * Is there a version of this page in the deletion archive?
2764          *
2765          * @return Int the number of archived revisions
2766          */
2767         public function isDeleted() {
2768                 if ( $this->getNamespace() < 0 ) {
2769                         $n = 0;
2770                 } else {
2771                         $dbr = wfGetDB( DB_SLAVE );
2772
2773                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2774                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2775                                 __METHOD__
2776                         );
2777                         if ( $this->getNamespace() == NS_FILE ) {
2778                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2779                                         array( 'fa_name' => $this->getDBkey() ),
2780                                         __METHOD__
2781                                 );
2782                         }
2783                 }
2784                 return (int)$n;
2785         }
2786
2787         /**
2788          * Is there a version of this page in the deletion archive?
2789          *
2790          * @return Boolean
2791          */
2792         public function isDeletedQuick() {
2793                 if ( $this->getNamespace() < 0 ) {
2794                         return false;
2795                 }
2796                 $dbr = wfGetDB( DB_SLAVE );
2797                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2798                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2799                         __METHOD__
2800                 );
2801                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2802                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2803                                 array( 'fa_name' => $this->getDBkey() ),
2804                                 __METHOD__
2805                         );
2806                 }
2807                 return $deleted;
2808         }
2809
2810         /**
2811          * Get the article ID for this Title from the link cache,
2812          * adding it if necessary
2813          *
2814          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2815          *  for update
2816          * @return Int the ID
2817          */
2818         public function getArticleID( $flags = 0 ) {
2819                 if ( $this->getNamespace() < 0 ) {
2820                         return $this->mArticleID = 0;
2821                 }
2822                 $linkCache = LinkCache::singleton();
2823                 if ( $flags & self::GAID_FOR_UPDATE ) {
2824                         $oldUpdate = $linkCache->forUpdate( true );
2825                         $linkCache->clearLink( $this );
2826                         $this->mArticleID = $linkCache->addLinkObj( $this );
2827                         $linkCache->forUpdate( $oldUpdate );
2828                 } else {
2829                         if ( -1 == $this->mArticleID ) {
2830                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2831                         }
2832                 }
2833                 return $this->mArticleID;
2834         }
2835
2836         /**
2837          * Is this an article that is a redirect page?
2838          * Uses link cache, adding it if necessary
2839          *
2840          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2841          * @return Bool
2842          */
2843         public function isRedirect( $flags = 0 ) {
2844                 if ( !is_null( $this->mRedirect ) ) {
2845                         return $this->mRedirect;
2846                 }
2847                 # Calling getArticleID() loads the field from cache as needed
2848                 if ( !$this->getArticleID( $flags ) ) {
2849                         return $this->mRedirect = false;
2850                 }
2851                 $linkCache = LinkCache::singleton();
2852                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2853
2854                 return $this->mRedirect;
2855         }
2856
2857         /**
2858          * What is the length of this page?
2859          * Uses link cache, adding it if necessary
2860          *
2861          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2862          * @return Int
2863          */
2864         public function getLength( $flags = 0 ) {
2865                 if ( $this->mLength != -1 ) {
2866                         return $this->mLength;
2867                 }
2868                 # Calling getArticleID() loads the field from cache as needed
2869                 if ( !$this->getArticleID( $flags ) ) {
2870                         return $this->mLength = 0;
2871                 }
2872                 $linkCache = LinkCache::singleton();
2873                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2874
2875                 return $this->mLength;
2876         }
2877
2878         /**
2879          * What is the page_latest field for this page?
2880          *
2881          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2882          * @return Int or 0 if the page doesn't exist
2883          */
2884         public function getLatestRevID( $flags = 0 ) {
2885                 if ( $this->mLatestID !== false ) {
2886                         return intval( $this->mLatestID );
2887                 }
2888                 # Calling getArticleID() loads the field from cache as needed
2889                 if ( !$this->getArticleID( $flags ) ) {
2890                         return $this->mLatestID = 0;
2891                 }
2892                 $linkCache = LinkCache::singleton();
2893                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2894
2895                 return $this->mLatestID;
2896         }
2897
2898         /**
2899          * This clears some fields in this object, and clears any associated
2900          * keys in the "bad links" section of the link cache.
2901          *
2902          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2903          * loading of the new page_id. It's also called from
2904          * WikiPage::doDeleteArticle()
2905          *
2906          * @param $newid Int the new Article ID
2907          */
2908         public function resetArticleID( $newid ) {
2909                 $linkCache = LinkCache::singleton();
2910                 $linkCache->clearLink( $this );
2911
2912                 if ( $newid === false ) {
2913                         $this->mArticleID = -1;
2914                 } else {
2915                         $this->mArticleID = intval( $newid );
2916                 }
2917                 $this->mRestrictionsLoaded = false;
2918                 $this->mRestrictions = array();
2919                 $this->mRedirect = null;
2920                 $this->mLength = -1;
2921                 $this->mLatestID = false;
2922                 $this->mEstimateRevisions = null;
2923         }
2924
2925         /**
2926          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2927          *
2928          * @param $text String containing title to capitalize
2929          * @param $ns int namespace index, defaults to NS_MAIN
2930          * @return String containing capitalized title
2931          */
2932         public static function capitalize( $text, $ns = NS_MAIN ) {
2933                 global $wgContLang;
2934
2935                 if ( MWNamespace::isCapitalized( $ns ) ) {
2936                         return $wgContLang->ucfirst( $text );
2937                 } else {
2938                         return $text;
2939                 }
2940         }
2941
2942         /**
2943          * Secure and split - main initialisation function for this object
2944          *
2945          * Assumes that mDbkeyform has been set, and is urldecoded
2946          * and uses underscores, but not otherwise munged.  This function
2947          * removes illegal characters, splits off the interwiki and
2948          * namespace prefixes, sets the other forms, and canonicalizes
2949          * everything.
2950          *
2951          * @return Bool true on success
2952          */
2953         private function secureAndSplit() {
2954                 global $wgContLang, $wgLocalInterwiki;
2955
2956                 # Initialisation
2957                 $this->mInterwiki = $this->mFragment = '';
2958                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2959
2960                 $dbkey = $this->mDbkeyform;
2961
2962                 # Strip Unicode bidi override characters.
2963                 # Sometimes they slip into cut-n-pasted page titles, where the
2964                 # override chars get included in list displays.
2965                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2966
2967                 # Clean up whitespace
2968                 # Note: use of the /u option on preg_replace here will cause
2969                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2970                 # conveniently disabling them.
2971                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2972                 $dbkey = trim( $dbkey, '_' );
2973
2974                 if ( $dbkey == '' ) {
2975                         return false;
2976                 }
2977
2978                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2979                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2980                         return false;
2981                 }
2982
2983                 $this->mDbkeyform = $dbkey;
2984
2985                 # Initial colon indicates main namespace rather than specified default
2986                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2987                 if ( ':' == $dbkey[0] ) {
2988                         $this->mNamespace = NS_MAIN;
2989                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2990                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2991                 }
2992
2993                 # Namespace or interwiki prefix
2994                 $firstPass = true;
2995                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2996                 do {
2997                         $m = array();
2998                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2999                                 $p = $m[1];
3000                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3001                                         # Ordinary namespace
3002                                         $dbkey = $m[2];
3003                                         $this->mNamespace = $ns;
3004                                         # For Talk:X pages, check if X has a "namespace" prefix
3005                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3006                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3007                                                         # Disallow Talk:File:x type titles...
3008                                                         return false;
3009                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3010                                                         # Disallow Talk:Interwiki:x type titles...
3011                                                         return false;
3012                                                 }
3013                                         }
3014                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3015                                         if ( !$firstPass ) {
3016                                                 # Can't make a local interwiki link to an interwiki link.
3017                                                 # That's just crazy!
3018                                                 return false;
3019                                         }
3020
3021                                         # Interwiki link
3022                                         $dbkey = $m[2];
3023                                         $this->mInterwiki = $wgContLang->lc( $p );
3024
3025                                         # Redundant interwiki prefix to the local wiki
3026                                         if ( $wgLocalInterwiki !== false
3027                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3028                                         {
3029                                                 if ( $dbkey == '' ) {
3030                                                         # Can't have an empty self-link
3031                                                         return false;
3032                                                 }
3033                                                 $this->mInterwiki = '';
3034                                                 $firstPass = false;
3035                                                 # Do another namespace split...
3036                                                 continue;
3037                                         }
3038
3039                                         # If there's an initial colon after the interwiki, that also
3040                                         # resets the default namespace
3041                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3042                                                 $this->mNamespace = NS_MAIN;
3043                                                 $dbkey = substr( $dbkey, 1 );
3044                                         }
3045                                 }
3046                                 # If there's no recognized interwiki or namespace,
3047                                 # then let the colon expression be part of the title.
3048                         }
3049                         break;
3050                 } while ( true );
3051
3052                 # We already know that some pages won't be in the database!
3053                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3054                         $this->mArticleID = 0;
3055                 }
3056                 $fragment = strstr( $dbkey, '#' );
3057                 if ( false !== $fragment ) {
3058                         $this->setFragment( $fragment );
3059                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3060                         # remove whitespace again: prevents "Foo_bar_#"
3061                         # becoming "Foo_bar_"
3062                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3063                 }
3064
3065                 # Reject illegal characters.
3066                 $rxTc = self::getTitleInvalidRegex();
3067                 if ( preg_match( $rxTc, $dbkey ) ) {
3068                         return false;
3069                 }
3070
3071                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3072                 # reachable due to the way web browsers deal with 'relative' URLs.
3073                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3074                 if ( strpos( $dbkey, '.' ) !== false &&
3075                          ( $dbkey === '.' || $dbkey === '..' ||
3076                            strpos( $dbkey, './' ) === 0  ||
3077                            strpos( $dbkey, '../' ) === 0 ||
3078                            strpos( $dbkey, '/./' ) !== false ||
3079                            strpos( $dbkey, '/../' ) !== false  ||
3080                            substr( $dbkey, -2 ) == '/.' ||
3081                            substr( $dbkey, -3 ) == '/..' ) )
3082                 {
3083                         return false;
3084                 }
3085
3086                 # Magic tilde sequences? Nu-uh!
3087                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3088                         return false;
3089                 }
3090
3091                 # Limit the size of titles to 255 bytes. This is typically the size of the
3092                 # underlying database field. We make an exception for special pages, which
3093                 # don't need to be stored in the database, and may edge over 255 bytes due
3094                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3095                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3096                   strlen( $dbkey ) > 512 )
3097                 {
3098                         return false;
3099                 }
3100
3101                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3102                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3103                 # other site might be case-sensitive.
3104                 $this->mUserCaseDBKey = $dbkey;
3105                 if ( $this->mInterwiki == '' ) {
3106                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3107                 }
3108
3109                 # Can't make a link to a namespace alone... "empty" local links can only be
3110                 # self-links with a fragment identifier.
3111                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3112                         return false;
3113                 }
3114
3115                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3116                 // IP names are not allowed for accounts, and can only be referring to
3117                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3118                 // there are numerous ways to present the same IP. Having sp:contribs scan
3119                 // them all is silly and having some show the edits and others not is
3120                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3121                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3122                         ? IP::sanitizeIP( $dbkey )
3123                         : $dbkey;
3124
3125                 // Any remaining initial :s are illegal.
3126                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3127                         return false;
3128                 }
3129
3130                 # Fill fields
3131                 $this->mDbkeyform = $dbkey;
3132                 $this->mUrlform = wfUrlencode( $dbkey );
3133
3134                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3135
3136                 return true;
3137         }
3138
3139         /**
3140          * Get an array of Title objects linking to this Title
3141          * Also stores the IDs in the link cache.
3142          *
3143          * WARNING: do not use this function on arbitrary user-supplied titles!
3144          * On heavily-used templates it will max out the memory.
3145          *
3146          * @param $options Array: may be FOR UPDATE
3147          * @param $table String: table name
3148          * @param $prefix String: fields prefix
3149          * @return Array of Title objects linking here
3150          */
3151         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3152                 if ( count( $options ) > 0 ) {
3153                         $db = wfGetDB( DB_MASTER );
3154                 } else {
3155                         $db = wfGetDB( DB_SLAVE );
3156                 }
3157
3158                 $res = $db->select(
3159                         array( 'page', $table ),
3160                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3161                         array(
3162                                 "{$prefix}_from=page_id",
3163                                 "{$prefix}_namespace" => $this->getNamespace(),
3164                                 "{$prefix}_title"     => $this->getDBkey() ),
3165                         __METHOD__,
3166                         $options
3167                 );
3168
3169                 $retVal = array();
3170                 if ( $res->numRows() ) {
3171                         $linkCache = LinkCache::singleton();
3172                         foreach ( $res as $row ) {
3173                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3174                                 if ( $titleObj ) {
3175                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3176                                         $retVal[] = $titleObj;
3177                                 }
3178                         }
3179                 }
3180                 return $retVal;
3181         }
3182
3183         /**
3184          * Get an array of Title objects using this Title as a template
3185          * Also stores the IDs in the link cache.
3186          *
3187          * WARNING: do not use this function on arbitrary user-supplied titles!
3188          * On heavily-used templates it will max out the memory.
3189          *
3190          * @param $options Array: may be FOR UPDATE
3191          * @return Array of Title the Title objects linking here
3192          */
3193         public function getTemplateLinksTo( $options = array() ) {
3194                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3195         }
3196
3197         /**
3198          * Get an array of Title objects linked from this Title
3199          * Also stores the IDs in the link cache.
3200          *
3201          * WARNING: do not use this function on arbitrary user-supplied titles!
3202          * On heavily-used templates it will max out the memory.
3203          *
3204          * @param $options Array: may be FOR UPDATE
3205          * @param $table String: table name
3206          * @param $prefix String: fields prefix
3207          * @return Array of Title objects linking here
3208          */
3209         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3210                 $id = $this->getArticleID();
3211
3212                 # If the page doesn't exist; there can't be any link from this page
3213                 if ( !$id ) {
3214                         return array();
3215                 }
3216
3217                 if ( count( $options ) > 0 ) {
3218                         $db = wfGetDB( DB_MASTER );
3219                 } else {
3220                         $db = wfGetDB( DB_SLAVE );
3221                 }
3222
3223                 $namespaceFiled = "{$prefix}_namespace";
3224                 $titleField = "{$prefix}_title";
3225
3226                 $res = $db->select(
3227                         array( $table, 'page' ),
3228                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3229                         array( "{$prefix}_from" => $id ),
3230                         __METHOD__,
3231                         $options,
3232                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3233                 );
3234
3235                 $retVal = array();
3236                 if ( $res->numRows() ) {
3237                         $linkCache = LinkCache::singleton();
3238                         foreach ( $res as $row ) {
3239                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3240                                 if ( $titleObj ) {
3241                                         if ( $row->page_id ) {
3242                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3243                                         } else {
3244                                                 $linkCache->addBadLinkObj( $titleObj );
3245                                         }
3246                                         $retVal[] = $titleObj;
3247                                 }
3248                         }
3249                 }
3250                 return $retVal;
3251         }
3252
3253         /**
3254          * Get an array of Title objects used on this Title as a template
3255          * Also stores the IDs in the link cache.
3256          *
3257          * WARNING: do not use this function on arbitrary user-supplied titles!
3258          * On heavily-used templates it will max out the memory.
3259          *
3260          * @param $options Array: may be FOR UPDATE
3261          * @return Array of Title the Title objects used here
3262          */
3263         public function getTemplateLinksFrom( $options = array() ) {
3264                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3265         }
3266
3267         /**
3268          * Get an array of Title objects referring to non-existent articles linked from this page
3269          *
3270          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3271          * @return Array of Title the Title objects
3272          */
3273         public function getBrokenLinksFrom() {
3274                 if ( $this->getArticleID() == 0 ) {
3275                         # All links from article ID 0 are false positives
3276                         return array();
3277                 }
3278
3279                 $dbr = wfGetDB( DB_SLAVE );
3280                 $res = $dbr->select(
3281                         array( 'page', 'pagelinks' ),
3282                         array( 'pl_namespace', 'pl_title' ),
3283                         array(
3284                                 'pl_from' => $this->getArticleID(),
3285                                 'page_namespace IS NULL'
3286                         ),
3287                         __METHOD__, array(),
3288                         array(
3289                                 'page' => array(
3290                                         'LEFT JOIN',
3291                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3292                                 )
3293                         )
3294                 );
3295
3296                 $retVal = array();
3297                 foreach ( $res as $row ) {
3298                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3299                 }
3300                 return $retVal;
3301         }
3302
3303
3304         /**
3305          * Get a list of URLs to purge from the Squid cache when this
3306          * page changes
3307          *
3308          * @return Array of String the URLs
3309          */
3310         public function getSquidURLs() {
3311                 global $wgContLang;
3312
3313                 $urls = array(
3314                         $this->getInternalURL(),
3315                         $this->getInternalURL( 'action=history' )
3316                 );
3317
3318                 // purge variant urls as well
3319                 if ( $wgContLang->hasVariants() ) {
3320                         $variants = $wgContLang->getVariants();
3321                         foreach ( $variants as $vCode ) {
3322                                 $urls[] = $this->getInternalURL( '', $vCode );
3323                         }
3324                 }
3325
3326                 return $urls;
3327         }
3328
3329         /**
3330          * Purge all applicable Squid URLs
3331          */
3332         public function purgeSquid() {
3333                 global $wgUseSquid;
3334                 if ( $wgUseSquid ) {
3335                         $urls = $this->getSquidURLs();
3336                         $u = new SquidUpdate( $urls );
3337                         $u->doUpdate();
3338                 }
3339         }
3340
3341         /**
3342          * Move this page without authentication
3343          *
3344          * @param $nt Title the new page Title
3345          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3346          */
3347         public function moveNoAuth( &$nt ) {
3348                 return $this->moveTo( $nt, false );
3349         }
3350
3351         /**
3352          * Check whether a given move operation would be valid.
3353          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3354          *
3355          * @param $nt Title the new title
3356          * @param $auth Bool indicates whether $wgUser's permissions
3357          *  should be checked
3358          * @param $reason String is the log summary of the move, used for spam checking
3359          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3360          */
3361         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3362                 global $wgUser;
3363
3364                 $errors = array();
3365                 if ( !$nt ) {
3366                         // Normally we'd add this to $errors, but we'll get
3367                         // lots of syntax errors if $nt is not an object
3368                         return array( array( 'badtitletext' ) );
3369                 }
3370                 if ( $this->equals( $nt ) ) {
3371                         $errors[] = array( 'selfmove' );
3372                 }
3373                 if ( !$this->isMovable() ) {
3374                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3375                 }
3376                 if ( $nt->getInterwiki() != '' ) {
3377                         $errors[] = array( 'immobile-target-namespace-iw' );
3378                 }
3379                 if ( !$nt->isMovable() ) {
3380                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3381                 }
3382
3383                 $oldid = $this->getArticleID();
3384                 $newid = $nt->getArticleID();
3385
3386                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3387                         $errors[] = array( 'articleexists' );
3388                 }
3389                 if ( ( $this->getDBkey() == '' ) ||
3390                          ( !$oldid ) ||
3391                          ( $nt->getDBkey() == '' ) ) {
3392                         $errors[] = array( 'badarticleerror' );
3393                 }
3394
3395                 // Image-specific checks
3396                 if ( $this->getNamespace() == NS_FILE ) {
3397                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3398                 }
3399
3400                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3401                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3402                 }
3403
3404                 if ( $auth ) {
3405                         $errors = wfMergeErrorArrays( $errors,
3406                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3407                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3408                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3409                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3410                 }
3411
3412                 $match = EditPage::matchSummarySpamRegex( $reason );
3413                 if ( $match !== false ) {
3414                         // This is kind of lame, won't display nice
3415                         $errors[] = array( 'spamprotectiontext' );
3416                 }
3417
3418                 $err = null;
3419                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3420                         $errors[] = array( 'hookaborted', $err );
3421                 }
3422
3423                 # The move is allowed only if (1) the target doesn't exist, or
3424                 # (2) the target is a redirect to the source, and has no history
3425                 # (so we can undo bad moves right after they're done).
3426
3427                 if ( 0 != $newid ) { # Target exists; check for validity
3428                         if ( !$this->isValidMoveTarget( $nt ) ) {
3429                                 $errors[] = array( 'articleexists' );
3430                         }
3431                 } else {
3432                         $tp = $nt->getTitleProtection();
3433                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3434                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3435                                 $errors[] = array( 'cantmove-titleprotected' );
3436                         }
3437                 }
3438                 if ( empty( $errors ) ) {
3439                         return true;
3440                 }
3441                 return $errors;
3442         }
3443
3444         /**
3445          * Check if the requested move target is a valid file move target
3446          * @param Title $nt Target title
3447          * @return array List of errors
3448          */
3449         protected function validateFileMoveOperation( $nt ) {
3450                 global $wgUser;
3451
3452                 $errors = array();
3453
3454                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3455
3456                 $file = wfLocalFile( $this );
3457                 if ( $file->exists() ) {
3458                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3459                                 $errors[] = array( 'imageinvalidfilename' );
3460                         }
3461                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3462                                 $errors[] = array( 'imagetypemismatch' );
3463                         }
3464                 }
3465
3466                 if ( $nt->getNamespace() != NS_FILE ) {
3467                         $errors[] = array( 'imagenocrossnamespace' );
3468                         // From here we want to do checks on a file object, so if we can't
3469                         // create one, we must return.
3470                         return $errors;
3471                 }
3472
3473                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3474
3475                 $destFile = wfLocalFile( $nt );
3476                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3477                         $errors[] = array( 'file-exists-sharedrepo' );
3478                 }
3479
3480                 return $errors;
3481         }
3482
3483         /**
3484          * Move a title to a new location
3485          *
3486          * @param $nt Title the new title
3487          * @param $auth Bool indicates whether $wgUser's permissions
3488          *  should be checked
3489          * @param $reason String the reason for the move
3490          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3491          *  Ignored if the user doesn't have the suppressredirect right.
3492          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3493          */
3494         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3495                 global $wgUser;
3496                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3497                 if ( is_array( $err ) ) {
3498                         // Auto-block user's IP if the account was "hard" blocked
3499                         $wgUser->spreadAnyEditBlock();
3500                         return $err;
3501                 }
3502
3503                 // If it is a file, move it first.
3504                 // It is done before all other moving stuff is done because it's hard to revert.
3505                 $dbw = wfGetDB( DB_MASTER );
3506                 if ( $this->getNamespace() == NS_FILE ) {
3507                         $file = wfLocalFile( $this );
3508                         if ( $file->exists() ) {
3509                                 $status = $file->move( $nt );
3510                                 if ( !$status->isOk() ) {
3511                                         return $status->getErrorsArray();
3512                                 }
3513                         }
3514                         // Clear RepoGroup process cache
3515                         RepoGroup::singleton()->clearCache( $this );
3516                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3517                 }
3518
3519                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3520                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3521                 $protected = $this->isProtected();
3522
3523                 // Do the actual move
3524                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3525                 if ( is_array( $err ) ) {
3526                         # @todo FIXME: What about the File we have already moved?
3527                         $dbw->rollback( __METHOD__ );
3528                         return $err;
3529                 }
3530
3531                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3532                 // cl_timestamp, which may disturb time-based lists on some sites.
3533                 $prefixes = $dbw->select(
3534                         'categorylinks',
3535                         array( 'cl_sortkey_prefix', 'cl_to' ),
3536                         array( 'cl_from' => $pageid ),
3537                         __METHOD__
3538                 );
3539                 foreach ( $prefixes as $prefixRow ) {
3540                         $prefix = $prefixRow->cl_sortkey_prefix;
3541                         $catTo = $prefixRow->cl_to;
3542                         $dbw->update( 'categorylinks',
3543                                 array(
3544                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3545                                                 $nt->getCategorySortkey( $prefix ) ),
3546                                         'cl_timestamp=cl_timestamp' ),
3547                                 array(
3548                                         'cl_from' => $pageid,
3549                                         'cl_to' => $catTo ),
3550                                 __METHOD__
3551                         );
3552                 }
3553
3554                 $redirid = $this->getArticleID();
3555
3556                 if ( $protected ) {
3557                         # Protect the redirect title as the title used to be...
3558                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3559                                 array(
3560                                         'pr_page'    => $redirid,
3561                                         'pr_type'    => 'pr_type',
3562                                         'pr_level'   => 'pr_level',
3563                                         'pr_cascade' => 'pr_cascade',
3564                                         'pr_user'    => 'pr_user',
3565                                         'pr_expiry'  => 'pr_expiry'
3566                                 ),
3567                                 array( 'pr_page' => $pageid ),
3568                                 __METHOD__,
3569                                 array( 'IGNORE' )
3570                         );
3571                         # Update the protection log
3572                         $log = new LogPage( 'protect' );
3573                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3574                         if ( $reason ) {
3575                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3576                         }
3577                         // @todo FIXME: $params?
3578                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3579                 }
3580
3581                 # Update watchlists
3582                 $oldnamespace = $this->getNamespace() & ~1;
3583                 $newnamespace = $nt->getNamespace() & ~1;
3584                 $oldtitle = $this->getDBkey();
3585                 $newtitle = $nt->getDBkey();
3586
3587                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3588                         WatchedItem::duplicateEntries( $this, $nt );
3589                 }
3590
3591                 $dbw->commit( __METHOD__ );
3592
3593                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3594                 return true;
3595         }
3596
3597         /**
3598          * Move page to a title which is either a redirect to the
3599          * source page or nonexistent
3600          *
3601          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3602          * @param $reason String The reason for the move
3603          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3604          *   if the user doesn't have the suppressredirect right
3605          */
3606         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3607                 global $wgUser, $wgContLang;
3608
3609                 if ( $nt->exists() ) {
3610                         $moveOverRedirect = true;
3611                         $logType = 'move_redir';
3612                 } else {
3613                         $moveOverRedirect = false;
3614                         $logType = 'move';
3615                 }
3616
3617                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3618
3619                 $logEntry = new ManualLogEntry( 'move', $logType );
3620                 $logEntry->setPerformer( $wgUser );
3621                 $logEntry->setTarget( $this );
3622                 $logEntry->setComment( $reason );
3623                 $logEntry->setParameters( array(
3624                         '4::target' => $nt->getPrefixedText(),
3625                         '5::noredir' => $redirectSuppressed ? '1': '0',
3626                 ) );
3627
3628                 $formatter = LogFormatter::newFromEntry( $logEntry );
3629                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3630                 $comment = $formatter->getPlainActionText();
3631                 if ( $reason ) {
3632                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3633                 }
3634                 # Truncate for whole multibyte characters.
3635                 $comment = $wgContLang->truncate( $comment, 255 );
3636
3637                 $oldid = $this->getArticleID();
3638
3639                 $dbw = wfGetDB( DB_MASTER );
3640
3641                 $newpage = WikiPage::factory( $nt );
3642
3643                 if ( $moveOverRedirect ) {
3644                         $newid = $nt->getArticleID();
3645
3646                         # Delete the old redirect. We don't save it to history since
3647                         # by definition if we've got here it's rather uninteresting.
3648                         # We have to remove it so that the next step doesn't trigger
3649                         # a conflict on the unique namespace+title index...
3650                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3651
3652                         $newpage->doDeleteUpdates( $newid );
3653                 }
3654
3655                 # Save a null revision in the page's history notifying of the move
3656                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3657                 if ( !is_object( $nullRevision ) ) {
3658                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3659                 }
3660                 $nullRevId = $nullRevision->insertOn( $dbw );
3661
3662                 # Change the name of the target page:
3663                 $dbw->update( 'page',
3664                         /* SET */ array(
3665                                 'page_namespace' => $nt->getNamespace(),
3666                                 'page_title'     => $nt->getDBkey(),
3667                         ),
3668                         /* WHERE */ array( 'page_id' => $oldid ),
3669                         __METHOD__
3670                 );
3671
3672                 $this->resetArticleID( 0 );
3673                 $nt->resetArticleID( $oldid );
3674
3675                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3676
3677                 wfRunHooks( 'NewRevisionFromEditComplete',
3678                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3679
3680                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3681
3682                 if ( !$moveOverRedirect ) {
3683                         WikiPage::onArticleCreate( $nt );
3684                 }
3685
3686                 # Recreate the redirect, this time in the other direction.
3687                 if ( $redirectSuppressed ) {
3688                         WikiPage::onArticleDelete( $this );
3689                 } else {
3690                         $mwRedir = MagicWord::get( 'redirect' );
3691                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3692                         $redirectArticle = WikiPage::factory( $this );
3693                         $newid = $redirectArticle->insertOn( $dbw );
3694                         if ( $newid ) { // sanity
3695                                 $redirectRevision = new Revision( array(
3696                                         'page'    => $newid,
3697                                         'comment' => $comment,
3698                                         'text'    => $redirectText ) );
3699                                 $redirectRevision->insertOn( $dbw );
3700                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3701
3702                                 wfRunHooks( 'NewRevisionFromEditComplete',
3703                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3704
3705                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3706                         }
3707                 }
3708
3709                 # Log the move
3710                 $logid = $logEntry->insert();
3711                 $logEntry->publish( $logid );
3712         }
3713
3714         /**
3715          * Move this page's subpages to be subpages of $nt
3716          *
3717          * @param $nt Title Move target
3718          * @param $auth bool Whether $wgUser's permissions should be checked
3719          * @param $reason string The reason for the move
3720          * @param $createRedirect bool Whether to create redirects from the old subpages to
3721          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3722          * @return mixed array with old page titles as keys, and strings (new page titles) or
3723          *     arrays (errors) as values, or an error array with numeric indices if no pages
3724          *     were moved
3725          */
3726         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3727                 global $wgMaximumMovedPages;
3728                 // Check permissions
3729                 if ( !$this->userCan( 'move-subpages' ) ) {
3730                         return array( 'cant-move-subpages' );
3731                 }
3732                 // Do the source and target namespaces support subpages?
3733                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3734                         return array( 'namespace-nosubpages',
3735                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3736                 }
3737                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3738                         return array( 'namespace-nosubpages',
3739                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3740                 }
3741
3742                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3743                 $retval = array();
3744                 $count = 0;
3745                 foreach ( $subpages as $oldSubpage ) {
3746                         $count++;
3747                         if ( $count > $wgMaximumMovedPages ) {
3748                                 $retval[$oldSubpage->getPrefixedTitle()] =
3749                                                 array( 'movepage-max-pages',
3750                                                         $wgMaximumMovedPages );
3751                                 break;
3752                         }
3753
3754                         // We don't know whether this function was called before
3755                         // or after moving the root page, so check both
3756                         // $this and $nt
3757                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3758                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3759                         {
3760                                 // When moving a page to a subpage of itself,
3761                                 // don't move it twice
3762                                 continue;
3763                         }
3764                         $newPageName = preg_replace(
3765                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3766                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3767                                         $oldSubpage->getDBkey() );
3768                         if ( $oldSubpage->isTalkPage() ) {
3769                                 $newNs = $nt->getTalkPage()->getNamespace();
3770                         } else {
3771                                 $newNs = $nt->getSubjectPage()->getNamespace();
3772                         }
3773                         # Bug 14385: we need makeTitleSafe because the new page names may
3774                         # be longer than 255 characters.
3775                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3776
3777                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3778                         if ( $success === true ) {
3779                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3780                         } else {
3781                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3782                         }
3783                 }
3784                 return $retval;
3785         }
3786
3787         /**
3788          * Checks if this page is just a one-rev redirect.
3789          * Adds lock, so don't use just for light purposes.
3790          *
3791          * @return Bool
3792          */
3793         public function isSingleRevRedirect() {
3794                 $dbw = wfGetDB( DB_MASTER );
3795                 # Is it a redirect?
3796                 $row = $dbw->selectRow( 'page',
3797                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3798                         $this->pageCond(),
3799                         __METHOD__,
3800                         array( 'FOR UPDATE' )
3801                 );
3802                 # Cache some fields we may want
3803                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3804                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3805                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3806                 if ( !$this->mRedirect ) {
3807                         return false;
3808                 }
3809                 # Does the article have a history?
3810                 $row = $dbw->selectField( array( 'page', 'revision' ),
3811                         'rev_id',
3812                         array( 'page_namespace' => $this->getNamespace(),
3813                                 'page_title' => $this->getDBkey(),
3814                                 'page_id=rev_page',
3815                                 'page_latest != rev_id'
3816                         ),
3817                         __METHOD__,
3818                         array( 'FOR UPDATE' )
3819                 );
3820                 # Return true if there was no history
3821                 return ( $row === false );
3822         }
3823
3824         /**
3825          * Checks if $this can be moved to a given Title
3826          * - Selects for update, so don't call it unless you mean business
3827          *
3828          * @param $nt Title the new title to check
3829          * @return Bool
3830          */
3831         public function isValidMoveTarget( $nt ) {
3832                 # Is it an existing file?
3833                 if ( $nt->getNamespace() == NS_FILE ) {
3834                         $file = wfLocalFile( $nt );
3835                         if ( $file->exists() ) {
3836                                 wfDebug( __METHOD__ . ": file exists\n" );
3837                                 return false;
3838                         }
3839                 }
3840                 # Is it a redirect with no history?
3841                 if ( !$nt->isSingleRevRedirect() ) {
3842                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3843                         return false;
3844                 }
3845                 # Get the article text
3846                 $rev = Revision::newFromTitle( $nt );
3847                 if( !is_object( $rev ) ){
3848                         return false;
3849                 }
3850                 $text = $rev->getText();
3851                 # Does the redirect point to the source?
3852                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3853                 $m = array();
3854                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3855                         $redirTitle = Title::newFromText( $m[1] );
3856                         if ( !is_object( $redirTitle ) ||
3857                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3858                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3859                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3860                                 return false;
3861                         }
3862                 } else {
3863                         # Fail safe
3864                         wfDebug( __METHOD__ . ": failsafe\n" );
3865                         return false;
3866                 }
3867                 return true;
3868         }
3869
3870         /**
3871          * Get categories to which this Title belongs and return an array of
3872          * categories' names.
3873          *
3874          * @return Array of parents in the form:
3875          *        $parent => $currentarticle
3876          */
3877         public function getParentCategories() {
3878                 global $wgContLang;
3879
3880                 $data = array();
3881
3882                 $titleKey = $this->getArticleID();
3883
3884                 if ( $titleKey === 0 ) {
3885                         return $data;
3886                 }
3887
3888                 $dbr = wfGetDB( DB_SLAVE );
3889
3890                 $res = $dbr->select( 'categorylinks', '*',
3891                         array(
3892                                 'cl_from' => $titleKey,
3893                         ),
3894                         __METHOD__,
3895                         array()
3896                 );
3897
3898                 if ( $dbr->numRows( $res ) > 0 ) {
3899                         foreach ( $res as $row ) {
3900                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3901                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3902                         }
3903                 }
3904                 return $data;
3905         }
3906
3907         /**
3908          * Get a tree of parent categories
3909          *
3910          * @param $children Array with the children in the keys, to check for circular refs
3911          * @return Array Tree of parent categories
3912          */
3913         public function getParentCategoryTree( $children = array() ) {
3914                 $stack = array();
3915                 $parents = $this->getParentCategories();
3916
3917                 if ( $parents ) {
3918                         foreach ( $parents as $parent => $current ) {
3919                                 if ( array_key_exists( $parent, $children ) ) {
3920                                         # Circular reference
3921                                         $stack[$parent] = array();
3922                                 } else {
3923                                         $nt = Title::newFromText( $parent );
3924                                         if ( $nt ) {
3925                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3926                                         }
3927                                 }
3928                         }
3929                 }
3930
3931                 return $stack;
3932         }
3933
3934         /**
3935          * Get an associative array for selecting this title from
3936          * the "page" table
3937          *
3938          * @return Array suitable for the $where parameter of DB::select()
3939          */
3940         public function pageCond() {
3941                 if ( $this->mArticleID > 0 ) {
3942                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3943                         return array( 'page_id' => $this->mArticleID );
3944                 } else {
3945                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3946                 }
3947         }
3948
3949         /**
3950          * Get the revision ID of the previous revision
3951          *
3952          * @param $revId Int Revision ID. Get the revision that was before this one.
3953          * @param $flags Int Title::GAID_FOR_UPDATE
3954          * @return Int|Bool Old revision ID, or FALSE if none exists
3955          */
3956         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3957                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3958                 return $db->selectField( 'revision', 'rev_id',
3959                         array(
3960                                 'rev_page' => $this->getArticleID( $flags ),
3961                                 'rev_id < ' . intval( $revId )
3962                         ),
3963                         __METHOD__,
3964                         array( 'ORDER BY' => 'rev_id DESC' )
3965                 );
3966         }
3967
3968         /**
3969          * Get the revision ID of the next revision
3970          *
3971          * @param $revId Int Revision ID. Get the revision that was after this one.
3972          * @param $flags Int Title::GAID_FOR_UPDATE
3973          * @return Int|Bool Next revision ID, or FALSE if none exists
3974          */
3975         public function getNextRevisionID( $revId, $flags = 0 ) {
3976                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3977                 return $db->selectField( 'revision', 'rev_id',
3978                         array(
3979                                 'rev_page' => $this->getArticleID( $flags ),
3980                                 'rev_id > ' . intval( $revId )
3981                         ),
3982                         __METHOD__,
3983                         array( 'ORDER BY' => 'rev_id' )
3984                 );
3985         }
3986
3987         /**
3988          * Get the first revision of the page
3989          *
3990          * @param $flags Int Title::GAID_FOR_UPDATE
3991          * @return Revision|Null if page doesn't exist
3992          */
3993         public function getFirstRevision( $flags = 0 ) {
3994                 $pageId = $this->getArticleID( $flags );
3995                 if ( $pageId ) {
3996                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3997                         $row = $db->selectRow( 'revision', '*',
3998                                 array( 'rev_page' => $pageId ),
3999                                 __METHOD__,
4000                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4001                         );
4002                         if ( $row ) {
4003                                 return new Revision( $row );
4004                         }
4005                 }
4006                 return null;
4007         }
4008
4009         /**
4010          * Get the oldest revision timestamp of this page
4011          *
4012          * @param $flags Int Title::GAID_FOR_UPDATE
4013          * @return String: MW timestamp
4014          */
4015         public function getEarliestRevTime( $flags = 0 ) {
4016                 $rev = $this->getFirstRevision( $flags );
4017                 return $rev ? $rev->getTimestamp() : null;
4018         }
4019
4020         /**
4021          * Check if this is a new page
4022          *
4023          * @return bool
4024          */
4025         public function isNewPage() {
4026                 $dbr = wfGetDB( DB_SLAVE );
4027                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4028         }
4029
4030         /**
4031          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4032          *
4033          * @return bool
4034          */
4035         public function isBigDeletion() {
4036                 global $wgDeleteRevisionsLimit;
4037
4038                 if ( !$wgDeleteRevisionsLimit ) {
4039                         return false;
4040                 }
4041
4042                 $revCount = $this->estimateRevisionCount();
4043                 return $revCount > $wgDeleteRevisionsLimit;
4044         }
4045
4046         /**
4047          * Get the  approximate revision count of this page.
4048          *
4049          * @return int
4050          */
4051         public function estimateRevisionCount() {
4052                 if ( !$this->exists() ) {
4053                         return 0;
4054                 }
4055
4056                 if ( $this->mEstimateRevisions === null ) {
4057                         $dbr = wfGetDB( DB_SLAVE );
4058                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4059                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4060                 }
4061
4062                 return $this->mEstimateRevisions;
4063         }
4064
4065         /**
4066          * Get the number of revisions between the given revision.
4067          * Used for diffs and other things that really need it.
4068          *
4069          * @param $old int|Revision Old revision or rev ID (first before range)
4070          * @param $new int|Revision New revision or rev ID (first after range)
4071          * @return Int Number of revisions between these revisions.
4072          */
4073         public function countRevisionsBetween( $old, $new ) {
4074                 if ( !( $old instanceof Revision ) ) {
4075                         $old = Revision::newFromTitle( $this, (int)$old );
4076                 }
4077                 if ( !( $new instanceof Revision ) ) {
4078                         $new = Revision::newFromTitle( $this, (int)$new );
4079                 }
4080                 if ( !$old || !$new ) {
4081                         return 0; // nothing to compare
4082                 }
4083                 $dbr = wfGetDB( DB_SLAVE );
4084                 return (int)$dbr->selectField( 'revision', 'count(*)',
4085                         array(
4086                                 'rev_page' => $this->getArticleID(),
4087                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4088                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4089                         ),
4090                         __METHOD__
4091                 );
4092         }
4093
4094         /**
4095          * Get the number of authors between the given revision IDs.
4096          * Used for diffs and other things that really need it.
4097          *
4098          * @param $old int|Revision Old revision or rev ID (first before range)
4099          * @param $new int|Revision New revision or rev ID (first after range)
4100          * @param $limit Int Maximum number of authors
4101          * @return Int Number of revision authors between these revisions.
4102          */
4103         public function countAuthorsBetween( $old, $new, $limit ) {
4104                 if ( !( $old instanceof Revision ) ) {
4105                         $old = Revision::newFromTitle( $this, (int)$old );
4106                 }
4107                 if ( !( $new instanceof Revision ) ) {
4108                         $new = Revision::newFromTitle( $this, (int)$new );
4109                 }
4110                 if ( !$old || !$new ) {
4111                         return 0; // nothing to compare
4112                 }
4113                 $dbr = wfGetDB( DB_SLAVE );
4114                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4115                         array(
4116                                 'rev_page' => $this->getArticleID(),
4117                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4118                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4119                         ), __METHOD__,
4120                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4121                 );
4122                 return (int)$dbr->numRows( $res );
4123         }
4124
4125         /**
4126          * Compare with another title.
4127          *
4128          * @param $title Title
4129          * @return Bool
4130          */
4131         public function equals( Title $title ) {
4132                 // Note: === is necessary for proper matching of number-like titles.
4133                 return $this->getInterwiki() === $title->getInterwiki()
4134                         && $this->getNamespace() == $title->getNamespace()
4135                         && $this->getDBkey() === $title->getDBkey();
4136         }
4137
4138         /**
4139          * Check if this title is a subpage of another title
4140          *
4141          * @param $title Title
4142          * @return Bool
4143          */
4144         public function isSubpageOf( Title $title ) {
4145                 return $this->getInterwiki() === $title->getInterwiki()
4146                         && $this->getNamespace() == $title->getNamespace()
4147                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4148         }
4149
4150         /**
4151          * Check if page exists.  For historical reasons, this function simply
4152          * checks for the existence of the title in the page table, and will
4153          * thus return false for interwiki links, special pages and the like.
4154          * If you want to know if a title can be meaningfully viewed, you should
4155          * probably call the isKnown() method instead.
4156          *
4157          * @return Bool
4158          */
4159         public function exists() {
4160                 return $this->getArticleID() != 0;
4161         }
4162
4163         /**
4164          * Should links to this title be shown as potentially viewable (i.e. as
4165          * "bluelinks"), even if there's no record by this title in the page
4166          * table?
4167          *
4168          * This function is semi-deprecated for public use, as well as somewhat
4169          * misleadingly named.  You probably just want to call isKnown(), which
4170          * calls this function internally.
4171          *
4172          * (ISSUE: Most of these checks are cheap, but the file existence check
4173          * can potentially be quite expensive.  Including it here fixes a lot of
4174          * existing code, but we might want to add an optional parameter to skip
4175          * it and any other expensive checks.)
4176          *
4177          * @return Bool
4178          */
4179         public function isAlwaysKnown() {
4180                 $isKnown = null;
4181
4182                 /**
4183                  * Allows overriding default behaviour for determining if a page exists.
4184                  * If $isKnown is kept as null, regular checks happen. If it's
4185                  * a boolean, this value is returned by the isKnown method.
4186                  *
4187                  * @since 1.20
4188                  *
4189                  * @param Title $title
4190                  * @param boolean|null $isKnown
4191                  */
4192                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4193
4194                 if ( !is_null( $isKnown ) ) {
4195                         return $isKnown;
4196                 }
4197
4198                 if ( $this->mInterwiki != '' ) {
4199                         return true;  // any interwiki link might be viewable, for all we know
4200                 }
4201
4202                 switch( $this->mNamespace ) {
4203                         case NS_MEDIA:
4204                         case NS_FILE:
4205                                 // file exists, possibly in a foreign repo
4206                                 return (bool)wfFindFile( $this );
4207                         case NS_SPECIAL:
4208                                 // valid special page
4209                                 return SpecialPageFactory::exists( $this->getDBkey() );
4210                         case NS_MAIN:
4211                                 // selflink, possibly with fragment
4212                                 return $this->mDbkeyform == '';
4213                         case NS_MEDIAWIKI:
4214                                 // known system message
4215                                 return $this->hasSourceText() !== false;
4216                         default:
4217                                 return false;
4218                 }
4219         }
4220
4221         /**
4222          * Does this title refer to a page that can (or might) be meaningfully
4223          * viewed?  In particular, this function may be used to determine if
4224          * links to the title should be rendered as "bluelinks" (as opposed to
4225          * "redlinks" to non-existent pages).
4226          * Adding something else to this function will cause inconsistency
4227          * since LinkHolderArray calls isAlwaysKnown() and does its own
4228          * page existence check.
4229          *
4230          * @return Bool
4231          */
4232         public function isKnown() {
4233                 return $this->isAlwaysKnown() || $this->exists();
4234         }
4235
4236         /**
4237          * Does this page have source text?
4238          *
4239          * @return Boolean
4240          */
4241         public function hasSourceText() {
4242                 if ( $this->exists() ) {
4243                         return true;
4244                 }
4245
4246                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4247                         // If the page doesn't exist but is a known system message, default
4248                         // message content will be displayed, same for language subpages-
4249                         // Use always content language to avoid loading hundreds of languages
4250                         // to get the link color.
4251                         global $wgContLang;
4252                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4253                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4254                         return $message->exists();
4255                 }
4256
4257                 return false;
4258         }
4259
4260         /**
4261          * Get the default message text or false if the message doesn't exist
4262          *
4263          * @return String or false
4264          */
4265         public function getDefaultMessageText() {
4266                 global $wgContLang;
4267
4268                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4269                         return false;
4270                 }
4271
4272                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4273                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4274
4275                 if ( $message->exists() ) {
4276                         return $message->plain();
4277                 } else {
4278                         return false;
4279                 }
4280         }
4281
4282         /**
4283          * Updates page_touched for this page; called from LinksUpdate.php
4284          *
4285          * @return Bool true if the update succeded
4286          */
4287         public function invalidateCache() {
4288                 if ( wfReadOnly() ) {
4289                         return false;
4290                 }
4291                 $dbw = wfGetDB( DB_MASTER );
4292                 $success = $dbw->update(
4293                         'page',
4294                         array( 'page_touched' => $dbw->timestamp() ),
4295                         $this->pageCond(),
4296                         __METHOD__
4297                 );
4298                 HTMLFileCache::clearFileCache( $this );
4299                 return $success;
4300         }
4301
4302         /**
4303          * Update page_touched timestamps and send squid purge messages for
4304          * pages linking to this title. May be sent to the job queue depending
4305          * on the number of links. Typically called on create and delete.
4306          */
4307         public function touchLinks() {
4308                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4309                 $u->doUpdate();
4310
4311                 if ( $this->getNamespace() == NS_CATEGORY ) {
4312                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4313                         $u->doUpdate();
4314                 }
4315         }
4316
4317         /**
4318          * Get the last touched timestamp
4319          *
4320          * @param $db DatabaseBase: optional db
4321          * @return String last-touched timestamp
4322          */
4323         public function getTouched( $db = null ) {
4324                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4325                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4326                 return $touched;
4327         }
4328
4329         /**
4330          * Get the timestamp when this page was updated since the user last saw it.
4331          *
4332          * @param $user User
4333          * @return String|Null
4334          */
4335         public function getNotificationTimestamp( $user = null ) {
4336                 global $wgUser, $wgShowUpdatedMarker;
4337                 // Assume current user if none given
4338                 if ( !$user ) {
4339                         $user = $wgUser;
4340                 }
4341                 // Check cache first
4342                 $uid = $user->getId();
4343                 // avoid isset here, as it'll return false for null entries
4344                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4345                         return $this->mNotificationTimestamp[$uid];
4346                 }
4347                 if ( !$uid || !$wgShowUpdatedMarker ) {
4348                         return $this->mNotificationTimestamp[$uid] = false;
4349                 }
4350                 // Don't cache too much!
4351                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4352                         $this->mNotificationTimestamp = array();
4353                 }
4354                 $dbr = wfGetDB( DB_SLAVE );
4355                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4356                         'wl_notificationtimestamp',
4357                         array( 'wl_namespace' => $this->getNamespace(),
4358                                 'wl_title' => $this->getDBkey(),
4359                                 'wl_user' => $user->getId()
4360                         ),
4361                         __METHOD__
4362                 );
4363                 return $this->mNotificationTimestamp[$uid];
4364         }
4365
4366         /**
4367          * Generate strings used for xml 'id' names in monobook tabs
4368          *
4369          * @param $prepend string defaults to 'nstab-'
4370          * @return String XML 'id' name
4371          */
4372         public function getNamespaceKey( $prepend = 'nstab-' ) {
4373                 global $wgContLang;
4374                 // Gets the subject namespace if this title
4375                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4376                 // Checks if cononical namespace name exists for namespace
4377                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4378                         // Uses canonical namespace name
4379                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4380                 } else {
4381                         // Uses text of namespace
4382                         $namespaceKey = $this->getSubjectNsText();
4383                 }
4384                 // Makes namespace key lowercase
4385                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4386                 // Uses main
4387                 if ( $namespaceKey == '' ) {
4388                         $namespaceKey = 'main';
4389                 }
4390                 // Changes file to image for backwards compatibility
4391                 if ( $namespaceKey == 'file' ) {
4392                         $namespaceKey = 'image';
4393                 }
4394                 return $prepend . $namespaceKey;
4395         }
4396
4397         /**
4398          * Get all extant redirects to this Title
4399          *
4400          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4401          * @return Array of Title redirects to this title
4402          */
4403         public function getRedirectsHere( $ns = null ) {
4404                 $redirs = array();
4405
4406                 $dbr = wfGetDB( DB_SLAVE );
4407                 $where = array(
4408                         'rd_namespace' => $this->getNamespace(),
4409                         'rd_title' => $this->getDBkey(),
4410                         'rd_from = page_id'
4411                 );
4412                 if ( !is_null( $ns ) ) {
4413                         $where['page_namespace'] = $ns;
4414                 }
4415
4416                 $res = $dbr->select(
4417                         array( 'redirect', 'page' ),
4418                         array( 'page_namespace', 'page_title' ),
4419                         $where,
4420                         __METHOD__
4421                 );
4422
4423                 foreach ( $res as $row ) {
4424                         $redirs[] = self::newFromRow( $row );
4425                 }
4426                 return $redirs;
4427         }
4428
4429         /**
4430          * Check if this Title is a valid redirect target
4431          *
4432          * @return Bool
4433          */
4434         public function isValidRedirectTarget() {
4435                 global $wgInvalidRedirectTargets;
4436
4437                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4438                 if ( $this->isSpecial( 'Userlogout' ) ) {
4439                         return false;
4440                 }
4441
4442                 foreach ( $wgInvalidRedirectTargets as $target ) {
4443                         if ( $this->isSpecial( $target ) ) {
4444                                 return false;
4445                         }
4446                 }
4447
4448                 return true;
4449         }
4450
4451         /**
4452          * Get a backlink cache object
4453          *
4454          * @return BacklinkCache
4455          */
4456         function getBacklinkCache() {
4457                 if ( is_null( $this->mBacklinkCache ) ) {
4458                         $this->mBacklinkCache = new BacklinkCache( $this );
4459                 }
4460                 return $this->mBacklinkCache;
4461         }
4462
4463         /**
4464          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4465          *
4466          * @return Boolean
4467          */
4468         public function canUseNoindex() {
4469                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4470
4471                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4472                         ? $wgContentNamespaces
4473                         : $wgExemptFromUserRobotsControl;
4474
4475                 return !in_array( $this->mNamespace, $bannedNamespaces );
4476
4477         }
4478
4479         /**
4480          * Returns the raw sort key to be used for categories, with the specified
4481          * prefix.  This will be fed to Collation::getSortKey() to get a
4482          * binary sortkey that can be used for actual sorting.
4483          *
4484          * @param $prefix string The prefix to be used, specified using
4485          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4486          *   prefix.
4487          * @return string
4488          */
4489         public function getCategorySortkey( $prefix = '' ) {
4490                 $unprefixed = $this->getText();
4491
4492                 // Anything that uses this hook should only depend
4493                 // on the Title object passed in, and should probably
4494                 // tell the users to run updateCollations.php --force
4495                 // in order to re-sort existing category relations.
4496                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4497                 if ( $prefix !== '' ) {
4498                         # Separate with a line feed, so the unprefixed part is only used as
4499                         # a tiebreaker when two pages have the exact same prefix.
4500                         # In UCA, tab is the only character that can sort above LF
4501                         # so we strip both of them from the original prefix.
4502                         $prefix = strtr( $prefix, "\n\t", '  ' );
4503                         return "$prefix\n$unprefixed";
4504                 }
4505                 return $unprefixed;
4506         }
4507
4508         /**
4509          * Get the language in which the content of this page is written.
4510          * Defaults to $wgContLang, but in certain cases it can be e.g.
4511          * $wgLang (such as special pages, which are in the user language).
4512          *
4513          * @since 1.18
4514          * @return object Language
4515          */
4516         public function getPageLanguage() {
4517                 global $wgLang;
4518                 if ( $this->isSpecialPage() ) {
4519                         // special pages are in the user language
4520                         return $wgLang;
4521                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4522                         // css/js should always be LTR and is, in fact, English
4523                         return wfGetLangObj( 'en' );
4524                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4525                         // Parse mediawiki messages with correct target language
4526                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4527                         return wfGetLangObj( $lang );
4528                 }
4529                 global $wgContLang;
4530                 // If nothing special, it should be in the wiki content language
4531                 $pageLang = $wgContLang;
4532                 // Hook at the end because we don't want to override the above stuff
4533                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4534                 return wfGetLangObj( $pageLang );
4535         }
4536 }