includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  83                                                                           # Zero except in {{transclusion}} tags
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mHasSubpage;                 // /< Whether a page has any subpages
  89         // @}
  90
  91
  92         /**
  93          * Constructor
  94          */
  95         /*protected*/ function __construct() { }
  96
  97         /**
  98          * Create a new Title from a prefixed DB key
  99          *
 100          * @param $key String the database key, which has underscores
 101          *      instead of spaces, possibly including namespace and
 102          *      interwiki prefixes
 103          * @return Title, or NULL on an error
 104          */
 105         public static function newFromDBkey( $key ) {
 106                 $t = new Title();
 107                 $t->mDbkeyform = $key;
 108                 if ( $t->secureAndSplit() ) {
 109                         return $t;
 110                 } else {
 111                         return null;
 112                 }
 113         }
 114
 115         /**
 116          * Create a new Title from text, such as what one would find in a link. De-
 117          * codes any HTML entities in the text.
 118          *
 119          * @param $text String the link text; spaces, prefixes, and an
 120          *   initial ':' indicating the main namespace are accepted.
 121          * @param $defaultNamespace Int the namespace to use if none is speci-
 122          *   fied by a prefix.  If you want to force a specific namespace even if
 123          *   $text might begin with a namespace prefix, use makeTitle() or
 124          *   makeTitleSafe().
 125          * @throws MWException
 126          * @return Title|null - Title or null on an error.
 127          */
 128         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 129                 if ( is_object( $text ) ) {
 130                         throw new MWException( 'Title::newFromText given an object' );
 131                 }
 132
 133                 /**
 134                  * Wiki pages often contain multiple links to the same page.
 135                  * Title normalization and parsing can become expensive on
 136                  * pages with many links, so we can save a little time by
 137                  * caching them.
 138                  *
 139                  * In theory these are value objects and won't get changed...
 140                  */
 141                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 142                         return Title::$titleCache[$text];
 143                 }
 144
 145                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 146                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 147
 148                 $t = new Title();
 149                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 150                 $t->mDefaultNamespace = $defaultNamespace;
 151
 152                 static $cachedcount = 0 ;
 153                 if ( $t->secureAndSplit() ) {
 154                         if ( $defaultNamespace == NS_MAIN ) {
 155                                 if ( $cachedcount >= self::CACHE_MAX ) {
 156                                         # Avoid memory leaks on mass operations...
 157                                         Title::$titleCache = array();
 158                                         $cachedcount = 0;
 159                                 }
 160                                 $cachedcount++;
 161                                 Title::$titleCache[$text] =& $t;
 162                         }
 163                         return $t;
 164                 } else {
 165                         $ret = null;
 166                         return $ret;
 167                 }
 168         }
 169
 170         /**
 171          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 172          *
 173          * Example of wrong and broken code:
 174          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 175          *
 176          * Example of right code:
 177          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 178          *
 179          * Create a new Title from URL-encoded text. Ensures that
 180          * the given title's length does not exceed the maximum.
 181          *
 182          * @param $url String the title, as might be taken from a URL
 183          * @return Title the new object, or NULL on an error
 184          */
 185         public static function newFromURL( $url ) {
 186                 $t = new Title();
 187
 188                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 189                 # but some URLs used it as a space replacement and they still come
 190                 # from some external search tools.
 191                 if ( strpos( self::legalChars(), '+' ) === false ) {
 192                         $url = str_replace( '+', ' ', $url );
 193                 }
 194
 195                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 196                 if ( $t->secureAndSplit() ) {
 197                         return $t;
 198                 } else {
 199                         return null;
 200                 }
 201         }
 202
 203         /**
 204          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 205          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 206          *
 207          * @return array
 208          */
 209         protected static function getSelectFields() {
 210                 global $wgContentHandlerUseDB;
 211
 212                 $fields = array(
 213                         'page_namespace', 'page_title', 'page_id',
 214                         'page_len', 'page_is_redirect', 'page_latest',
 215                 );
 216
 217                 if ( $wgContentHandlerUseDB ) {
 218                         $fields[] = 'page_content_model';
 219                 }
 220
 221                 return $fields;
 222         }
 223
 224         /**
 225          * Create a new Title from an article ID
 226          *
 227          * @param $id Int the page_id corresponding to the Title to create
 228          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 229          * @return Title the new object, or NULL on an error
 230          */
 231         public static function newFromID( $id, $flags = 0 ) {
 232                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 233                 $row = $db->selectRow(
 234                         'page',
 235                         self::getSelectFields(),
 236                         array( 'page_id' => $id ),
 237                         __METHOD__
 238                 );
 239                 if ( $row !== false ) {
 240                         $title = Title::newFromRow( $row );
 241                 } else {
 242                         $title = null;
 243                 }
 244                 return $title;
 245         }
 246
 247         /**
 248          * Make an array of titles from an array of IDs
 249          *
 250          * @param $ids Array of Int Array of IDs
 251          * @return Array of Titles
 252          */
 253         public static function newFromIDs( $ids ) {
 254                 if ( !count( $ids ) ) {
 255                         return array();
 256                 }
 257                 $dbr = wfGetDB( DB_SLAVE );
 258
 259                 $res = $dbr->select(
 260                         'page',
 261                         self::getSelectFields(),
 262                         array( 'page_id' => $ids ),
 263                         __METHOD__
 264                 );
 265
 266                 $titles = array();
 267                 foreach ( $res as $row ) {
 268                         $titles[] = Title::newFromRow( $row );
 269                 }
 270                 return $titles;
 271         }
 272
 273         /**
 274          * Make a Title object from a DB row
 275          *
 276          * @param $row Object database row (needs at least page_title,page_namespace)
 277          * @return Title corresponding Title
 278          */
 279         public static function newFromRow( $row ) {
 280                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 281                 $t->loadFromRow( $row );
 282                 return $t;
 283         }
 284
 285         /**
 286          * Load Title object fields from a DB row.
 287          * If false is given, the title will be treated as non-existing.
 288          *
 289          * @param $row Object|bool database row
 290          */
 291         public function loadFromRow( $row ) {
 292                 if ( $row ) { // page found
 293                         if ( isset( $row->page_id ) )
 294                                 $this->mArticleID = (int)$row->page_id;
 295                         if ( isset( $row->page_len ) )
 296                                 $this->mLength = (int)$row->page_len;
 297                         if ( isset( $row->page_is_redirect ) )
 298                                 $this->mRedirect = (bool)$row->page_is_redirect;
 299                         if ( isset( $row->page_latest ) )
 300                                 $this->mLatestID = (int)$row->page_latest;
 301                         if ( isset( $row->page_content_model ) )
 302                                 $this->mContentModel = strval( $row->page_content_model );
 303                         else
 304                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 305                 } else { // page not found
 306                         $this->mArticleID = 0;
 307                         $this->mLength = 0;
 308                         $this->mRedirect = false;
 309                         $this->mLatestID = 0;
 310                         $this->mContentModel = false; # initialized lazily in getContentModel()
 311                 }
 312         }
 313
 314         /**
 315          * Create a new Title from a namespace index and a DB key.
 316          * It's assumed that $ns and $title are *valid*, for instance when
 317          * they came directly from the database or a special page name.
 318          * For convenience, spaces are converted to underscores so that
 319          * eg user_text fields can be used directly.
 320          *
 321          * @param $ns Int the namespace of the article
 322          * @param $title String the unprefixed database key form
 323          * @param $fragment String the link fragment (after the "#")
 324          * @param $interwiki String the interwiki prefix
 325          * @return Title the new object
 326          */
 327         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 328                 $t = new Title();
 329                 $t->mInterwiki = $interwiki;
 330                 $t->mFragment = $fragment;
 331                 $t->mNamespace = $ns = intval( $ns );
 332                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 333                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 334                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 335                 $t->mTextform = str_replace( '_', ' ', $title );
 336                 $t->mContentModel = false; # initialized lazily in getContentModel()
 337                 return $t;
 338         }
 339
 340         /**
 341          * Create a new Title from a namespace index and a DB key.
 342          * The parameters will be checked for validity, which is a bit slower
 343          * than makeTitle() but safer for user-provided data.
 344          *
 345          * @param $ns Int the namespace of the article
 346          * @param $title String database key form
 347          * @param $fragment String the link fragment (after the "#")
 348          * @param $interwiki String interwiki prefix
 349          * @return Title the new object, or NULL on an error
 350          */
 351         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 352                 if ( !MWNamespace::exists( $ns ) ) {
 353                         return null;
 354                 }
 355
 356                 $t = new Title();
 357                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 358                 if ( $t->secureAndSplit() ) {
 359                         return $t;
 360                 } else {
 361                         return null;
 362                 }
 363         }
 364
 365         /**
 366          * Create a new Title for the Main Page
 367          *
 368          * @return Title the new object
 369          */
 370         public static function newMainPage() {
 371                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 372                 // Don't give fatal errors if the message is broken
 373                 if ( !$title ) {
 374                         $title = Title::newFromText( 'Main Page' );
 375                 }
 376                 return $title;
 377         }
 378
 379         /**
 380          * Extract a redirect destination from a string and return the
 381          * Title, or null if the text doesn't contain a valid redirect
 382          * This will only return the very next target, useful for
 383          * the redirect table and other checks that don't need full recursion
 384          *
 385          * @param $text String: Text with possible redirect
 386          * @return Title: The corresponding Title
 387          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 388          */
 389         public static function newFromRedirect( $text ) {
 390                 ContentHandler::deprecated( __METHOD__, '1.21' );
 391
 392                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 393                 return $content->getRedirectTarget();
 394         }
 395
 396         /**
 397          * Extract a redirect destination from a string and return the
 398          * Title, or null if the text doesn't contain a valid redirect
 399          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 400          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 401          *
 402          * @param $text String Text with possible redirect
 403          * @return Title
 404          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 405          */
 406         public static function newFromRedirectRecurse( $text ) {
 407                 ContentHandler::deprecated( __METHOD__, '1.21' );
 408
 409                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 410                 return $content->getUltimateRedirectTarget();
 411         }
 412
 413         /**
 414          * Extract a redirect destination from a string and return an
 415          * array of Titles, or null if the text doesn't contain a valid redirect
 416          * The last element in the array is the final destination after all redirects
 417          * have been resolved (up to $wgMaxRedirects times)
 418          *
 419          * @param $text String Text with possible redirect
 420          * @return Array of Titles, with the destination last
 421          * @deprecated since 1.21, use Content::getRedirectChain instead.
 422          */
 423         public static function newFromRedirectArray( $text ) {
 424                 ContentHandler::deprecated( __METHOD__, '1.21' );
 425
 426                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 427                 return $content->getRedirectChain();
 428         }
 429
 430         /**
 431          * Get the prefixed DB key associated with an ID
 432          *
 433          * @param $id Int the page_id of the article
 434          * @return Title an object representing the article, or NULL if no such article was found
 435          */
 436         public static function nameOf( $id ) {
 437                 $dbr = wfGetDB( DB_SLAVE );
 438
 439                 $s = $dbr->selectRow(
 440                         'page',
 441                         array( 'page_namespace', 'page_title' ),
 442                         array( 'page_id' => $id ),
 443                         __METHOD__
 444                 );
 445                 if ( $s === false ) {
 446                         return null;
 447                 }
 448
 449                 $n = self::makeName( $s->page_namespace, $s->page_title );
 450                 return $n;
 451         }
 452
 453         /**
 454          * Get a regex character class describing the legal characters in a link
 455          *
 456          * @return String the list of characters, not delimited
 457          */
 458         public static function legalChars() {
 459                 global $wgLegalTitleChars;
 460                 return $wgLegalTitleChars;
 461         }
 462
 463         /**
 464          * Returns a simple regex that will match on characters and sequences invalid in titles.
 465          * Note that this doesn't pick up many things that could be wrong with titles, but that
 466          * replacing this regex with something valid will make many titles valid.
 467          *
 468          * @return String regex string
 469          */
 470         static function getTitleInvalidRegex() {
 471                 static $rxTc = false;
 472                 if ( !$rxTc ) {
 473                         # Matching titles will be held as illegal.
 474                         $rxTc = '/' .
 475                                 # Any character not allowed is forbidden...
 476                                 '[^' . self::legalChars() . ']' .
 477                                 # URL percent encoding sequences interfere with the ability
 478                                 # to round-trip titles -- you can't link to them consistently.
 479                                 '|%[0-9A-Fa-f]{2}' .
 480                                 # XML/HTML character references produce similar issues.
 481                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 482                                 '|&#[0-9]+;' .
 483                                 '|&#x[0-9A-Fa-f]+;' .
 484                                 '/S';
 485                 }
 486
 487                 return $rxTc;
 488         }
 489
 490         /**
 491          * Get a string representation of a title suitable for
 492          * including in a search index
 493          *
 494          * @param $ns Int a namespace index
 495          * @param $title String text-form main part
 496          * @return String a stripped-down title string ready for the search index
 497          */
 498         public static function indexTitle( $ns, $title ) {
 499                 global $wgContLang;
 500
 501                 $lc = SearchEngine::legalSearchChars() . '&#;';
 502                 $t = $wgContLang->normalizeForSearch( $title );
 503                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 504                 $t = $wgContLang->lc( $t );
 505
 506                 # Handle 's, s'
 507                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 508                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 509
 510                 $t = preg_replace( "/\\s+/", ' ', $t );
 511
 512                 if ( $ns == NS_FILE ) {
 513                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 514                 }
 515                 return trim( $t );
 516         }
 517
 518         /**
 519          * Make a prefixed DB key from a DB key and a namespace index
 520          *
 521          * @param $ns Int numerical representation of the namespace
 522          * @param $title String the DB key form the title
 523          * @param $fragment String The link fragment (after the "#")
 524          * @param $interwiki String The interwiki prefix
 525          * @return String the prefixed form of the title
 526          */
 527         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 528                 global $wgContLang;
 529
 530                 $namespace = $wgContLang->getNsText( $ns );
 531                 $name = $namespace == '' ? $title : "$namespace:$title";
 532                 if ( strval( $interwiki ) != '' ) {
 533                         $name = "$interwiki:$name";
 534                 }
 535                 if ( strval( $fragment ) != '' ) {
 536                         $name .= '#' . $fragment;
 537                 }
 538                 return $name;
 539         }
 540
 541         /**
 542          * Escape a text fragment, say from a link, for a URL
 543          *
 544          * @param $fragment string containing a URL or link fragment (after the "#")
 545          * @return String: escaped string
 546          */
 547         static function escapeFragmentForURL( $fragment ) {
 548                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 549                 # fragments appear not to work in IE (at least up to 7) or in at least
 550                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 551                 # to care if they aren't encoded.
 552                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 553         }
 554
 555         /**
 556          * Callback for usort() to do title sorts by (namespace, title)
 557          *
 558          * @param $a Title
 559          * @param $b Title
 560          *
 561          * @return Integer: result of string comparison, or namespace comparison
 562          */
 563         public static function compare( $a, $b ) {
 564                 if ( $a->getNamespace() == $b->getNamespace() ) {
 565                         return strcmp( $a->getText(), $b->getText() );
 566                 } else {
 567                         return $a->getNamespace() - $b->getNamespace();
 568                 }
 569         }
 570
 571         /**
 572          * Determine whether the object refers to a page within
 573          * this project.
 574          *
 575          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 576          */
 577         public function isLocal() {
 578                 if ( $this->mInterwiki != '' ) {
 579                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 580                 } else {
 581                         return true;
 582                 }
 583         }
 584
 585         /**
 586          * Is this Title interwiki?
 587          *
 588          * @return Bool
 589          */
 590         public function isExternal() {
 591                 return ( $this->mInterwiki != '' );
 592         }
 593
 594         /**
 595          * Get the interwiki prefix (or null string)
 596          *
 597          * @return String Interwiki prefix
 598          */
 599         public function getInterwiki() {
 600                 return $this->mInterwiki;
 601         }
 602
 603         /**
 604          * Determine whether the object refers to a page within
 605          * this project and is transcludable.
 606          *
 607          * @return Bool TRUE if this is transcludable
 608          */
 609         public function isTrans() {
 610                 if ( $this->mInterwiki == '' ) {
 611                         return false;
 612                 }
 613
 614                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 615         }
 616
 617         /**
 618          * Returns the DB name of the distant wiki which owns the object.
 619          *
 620          * @return String the DB name
 621          */
 622         public function getTransWikiID() {
 623                 if ( $this->mInterwiki == '' ) {
 624                         return false;
 625                 }
 626
 627                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 628         }
 629
 630         /**
 631          * Get the text form (spaces not underscores) of the main part
 632          *
 633          * @return String Main part of the title
 634          */
 635         public function getText() {
 636                 return $this->mTextform;
 637         }
 638
 639         /**
 640          * Get the URL-encoded form of the main part
 641          *
 642          * @return String Main part of the title, URL-encoded
 643          */
 644         public function getPartialURL() {
 645                 return $this->mUrlform;
 646         }
 647
 648         /**
 649          * Get the main part with underscores
 650          *
 651          * @return String: Main part of the title, with underscores
 652          */
 653         public function getDBkey() {
 654                 return $this->mDbkeyform;
 655         }
 656
 657         /**
 658          * Get the DB key with the initial letter case as specified by the user
 659          *
 660          * @return String DB key
 661          */
 662         function getUserCaseDBKey() {
 663                 return $this->mUserCaseDBKey;
 664         }
 665
 666         /**
 667          * Get the namespace index, i.e. one of the NS_xxxx constants.
 668          *
 669          * @return Integer: Namespace index
 670          */
 671         public function getNamespace() {
 672                 return $this->mNamespace;
 673         }
 674
 675         /**
 676          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 677          *
 678          * @return String: Content model id
 679          */
 680         public function getContentModel() {
 681                 if ( !$this->mContentModel ) {
 682                         $linkCache = LinkCache::singleton();
 683                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 684                 }
 685
 686                 if ( !$this->mContentModel ) {
 687                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 688                 }
 689
 690                 if( !$this->mContentModel ) {
 691                         throw new MWException( "failed to determin content model!" );
 692                 }
 693
 694                 return $this->mContentModel;
 695         }
 696
 697         /**
 698          * Convenience method for checking a title's content model name
 699          *
 700          * @param String $id The content model ID (use the CONTENT_MODEL_XXX constants).
 701          * @return Boolean true if $this->getContentModel() == $id
 702          */
 703         public function hasContentModel( $id ) {
 704                 return $this->getContentModel() == $id;
 705         }
 706
 707         /**
 708          * Get the namespace text
 709          *
 710          * @return String: Namespace text
 711          */
 712         public function getNsText() {
 713                 global $wgContLang;
 714
 715                 if ( $this->mInterwiki != '' ) {
 716                         // This probably shouldn't even happen. ohh man, oh yuck.
 717                         // But for interwiki transclusion it sometimes does.
 718                         // Shit. Shit shit shit.
 719                         //
 720                         // Use the canonical namespaces if possible to try to
 721                         // resolve a foreign namespace.
 722                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 723                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 724                         }
 725                 }
 726
 727                 if ( $wgContLang->needsGenderDistinction() &&
 728                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 729                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 730                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 731                 }
 732
 733                 return $wgContLang->getNsText( $this->mNamespace );
 734         }
 735
 736         /**
 737          * Get the namespace text of the subject (rather than talk) page
 738          *
 739          * @return String Namespace text
 740          */
 741         public function getSubjectNsText() {
 742                 global $wgContLang;
 743                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 744         }
 745
 746         /**
 747          * Get the namespace text of the talk page
 748          *
 749          * @return String Namespace text
 750          */
 751         public function getTalkNsText() {
 752                 global $wgContLang;
 753                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 754         }
 755
 756         /**
 757          * Could this title have a corresponding talk page?
 758          *
 759          * @return Bool TRUE or FALSE
 760          */
 761         public function canTalk() {
 762                 return( MWNamespace::canTalk( $this->mNamespace ) );
 763         }
 764
 765         /**
 766          * Is this in a namespace that allows actual pages?
 767          *
 768          * @return Bool
 769          * @internal note -- uses hardcoded namespace index instead of constants
 770          */
 771         public function canExist() {
 772                 return $this->mNamespace >= NS_MAIN;
 773         }
 774
 775         /**
 776          * Can this title be added to a user's watchlist?
 777          *
 778          * @return Bool TRUE or FALSE
 779          */
 780         public function isWatchable() {
 781                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 782         }
 783
 784         /**
 785          * Returns true if this is a special page.
 786          *
 787          * @return boolean
 788          */
 789         public function isSpecialPage() {
 790                 return $this->getNamespace() == NS_SPECIAL;
 791         }
 792
 793         /**
 794          * Returns true if this title resolves to the named special page
 795          *
 796          * @param $name String The special page name
 797          * @return boolean
 798          */
 799         public function isSpecial( $name ) {
 800                 if ( $this->isSpecialPage() ) {
 801                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 802                         if ( $name == $thisName ) {
 803                                 return true;
 804                         }
 805                 }
 806                 return false;
 807         }
 808
 809         /**
 810          * If the Title refers to a special page alias which is not the local default, resolve
 811          * the alias, and localise the name as necessary.  Otherwise, return $this
 812          *
 813          * @return Title
 814          */
 815         public function fixSpecialName() {
 816                 if ( $this->isSpecialPage() ) {
 817                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 818                         if ( $canonicalName ) {
 819                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 820                                 if ( $localName != $this->mDbkeyform ) {
 821                                         return Title::makeTitle( NS_SPECIAL, $localName );
 822                                 }
 823                         }
 824                 }
 825                 return $this;
 826         }
 827
 828         /**
 829          * Returns true if the title is inside the specified namespace.
 830          *
 831          * Please make use of this instead of comparing to getNamespace()
 832          * This function is much more resistant to changes we may make
 833          * to namespaces than code that makes direct comparisons.
 834          * @param $ns int The namespace
 835          * @return bool
 836          * @since 1.19
 837          */
 838         public function inNamespace( $ns ) {
 839                 return MWNamespace::equals( $this->getNamespace(), $ns );
 840         }
 841
 842         /**
 843          * Returns true if the title is inside one of the specified namespaces.
 844          *
 845          * @param ...$namespaces The namespaces to check for
 846          * @return bool
 847          * @since 1.19
 848          */
 849         public function inNamespaces( /* ... */ ) {
 850                 $namespaces = func_get_args();
 851                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 852                         $namespaces = $namespaces[0];
 853                 }
 854
 855                 foreach ( $namespaces as $ns ) {
 856                         if ( $this->inNamespace( $ns ) ) {
 857                                 return true;
 858                         }
 859                 }
 860
 861                 return false;
 862         }
 863
 864         /**
 865          * Returns true if the title has the same subject namespace as the
 866          * namespace specified.
 867          * For example this method will take NS_USER and return true if namespace
 868          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 869          * as their subject namespace.
 870          *
 871          * This is MUCH simpler than individually testing for equivilance
 872          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 873          * @since 1.19
 874          * @param $ns int
 875          * @return bool
 876          */
 877         public function hasSubjectNamespace( $ns ) {
 878                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 879         }
 880
 881         /**
 882          * Is this Title in a namespace which contains content?
 883          * In other words, is this a content page, for the purposes of calculating
 884          * statistics, etc?
 885          *
 886          * @return Boolean
 887          */
 888         public function isContentPage() {
 889                 return MWNamespace::isContent( $this->getNamespace() );
 890         }
 891
 892         /**
 893          * Would anybody with sufficient privileges be able to move this page?
 894          * Some pages just aren't movable.
 895          *
 896          * @return Bool TRUE or FALSE
 897          */
 898         public function isMovable() {
 899                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 900                         // Interwiki title or immovable namespace. Hooks don't get to override here
 901                         return false;
 902                 }
 903
 904                 $result = true;
 905                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 906                 return $result;
 907         }
 908
 909         /**
 910          * Is this the mainpage?
 911          * @note Title::newFromText seams to be sufficiently optimized by the title
 912          * cache that we don't need to over-optimize by doing direct comparisons and
 913          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 914          * ends up reporting something differently than $title->isMainPage();
 915          *
 916          * @since 1.18
 917          * @return Bool
 918          */
 919         public function isMainPage() {
 920                 return $this->equals( Title::newMainPage() );
 921         }
 922
 923         /**
 924          * Is this a subpage?
 925          *
 926          * @return Bool
 927          */
 928         public function isSubpage() {
 929                 return MWNamespace::hasSubpages( $this->mNamespace )
 930                         ? strpos( $this->getText(), '/' ) !== false
 931                         : false;
 932         }
 933
 934         /**
 935          * Is this a conversion table for the LanguageConverter?
 936          *
 937          * @return Bool
 938          */
 939         public function isConversionTable() {
 940                 //@todo: ConversionTable should become a separate content model.
 941
 942                 return $this->getNamespace() == NS_MEDIAWIKI &&
 943                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 944         }
 945
 946         /**
 947          * Does that page contain wikitext, or it is JS, CSS or whatever?
 948          *
 949          * @return Bool
 950          */
 951         public function isWikitextPage() {
 952                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 953         }
 954
 955         /**
 956          * Could this page contain custom CSS or JavaScript for the global UI.
 957          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 958          * or CONTENT_MODEL_JAVASCRIPT.
 959          *
 960          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 961          *
 962          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 963          *
 964          * @return Bool
 965          */
 966         public function isCssOrJsPage() {
 967                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 968                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 969                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 970
 971                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 972                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 973
 974                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 975
 976                 return $isCssOrJsPage;
 977         }
 978
 979         /**
 980          * Is this a .css or .js subpage of a user page?
 981          * @return Bool
 982          */
 983         public function isCssJsSubpage() {
 984                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 985                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 986                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 987         }
 988
 989         /**
 990          * Trim down a .css or .js subpage title to get the corresponding skin name
 991          *
 992          * @return string containing skin name from .css or .js subpage title
 993          */
 994         public function getSkinFromCssJsSubpage() {
 995                 $subpage = explode( '/', $this->mTextform );
 996                 $subpage = $subpage[ count( $subpage ) - 1 ];
 997                 $lastdot = strrpos( $subpage, '.' );
 998                 if ( $lastdot === false )
 999                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1000                 return substr( $subpage, 0, $lastdot );
1001         }
1002
1003         /**
1004          * Is this a .css subpage of a user page?
1005          *
1006          * @return Bool
1007          */
1008         public function isCssSubpage() {
1009                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1010                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1011         }
1012
1013         /**
1014          * Is this a .js subpage of a user page?
1015          *
1016          * @return Bool
1017          */
1018         public function isJsSubpage() {
1019                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1020                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1021         }
1022
1023         /**
1024          * Is this a talk page of some sort?
1025          *
1026          * @return Bool
1027          */
1028         public function isTalkPage() {
1029                 return MWNamespace::isTalk( $this->getNamespace() );
1030         }
1031
1032         /**
1033          * Get a Title object associated with the talk page of this article
1034          *
1035          * @return Title the object for the talk page
1036          */
1037         public function getTalkPage() {
1038                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1039         }
1040
1041         /**
1042          * Get a title object associated with the subject page of this
1043          * talk page
1044          *
1045          * @return Title the object for the subject page
1046          */
1047         public function getSubjectPage() {
1048                 // Is this the same title?
1049                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1050                 if ( $this->getNamespace() == $subjectNS ) {
1051                         return $this;
1052                 }
1053                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1054         }
1055
1056         /**
1057          * Get the default namespace index, for when there is no namespace
1058          *
1059          * @return Int Default namespace index
1060          */
1061         public function getDefaultNamespace() {
1062                 return $this->mDefaultNamespace;
1063         }
1064
1065         /**
1066          * Get title for search index
1067          *
1068          * @return String a stripped-down title string ready for the
1069          *  search index
1070          */
1071         public function getIndexTitle() {
1072                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1073         }
1074
1075         /**
1076          * Get the Title fragment (i.e.\ the bit after the #) in text form
1077          *
1078          * @return String Title fragment
1079          */
1080         public function getFragment() {
1081                 return $this->mFragment;
1082         }
1083
1084         /**
1085          * Get the fragment in URL form, including the "#" character if there is one
1086          * @return String Fragment in URL form
1087          */
1088         public function getFragmentForURL() {
1089                 if ( $this->mFragment == '' ) {
1090                         return '';
1091                 } else {
1092                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1093                 }
1094         }
1095
1096         /**
1097          * Set the fragment for this title. Removes the first character from the
1098          * specified fragment before setting, so it assumes you're passing it with
1099          * an initial "#".
1100          *
1101          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1102          * Still in active use privately.
1103          *
1104          * @param $fragment String text
1105          */
1106         public function setFragment( $fragment ) {
1107                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1108         }
1109
1110         /**
1111          * Prefix some arbitrary text with the namespace or interwiki prefix
1112          * of this object
1113          *
1114          * @param $name String the text
1115          * @return String the prefixed text
1116          * @private
1117          */
1118         private function prefix( $name ) {
1119                 $p = '';
1120                 if ( $this->mInterwiki != '' ) {
1121                         $p = $this->mInterwiki . ':';
1122                 }
1123
1124                 if ( 0 != $this->mNamespace ) {
1125                         $p .= $this->getNsText() . ':';
1126                 }
1127                 return $p . $name;
1128         }
1129
1130         /**
1131          * Get the prefixed database key form
1132          *
1133          * @return String the prefixed title, with underscores and
1134          *  any interwiki and namespace prefixes
1135          */
1136         public function getPrefixedDBkey() {
1137                 $s = $this->prefix( $this->mDbkeyform );
1138                 $s = str_replace( ' ', '_', $s );
1139                 return $s;
1140         }
1141
1142         /**
1143          * Get the prefixed title with spaces.
1144          * This is the form usually used for display
1145          *
1146          * @return String the prefixed title, with spaces
1147          */
1148         public function getPrefixedText() {
1149                 // @todo FIXME: Bad usage of empty() ?
1150                 if ( empty( $this->mPrefixedText ) ) {
1151                         $s = $this->prefix( $this->mTextform );
1152                         $s = str_replace( '_', ' ', $s );
1153                         $this->mPrefixedText = $s;
1154                 }
1155                 return $this->mPrefixedText;
1156         }
1157
1158         /**
1159          * Return a string representation of this title
1160          *
1161          * @return String representation of this title
1162          */
1163         public function __toString() {
1164                 return $this->getPrefixedText();
1165         }
1166
1167         /**
1168          * Get the prefixed title with spaces, plus any fragment
1169          * (part beginning with '#')
1170          *
1171          * @return String the prefixed title, with spaces and the fragment, including '#'
1172          */
1173         public function getFullText() {
1174                 $text = $this->getPrefixedText();
1175                 if ( $this->mFragment != '' ) {
1176                         $text .= '#' . $this->mFragment;
1177                 }
1178                 return $text;
1179         }
1180
1181         /**
1182          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1183          *
1184          * @par Example:
1185          * @code
1186          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1187          * # returns: 'Foo'
1188          * @endcode
1189          *
1190          * @return String Root name
1191          * @since 1.20
1192          */
1193         public function getRootText() {
1194                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1195                         return $this->getText();
1196                 }
1197
1198                 return strtok( $this->getText(), '/' );
1199         }
1200
1201         /**
1202          * Get the root page name title, i.e. the leftmost part before any slashes
1203          *
1204          * @par Example:
1205          * @code
1206          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1207          * # returns: Title{User:Foo}
1208          * @endcode
1209          *
1210          * @return Title Root title
1211          * @since 1.20
1212          */
1213         public function getRootTitle() {
1214                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1215         }
1216
1217         /**
1218          * Get the base page name without a namespace, i.e. the part before the subpage name
1219          *
1220          * @par Example:
1221          * @code
1222          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1223          * # returns: 'Foo/Bar'
1224          * @endcode
1225          *
1226          * @return String Base name
1227          */
1228         public function getBaseText() {
1229                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1230                         return $this->getText();
1231                 }
1232
1233                 $parts = explode( '/', $this->getText() );
1234                 # Don't discard the real title if there's no subpage involved
1235                 if ( count( $parts ) > 1 ) {
1236                         unset( $parts[count( $parts ) - 1] );
1237                 }
1238                 return implode( '/', $parts );
1239         }
1240
1241         /**
1242          * Get the base page name title, i.e. the part before the subpage name
1243          *
1244          * @par Example:
1245          * @code
1246          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1247          * # returns: Title{User:Foo/Bar}
1248          * @endcode
1249          *
1250          * @return Title Base title
1251          * @since 1.20
1252          */
1253         public function getBaseTitle() {
1254                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1255         }
1256
1257         /**
1258          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1259          *
1260          * @par Example:
1261          * @code
1262          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1263          * # returns: "Baz"
1264          * @endcode
1265          *
1266          * @return String Subpage name
1267          */
1268         public function getSubpageText() {
1269                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1270                         return( $this->mTextform );
1271                 }
1272                 $parts = explode( '/', $this->mTextform );
1273                 return( $parts[count( $parts ) - 1] );
1274         }
1275
1276         /**
1277          * Get the title for a subpage of the current page
1278          *
1279          * @par Example:
1280          * @code
1281          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1282          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1283          * @endcode
1284          *
1285          * @param $text String The subpage name to add to the title
1286          * @return Title Subpage title
1287          * @since 1.20
1288          */
1289         public function getSubpage( $text ) {
1290                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1291         }
1292
1293         /**
1294          * Get the HTML-escaped displayable text form.
1295          * Used for the title field in <a> tags.
1296          *
1297          * @return String the text, including any prefixes
1298          */
1299         public function getEscapedText() {
1300                 wfDeprecated( __METHOD__, '1.19' );
1301                 return htmlspecialchars( $this->getPrefixedText() );
1302         }
1303
1304         /**
1305          * Get a URL-encoded form of the subpage text
1306          *
1307          * @return String URL-encoded subpage name
1308          */
1309         public function getSubpageUrlForm() {
1310                 $text = $this->getSubpageText();
1311                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1312                 return( $text );
1313         }
1314
1315         /**
1316          * Get a URL-encoded title (not an actual URL) including interwiki
1317          *
1318          * @return String the URL-encoded form
1319          */
1320         public function getPrefixedURL() {
1321                 $s = $this->prefix( $this->mDbkeyform );
1322                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1323                 return $s;
1324         }
1325
1326         /**
1327          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1328          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1329          * second argument named variant. This was deprecated in favor
1330          * of passing an array of option with a "variant" key
1331          * Once $query2 is removed for good, this helper can be dropped
1332          * andthe wfArrayToCGI moved to getLocalURL();
1333          *
1334          * @since 1.19 (r105919)
1335          * @param $query
1336          * @param $query2 bool
1337          * @return String
1338          */
1339         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1340                 if( $query2 !== false ) {
1341                         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" );
1342                 }
1343                 if ( is_array( $query ) ) {
1344                         $query = wfArrayToCGI( $query );
1345                 }
1346                 if ( $query2 ) {
1347                         if ( is_string( $query2 ) ) {
1348                                 // $query2 is a string, we will consider this to be
1349                                 // a deprecated $variant argument and add it to the query
1350                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1351                         } else {
1352                                 $query2 = wfArrayToCGI( $query2 );
1353                         }
1354                         // If we have $query content add a & to it first
1355                         if ( $query ) {
1356                                 $query .= '&';
1357                         }
1358                         // Now append the queries together
1359                         $query .= $query2;
1360                 }
1361                 return $query;
1362         }
1363
1364         /**
1365          * Get a real URL referring to this title, with interwiki link and
1366          * fragment
1367          *
1368          * See getLocalURL for the arguments.
1369          *
1370          * @see self::getLocalURL
1371          * @see wfExpandUrl
1372          * @param $query
1373          * @param $query2 bool
1374          * @param $proto Protocol type to use in URL
1375          * @return String the URL
1376          */
1377         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1378                 $query = self::fixUrlQueryArgs( $query, $query2 );
1379
1380                 # Hand off all the decisions on urls to getLocalURL
1381                 $url = $this->getLocalURL( $query );
1382
1383                 # Expand the url to make it a full url. Note that getLocalURL has the
1384                 # potential to output full urls for a variety of reasons, so we use
1385                 # wfExpandUrl instead of simply prepending $wgServer
1386                 $url = wfExpandUrl( $url, $proto );
1387
1388                 # Finally, add the fragment.
1389                 $url .= $this->getFragmentForURL();
1390
1391                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1392                 return $url;
1393         }
1394
1395         /**
1396          * Get a URL with no fragment or server name.  If this page is generated
1397          * with action=render, $wgServer is prepended.
1398          *
1399
1400          * @param $query string|array an optional query string,
1401          *   not used for interwiki     links. Can be specified as an associative array as well,
1402          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1403          *   Some query patterns will trigger various shorturl path replacements.
1404          * @param $query2 Mixed: An optional secondary query array. This one MUST
1405          *   be an array. If a string is passed it will be interpreted as a deprecated
1406          *   variant argument and urlencoded into a variant= argument.
1407          *   This second query argument will be added to the $query
1408          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1409          *   pair in the first parameter array instead.
1410          *
1411          * @return String the URL
1412          */
1413         public function getLocalURL( $query = '', $query2 = false ) {
1414                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1415
1416                 $query = self::fixUrlQueryArgs( $query, $query2 );
1417
1418                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1419                 if ( $interwiki ) {
1420                         $namespace = $this->getNsText();
1421                         if ( $namespace != '' ) {
1422                                 # Can this actually happen? Interwikis shouldn't be parsed.
1423                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1424                                 $namespace .= ':';
1425                         }
1426                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1427                         $url = wfAppendQuery( $url, $query );
1428                 } else {
1429                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1430                         if ( $query == '' ) {
1431                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1432                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1433                         } else {
1434                                 global $wgVariantArticlePath, $wgActionPaths;
1435                                 $url = false;
1436                                 $matches = array();
1437
1438                                 if ( !empty( $wgActionPaths ) &&
1439                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1440                                 {
1441                                         $action = urldecode( $matches[2] );
1442                                         if ( isset( $wgActionPaths[$action] ) ) {
1443                                                 $query = $matches[1];
1444                                                 if ( isset( $matches[4] ) ) {
1445                                                         $query .= $matches[4];
1446                                                 }
1447                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1448                                                 if ( $query != '' ) {
1449                                                         $url = wfAppendQuery( $url, $query );
1450                                                 }
1451                                         }
1452                                 }
1453
1454                                 if ( $url === false &&
1455                                         $wgVariantArticlePath &&
1456                                         $this->getPageLanguage()->hasVariants() &&
1457                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1458                                 {
1459                                         $variant = urldecode( $matches[1] );
1460                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1461                                                 // Only do the variant replacement if the given variant is a valid
1462                                                 // variant for the page's language.
1463                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1464                                                 $url = str_replace( '$1', $dbkey, $url );
1465                                         }
1466                                 }
1467
1468                                 if ( $url === false ) {
1469                                         if ( $query == '-' ) {
1470                                                 $query = '';
1471                                         }
1472                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1473                                 }
1474                         }
1475
1476                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1477
1478                         // @todo FIXME: This causes breakage in various places when we
1479                         // actually expected a local URL and end up with dupe prefixes.
1480                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1481                                 $url = $wgServer . $url;
1482                         }
1483                 }
1484                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1485                 return $url;
1486         }
1487
1488         /**
1489          * Get a URL that's the simplest URL that will be valid to link, locally,
1490          * to the current Title.  It includes the fragment, but does not include
1491          * the server unless action=render is used (or the link is external).  If
1492          * there's a fragment but the prefixed text is empty, we just return a link
1493          * to the fragment.
1494          *
1495          * The result obviously should not be URL-escaped, but does need to be
1496          * HTML-escaped if it's being output in HTML.
1497          *
1498          * See getLocalURL for the arguments.
1499          *
1500          * @param $query
1501          * @param $query2 bool
1502          * @param $proto Protocol to use; setting this will cause a full URL to be used
1503          * @see self::getLocalURL
1504          * @return String the URL
1505          */
1506         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1507                 wfProfileIn( __METHOD__ );
1508                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1509                         $ret = $this->getFullURL( $query, $query2, $proto );
1510                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1511                         $ret = $this->getFragmentForURL();
1512                 } else {
1513                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1514                 }
1515                 wfProfileOut( __METHOD__ );
1516                 return $ret;
1517         }
1518
1519         /**
1520          * Get an HTML-escaped version of the URL form, suitable for
1521          * using in a link, without a server name or fragment
1522          *
1523          * See getLocalURL for the arguments.
1524          *
1525          * @see self::getLocalURL
1526          * @param $query string
1527          * @param $query2 bool|string
1528          * @return String the URL
1529          */
1530         public function escapeLocalURL( $query = '', $query2 = false ) {
1531                 wfDeprecated( __METHOD__, '1.19' );
1532                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1533         }
1534
1535         /**
1536          * Get an HTML-escaped version of the URL form, suitable for
1537          * using in a link, including the server name and fragment
1538          *
1539          * See getLocalURL for the arguments.
1540          *
1541          * @see self::getLocalURL
1542          * @return String the URL
1543          */
1544         public function escapeFullURL( $query = '', $query2 = false ) {
1545                 wfDeprecated( __METHOD__, '1.19' );
1546                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1547         }
1548
1549         /**
1550          * Get the URL form for an internal link.
1551          * - Used in various Squid-related code, in case we have a different
1552          * internal hostname for the server from the exposed one.
1553          *
1554          * This uses $wgInternalServer to qualify the path, or $wgServer
1555          * if $wgInternalServer is not set. If the server variable used is
1556          * protocol-relative, the URL will be expanded to http://
1557          *
1558          * See getLocalURL for the arguments.
1559          *
1560          * @see self::getLocalURL
1561          * @return String the URL
1562          */
1563         public function getInternalURL( $query = '', $query2 = false ) {
1564                 global $wgInternalServer, $wgServer;
1565                 $query = self::fixUrlQueryArgs( $query, $query2 );
1566                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1567                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1568                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1569                 return $url;
1570         }
1571
1572         /**
1573          * Get the URL for a canonical link, for use in things like IRC and
1574          * e-mail notifications. Uses $wgCanonicalServer and the
1575          * GetCanonicalURL hook.
1576          *
1577          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1578          *
1579          * See getLocalURL for the arguments.
1580          *
1581          * @see self::getLocalURL
1582          * @return string The URL
1583          * @since 1.18
1584          */
1585         public function getCanonicalURL( $query = '', $query2 = false ) {
1586                 $query = self::fixUrlQueryArgs( $query, $query2 );
1587                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1588                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1589                 return $url;
1590         }
1591
1592         /**
1593          * HTML-escaped version of getCanonicalURL()
1594          *
1595          * See getLocalURL for the arguments.
1596          *
1597          * @see self::getLocalURL
1598          * @since 1.18
1599          * @return string
1600          */
1601         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1602                 wfDeprecated( __METHOD__, '1.19' );
1603                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1604         }
1605
1606         /**
1607          * Get the edit URL for this Title
1608          *
1609          * @return String the URL, or a null string if this is an
1610          *  interwiki link
1611          */
1612         public function getEditURL() {
1613                 if ( $this->mInterwiki != '' ) {
1614                         return '';
1615                 }
1616                 $s = $this->getLocalURL( 'action=edit' );
1617
1618                 return $s;
1619         }
1620
1621         /**
1622          * Is $wgUser watching this page?
1623          *
1624          * @deprecated in 1.20; use User::isWatched() instead.
1625          * @return Bool
1626          */
1627         public function userIsWatching() {
1628                 global $wgUser;
1629
1630                 if ( is_null( $this->mWatched ) ) {
1631                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1632                                 $this->mWatched = false;
1633                         } else {
1634                                 $this->mWatched = $wgUser->isWatched( $this );
1635                         }
1636                 }
1637                 return $this->mWatched;
1638         }
1639
1640         /**
1641          * Can $wgUser read this page?
1642          *
1643          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1644          * @return Bool
1645          * @todo fold these checks into userCan()
1646          */
1647         public function userCanRead() {
1648                 wfDeprecated( __METHOD__, '1.19' );
1649                 return $this->userCan( 'read' );
1650         }
1651
1652         /**
1653          * Can $user perform $action on this page?
1654          * This skips potentially expensive cascading permission checks
1655          * as well as avoids expensive error formatting
1656          *
1657          * Suitable for use for nonessential UI controls in common cases, but
1658          * _not_ for functional access control.
1659          *
1660          * May provide false positives, but should never provide a false negative.
1661          *
1662          * @param $action String action that permission needs to be checked for
1663          * @param $user User to check (since 1.19); $wgUser will be used if not
1664          *              provided.
1665          * @return Bool
1666          */
1667         public function quickUserCan( $action, $user = null ) {
1668                 return $this->userCan( $action, $user, false );
1669         }
1670
1671         /**
1672          * Can $user perform $action on this page?
1673          *
1674          * @param $action String action that permission needs to be checked for
1675          * @param $user User to check (since 1.19); $wgUser will be used if not
1676          *   provided.
1677          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1678          *   unnecessary queries.
1679          * @return Bool
1680          */
1681         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1682                 if ( !$user instanceof User ) {
1683                         global $wgUser;
1684                         $user = $wgUser;
1685                 }
1686                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1687         }
1688
1689         /**
1690          * Can $user perform $action on this page?
1691          *
1692          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1693          *
1694          * @param $action String action that permission needs to be checked for
1695          * @param $user User to check
1696          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1697          *   queries by skipping checks for cascading protections and user blocks.
1698          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1699          *   whose corresponding errors may be ignored.
1700          * @return Array of arguments to wfMessage to explain permissions problems.
1701          */
1702         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1703                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1704
1705                 // Remove the errors being ignored.
1706                 foreach ( $errors as $index => $error ) {
1707                         $error_key = is_array( $error ) ? $error[0] : $error;
1708
1709                         if ( in_array( $error_key, $ignoreErrors ) ) {
1710                                 unset( $errors[$index] );
1711                         }
1712                 }
1713
1714                 return $errors;
1715         }
1716
1717         /**
1718          * Permissions checks that fail most often, and which are easiest to test.
1719          *
1720          * @param $action String the action to check
1721          * @param $user User user to check
1722          * @param $errors Array list of current errors
1723          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1724          * @param $short Boolean short circuit on first error
1725          *
1726          * @return Array list of errors
1727          */
1728         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1729                 if ( $action == 'create' ) {
1730                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1731                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1732                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1733                         }
1734                 } elseif ( $action == 'move' ) {
1735                         if ( !$user->isAllowed( 'move-rootuserpages' )
1736                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1737                                 // Show user page-specific message only if the user can move other pages
1738                                 $errors[] = array( 'cant-move-user-page' );
1739                         }
1740
1741                         // Check if user is allowed to move files if it's a file
1742                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1743                                 $errors[] = array( 'movenotallowedfile' );
1744                         }
1745
1746                         if ( !$user->isAllowed( 'move' ) ) {
1747                                 // User can't move anything
1748                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1749                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1750                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1751                                         // custom message if logged-in users without any special rights can move
1752                                         $errors[] = array( 'movenologintext' );
1753                                 } else {
1754                                         $errors[] = array( 'movenotallowed' );
1755                                 }
1756                         }
1757                 } elseif ( $action == 'move-target' ) {
1758                         if ( !$user->isAllowed( 'move' ) ) {
1759                                 // User can't move anything
1760                                 $errors[] = array( 'movenotallowed' );
1761                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1762                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1763                                 // Show user page-specific message only if the user can move other pages
1764                                 $errors[] = array( 'cant-move-to-user-page' );
1765                         }
1766                 } elseif ( !$user->isAllowed( $action ) ) {
1767                         $errors[] = $this->missingPermissionError( $action, $short );
1768                 }
1769
1770                 return $errors;
1771         }
1772
1773         /**
1774          * Add the resulting error code to the errors array
1775          *
1776          * @param $errors Array list of current errors
1777          * @param $result Mixed result of errors
1778          *
1779          * @return Array list of errors
1780          */
1781         private function resultToError( $errors, $result ) {
1782                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1783                         // A single array representing an error
1784                         $errors[] = $result;
1785                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1786                         // A nested array representing multiple errors
1787                         $errors = array_merge( $errors, $result );
1788                 } elseif ( $result !== '' && is_string( $result ) ) {
1789                         // A string representing a message-id
1790                         $errors[] = array( $result );
1791                 } elseif ( $result === false ) {
1792                         // a generic "We don't want them to do that"
1793                         $errors[] = array( 'badaccess-group0' );
1794                 }
1795                 return $errors;
1796         }
1797
1798         /**
1799          * Check various permission hooks
1800          *
1801          * @param $action String the action to check
1802          * @param $user User user to check
1803          * @param $errors Array list of current errors
1804          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1805          * @param $short Boolean short circuit on first error
1806          *
1807          * @return Array list of errors
1808          */
1809         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1810                 // Use getUserPermissionsErrors instead
1811                 $result = '';
1812                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1813                         return $result ? array() : array( array( 'badaccess-group0' ) );
1814                 }
1815                 // Check getUserPermissionsErrors hook
1816                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1817                         $errors = $this->resultToError( $errors, $result );
1818                 }
1819                 // Check getUserPermissionsErrorsExpensive hook
1820                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1821                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1822                         $errors = $this->resultToError( $errors, $result );
1823                 }
1824
1825                 return $errors;
1826         }
1827
1828         /**
1829          * Check permissions on special pages & namespaces
1830          *
1831          * @param $action String the action to check
1832          * @param $user User user to check
1833          * @param $errors Array list of current errors
1834          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1835          * @param $short Boolean short circuit on first error
1836          *
1837          * @return Array list of errors
1838          */
1839         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1840                 # Only 'createaccount' and 'execute' can be performed on
1841                 # special pages, which don't actually exist in the DB.
1842                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1843                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1844                         $errors[] = array( 'ns-specialprotected' );
1845                 }
1846
1847                 # Check $wgNamespaceProtection for restricted namespaces
1848                 if ( $this->isNamespaceProtected( $user ) ) {
1849                         $ns = $this->mNamespace == NS_MAIN ?
1850                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1851                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1852                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1853                 }
1854
1855                 return $errors;
1856         }
1857
1858         /**
1859          * Check CSS/JS sub-page permissions
1860          *
1861          * @param $action String the action to check
1862          * @param $user User user to check
1863          * @param $errors Array list of current errors
1864          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1865          * @param $short Boolean short circuit on first error
1866          *
1867          * @return Array list of errors
1868          */
1869         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1870                 # Protect css/js subpages of user pages
1871                 # XXX: this might be better using restrictions
1872                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1873                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1874                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1875                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1876                                 $errors[] = array( 'customcssprotected' );
1877                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1878                                 $errors[] = array( 'customjsprotected' );
1879                         }
1880                 }
1881
1882                 return $errors;
1883         }
1884
1885         /**
1886          * Check against page_restrictions table requirements on this
1887          * page. The user must possess all required rights for this
1888          * action.
1889          *
1890          * @param $action String the action to check
1891          * @param $user User user to check
1892          * @param $errors Array list of current errors
1893          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1894          * @param $short Boolean short circuit on first error
1895          *
1896          * @return Array list of errors
1897          */
1898         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1899                 foreach ( $this->getRestrictions( $action ) as $right ) {
1900                         // Backwards compatibility, rewrite sysop -> protect
1901                         if ( $right == 'sysop' ) {
1902                                 $right = 'protect';
1903                         }
1904                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1905                                 // Users with 'editprotected' permission can edit protected pages
1906                                 // without cascading option turned on.
1907                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1908                                         || $this->mCascadeRestriction )
1909                                 {
1910                                         $errors[] = array( 'protectedpagetext', $right );
1911                                 }
1912                         }
1913                 }
1914
1915                 return $errors;
1916         }
1917
1918         /**
1919          * Check restrictions on cascading pages.
1920          *
1921          * @param $action String the action to check
1922          * @param $user User to check
1923          * @param $errors Array list of current errors
1924          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1925          * @param $short Boolean short circuit on first error
1926          *
1927          * @return Array list of errors
1928          */
1929         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1930                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1931                         # We /could/ use the protection level on the source page, but it's
1932                         # fairly ugly as we have to establish a precedence hierarchy for pages
1933                         # included by multiple cascade-protected pages. So just restrict
1934                         # it to people with 'protect' permission, as they could remove the
1935                         # protection anyway.
1936                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1937                         # Cascading protection depends on more than this page...
1938                         # Several cascading protected pages may include this page...
1939                         # Check each cascading level
1940                         # This is only for protection restrictions, not for all actions
1941                         if ( isset( $restrictions[$action] ) ) {
1942                                 foreach ( $restrictions[$action] as $right ) {
1943                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1944                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1945                                                 $pages = '';
1946                                                 foreach ( $cascadingSources as $page )
1947                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1948                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1949                                         }
1950                                 }
1951                         }
1952                 }
1953
1954                 return $errors;
1955         }
1956
1957         /**
1958          * Check action permissions not already checked in checkQuickPermissions
1959          *
1960          * @param $action String the action to check
1961          * @param $user User to check
1962          * @param $errors Array list of current errors
1963          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1964          * @param $short Boolean short circuit on first error
1965          *
1966          * @return Array list of errors
1967          */
1968         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1969                 global $wgDeleteRevisionsLimit, $wgLang;
1970
1971                 if ( $action == 'protect' ) {
1972                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1973                                 // If they can't edit, they shouldn't protect.
1974                                 $errors[] = array( 'protect-cantedit' );
1975                         }
1976                 } elseif ( $action == 'create' ) {
1977                         $title_protection = $this->getTitleProtection();
1978                         if( $title_protection ) {
1979                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1980                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1981                                 }
1982                                 if( $title_protection['pt_create_perm'] == '' ||
1983                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1984                                 {
1985                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1986                                 }
1987                         }
1988                 } elseif ( $action == 'move' ) {
1989                         // Check for immobile pages
1990                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1991                                 // Specific message for this case
1992                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1993                         } elseif ( !$this->isMovable() ) {
1994                                 // Less specific message for rarer cases
1995                                 $errors[] = array( 'immobile-source-page' );
1996                         }
1997                 } elseif ( $action == 'move-target' ) {
1998                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1999                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2000                         } elseif ( !$this->isMovable() ) {
2001                                 $errors[] = array( 'immobile-target-page' );
2002                         }
2003                 } elseif ( $action == 'delete' ) {
2004                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2005                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
2006                         {
2007                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2008                         }
2009                 }
2010                 return $errors;
2011         }
2012
2013         /**
2014          * Check that the user isn't blocked from editting.
2015          *
2016          * @param $action String the action to check
2017          * @param $user User to check
2018          * @param $errors Array list of current errors
2019          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2020          * @param $short Boolean short circuit on first error
2021          *
2022          * @return Array list of errors
2023          */
2024         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2025                 // Account creation blocks handled at userlogin.
2026                 // Unblocking handled in SpecialUnblock
2027                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2028                         return $errors;
2029                 }
2030
2031                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
2032
2033                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2034                         $errors[] = array( 'confirmedittext' );
2035                 }
2036
2037                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2038                         // Don't block the user from editing their own talk page unless they've been
2039                         // explicitly blocked from that too.
2040                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2041                         $block = $user->getBlock();
2042
2043                         // This is from OutputPage::blockedPage
2044                         // Copied at r23888 by werdna
2045
2046                         $id = $user->blockedBy();
2047                         $reason = $user->blockedFor();
2048                         if ( $reason == '' ) {
2049                                 $reason = wfMessage( 'blockednoreason' )->text();
2050                         }
2051                         $ip = $user->getRequest()->getIP();
2052
2053                         if ( is_numeric( $id ) ) {
2054                                 $name = User::whoIs( $id );
2055                         } else {
2056                                 $name = $id;
2057                         }
2058
2059                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2060                         $blockid = $block->getId();
2061                         $blockExpiry = $block->getExpiry();
2062                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2063                         if ( $blockExpiry == 'infinity' ) {
2064                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2065                         } else {
2066                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2067                         }
2068
2069                         $intended = strval( $block->getTarget() );
2070
2071                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2072                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2073                 }
2074
2075                 return $errors;
2076         }
2077
2078         /**
2079          * Check that the user is allowed to read this page.
2080          *
2081          * @param $action String the action to check
2082          * @param $user User to check
2083          * @param $errors Array list of current errors
2084          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2085          * @param $short Boolean short circuit on first error
2086          *
2087          * @return Array list of errors
2088          */
2089         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2090                 global $wgWhitelistRead, $wgRevokePermissions;
2091                 static $useShortcut = null;
2092
2093                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2094                 if ( is_null( $useShortcut ) ) {
2095                         $useShortcut = true;
2096                         if ( !User::groupHasPermission( '*', 'read' ) ) {
2097                                 # Not a public wiki, so no shortcut
2098                                 $useShortcut = false;
2099                         } elseif ( !empty( $wgRevokePermissions ) ) {
2100                                 /**
2101                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2102                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2103                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2104                                  * reading is allowed.
2105                                  */
2106                                 foreach ( $wgRevokePermissions as $perms ) {
2107                                         if ( !empty( $perms['read'] ) ) {
2108                                                 # We might be removing the read right from the user, so no shortcut
2109                                                 $useShortcut = false;
2110                                                 break;
2111                                         }
2112                                 }
2113                         }
2114                 }
2115
2116                 $whitelisted = false;
2117                 if ( $useShortcut ) {
2118                         # Shortcut for public wikis, allows skipping quite a bit of code
2119                         $whitelisted = true;
2120                 } elseif ( $user->isAllowed( 'read' ) ) {
2121                         # If the user is allowed to read pages, he is allowed to read all pages
2122                         $whitelisted = true;
2123                 } elseif ( $this->isSpecial( 'Userlogin' )
2124                         || $this->isSpecial( 'ChangePassword' )
2125                         || $this->isSpecial( 'PasswordReset' )
2126                 ) {
2127                         # Always grant access to the login page.
2128                         # Even anons need to be able to log in.
2129                         $whitelisted = true;
2130                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2131                         # Time to check the whitelist
2132                         # Only do these checks is there's something to check against
2133                         $name = $this->getPrefixedText();
2134                         $dbName = $this->getPrefixedDBKey();
2135
2136                         // Check for explicit whitelisting with and without underscores
2137                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2138                                 $whitelisted = true;
2139                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2140                                 # Old settings might have the title prefixed with
2141                                 # a colon for main-namespace pages
2142                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2143                                         $whitelisted = true;
2144                                 }
2145                         } elseif ( $this->isSpecialPage() ) {
2146                                 # If it's a special page, ditch the subpage bit and check again
2147                                 $name = $this->getDBkey();
2148                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2149                                 if ( $name !== false ) {
2150                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2151                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2152                                                 $whitelisted = true;
2153                                         }
2154                                 }
2155                         }
2156                 }
2157
2158                 if ( !$whitelisted ) {
2159                         # If the title is not whitelisted, give extensions a chance to do so...
2160                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2161                         if ( !$whitelisted ) {
2162                                 $errors[] = $this->missingPermissionError( $action, $short );
2163                         }
2164                 }
2165
2166                 return $errors;
2167         }
2168
2169         /**
2170          * Get a description array when the user doesn't have the right to perform
2171          * $action (i.e. when User::isAllowed() returns false)
2172          *
2173          * @param $action String the action to check
2174          * @param $short Boolean short circuit on first error
2175          * @return Array list of errors
2176          */
2177         private function missingPermissionError( $action, $short ) {
2178                 // We avoid expensive display logic for quickUserCan's and such
2179                 if ( $short ) {
2180                         return array( 'badaccess-group0' );
2181                 }
2182
2183                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2184                         User::getGroupsWithPermission( $action ) );
2185
2186                 if ( count( $groups ) ) {
2187                         global $wgLang;
2188                         return array(
2189                                 'badaccess-groups',
2190                                 $wgLang->commaList( $groups ),
2191                                 count( $groups )
2192                         );
2193                 } else {
2194                         return array( 'badaccess-group0' );
2195                 }
2196         }
2197
2198         /**
2199          * Can $user perform $action on this page? This is an internal function,
2200          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2201          * checks on wfReadOnly() and blocks)
2202          *
2203          * @param $action String action that permission needs to be checked for
2204          * @param $user User to check
2205          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2206          * @param $short Bool Set this to true to stop after the first permission error.
2207          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2208          */
2209         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2210                 wfProfileIn( __METHOD__ );
2211
2212                 # Read has special handling
2213                 if ( $action == 'read' ) {
2214                         $checks = array(
2215                                 'checkPermissionHooks',
2216                                 'checkReadPermissions',
2217                         );
2218                 } else {
2219                         $checks = array(
2220                                 'checkQuickPermissions',
2221                                 'checkPermissionHooks',
2222                                 'checkSpecialsAndNSPermissions',
2223                                 'checkCSSandJSPermissions',
2224                                 'checkPageRestrictions',
2225                                 'checkCascadingSourcesRestrictions',
2226                                 'checkActionPermissions',
2227                                 'checkUserBlock'
2228                         );
2229                 }
2230
2231                 $errors = array();
2232                 while( count( $checks ) > 0 &&
2233                                 !( $short && count( $errors ) > 0 ) ) {
2234                         $method = array_shift( $checks );
2235                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2236                 }
2237
2238                 wfProfileOut( __METHOD__ );
2239                 return $errors;
2240         }
2241
2242         /**
2243          * Protect css subpages of user pages: can $wgUser edit
2244          * this page?
2245          *
2246          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2247          * @return Bool
2248          */
2249         public function userCanEditCssSubpage() {
2250                 global $wgUser;
2251                 wfDeprecated( __METHOD__, '1.19' );
2252                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2253                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2254         }
2255
2256         /**
2257          * Protect js subpages of user pages: can $wgUser edit
2258          * this page?
2259          *
2260          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2261          * @return Bool
2262          */
2263         public function userCanEditJsSubpage() {
2264                 global $wgUser;
2265                 wfDeprecated( __METHOD__, '1.19' );
2266                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2267                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2268         }
2269
2270         /**
2271          * Get a filtered list of all restriction types supported by this wiki.
2272          * @param bool $exists True to get all restriction types that apply to
2273          * titles that do exist, False for all restriction types that apply to
2274          * titles that do not exist
2275          * @return array
2276          */
2277         public static function getFilteredRestrictionTypes( $exists = true ) {
2278                 global $wgRestrictionTypes;
2279                 $types = $wgRestrictionTypes;
2280                 if ( $exists ) {
2281                         # Remove the create restriction for existing titles
2282                         $types = array_diff( $types, array( 'create' ) );
2283                 } else {
2284                         # Only the create and upload restrictions apply to non-existing titles
2285                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2286                 }
2287                 return $types;
2288         }
2289
2290         /**
2291          * Returns restriction types for the current Title
2292          *
2293          * @return array applicable restriction types
2294          */
2295         public function getRestrictionTypes() {
2296                 if ( $this->isSpecialPage() ) {
2297                         return array();
2298                 }
2299
2300                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2301
2302                 if ( $this->getNamespace() != NS_FILE ) {
2303                         # Remove the upload restriction for non-file titles
2304                         $types = array_diff( $types, array( 'upload' ) );
2305                 }
2306
2307                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2308
2309                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2310                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2311
2312                 return $types;
2313         }
2314
2315         /**
2316          * Is this title subject to title protection?
2317          * Title protection is the one applied against creation of such title.
2318          *
2319          * @return Mixed An associative array representing any existent title
2320          *   protection, or false if there's none.
2321          */
2322         private function getTitleProtection() {
2323                 // Can't protect pages in special namespaces
2324                 if ( $this->getNamespace() < 0 ) {
2325                         return false;
2326                 }
2327
2328                 // Can't protect pages that exist.
2329                 if ( $this->exists() ) {
2330                         return false;
2331                 }
2332
2333                 if ( !isset( $this->mTitleProtection ) ) {
2334                         $dbr = wfGetDB( DB_SLAVE );
2335                         $res = $dbr->select( 'protected_titles', '*',
2336                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2337                                 __METHOD__ );
2338
2339                         // fetchRow returns false if there are no rows.
2340                         $this->mTitleProtection = $dbr->fetchRow( $res );
2341                 }
2342                 return $this->mTitleProtection;
2343         }
2344
2345         /**
2346          * Update the title protection status
2347          *
2348          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2349          * @param $create_perm String Permission required for creation
2350          * @param $reason String Reason for protection
2351          * @param $expiry String Expiry timestamp
2352          * @return boolean true
2353          */
2354         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2355                 wfDeprecated( __METHOD__, '1.19' );
2356
2357                 global $wgUser;
2358
2359                 $limit = array( 'create' => $create_perm );
2360                 $expiry = array( 'create' => $expiry );
2361
2362                 $page = WikiPage::factory( $this );
2363                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2364
2365                 return $status->isOK();
2366         }
2367
2368         /**
2369          * Remove any title protection due to page existing
2370          */
2371         public function deleteTitleProtection() {
2372                 $dbw = wfGetDB( DB_MASTER );
2373
2374                 $dbw->delete(
2375                         'protected_titles',
2376                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2377                         __METHOD__
2378                 );
2379                 $this->mTitleProtection = false;
2380         }
2381
2382         /**
2383          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2384          *
2385          * @param $action String Action to check (default: edit)
2386          * @return Bool
2387          */
2388         public function isSemiProtected( $action = 'edit' ) {
2389                 if ( $this->exists() ) {
2390                         $restrictions = $this->getRestrictions( $action );
2391                         if ( count( $restrictions ) > 0 ) {
2392                                 foreach ( $restrictions as $restriction ) {
2393                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2394                                                 return false;
2395                                         }
2396                                 }
2397                         } else {
2398                                 # Not protected
2399                                 return false;
2400                         }
2401                         return true;
2402                 } else {
2403                         # If it doesn't exist, it can't be protected
2404                         return false;
2405                 }
2406         }
2407
2408         /**
2409          * Does the title correspond to a protected article?
2410          *
2411          * @param $action String the action the page is protected from,
2412          * by default checks all actions.
2413          * @return Bool
2414          */
2415         public function isProtected( $action = '' ) {
2416                 global $wgRestrictionLevels;
2417
2418                 $restrictionTypes = $this->getRestrictionTypes();
2419
2420                 # Special pages have inherent protection
2421                 if( $this->isSpecialPage() ) {
2422                         return true;
2423                 }
2424
2425                 # Check regular protection levels
2426                 foreach ( $restrictionTypes as $type ) {
2427                         if ( $action == $type || $action == '' ) {
2428                                 $r = $this->getRestrictions( $type );
2429                                 foreach ( $wgRestrictionLevels as $level ) {
2430                                         if ( in_array( $level, $r ) && $level != '' ) {
2431                                                 return true;
2432                                         }
2433                                 }
2434                         }
2435                 }
2436
2437                 return false;
2438         }
2439
2440         /**
2441          * Determines if $user is unable to edit this page because it has been protected
2442          * by $wgNamespaceProtection.
2443          *
2444          * @param $user User object to check permissions
2445          * @return Bool
2446          */
2447         public function isNamespaceProtected( User $user ) {
2448                 global $wgNamespaceProtection;
2449
2450                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2451                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2452                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2453                                         return true;
2454                                 }
2455                         }
2456                 }
2457                 return false;
2458         }
2459
2460         /**
2461          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2462          *
2463          * @return Bool If the page is subject to cascading restrictions.
2464          */
2465         public function isCascadeProtected() {
2466                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2467                 return ( $sources > 0 );
2468         }
2469
2470         /**
2471          * Cascading protection: Get the source of any cascading restrictions on this page.
2472          *
2473          * @param $getPages Bool Whether or not to retrieve the actual pages
2474          *        that the restrictions have come from.
2475          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2476          *     have come, false for none, or true if such restrictions exist, but $getPages
2477          *     was not set.  The restriction array is an array of each type, each of which
2478          *     contains a array of unique groups.
2479          */
2480         public function getCascadeProtectionSources( $getPages = true ) {
2481                 global $wgContLang;
2482                 $pagerestrictions = array();
2483
2484                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2485                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2486                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2487                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2488                 }
2489
2490                 wfProfileIn( __METHOD__ );
2491
2492                 $dbr = wfGetDB( DB_SLAVE );
2493
2494                 if ( $this->getNamespace() == NS_FILE ) {
2495                         $tables = array( 'imagelinks', 'page_restrictions' );
2496                         $where_clauses = array(
2497                                 'il_to' => $this->getDBkey(),
2498                                 'il_from=pr_page',
2499                                 'pr_cascade' => 1
2500                         );
2501                 } else {
2502                         $tables = array( 'templatelinks', 'page_restrictions' );
2503                         $where_clauses = array(
2504                                 'tl_namespace' => $this->getNamespace(),
2505                                 'tl_title' => $this->getDBkey(),
2506                                 'tl_from=pr_page',
2507                                 'pr_cascade' => 1
2508                         );
2509                 }
2510
2511                 if ( $getPages ) {
2512                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2513                                                    'pr_expiry', 'pr_type', 'pr_level' );
2514                         $where_clauses[] = 'page_id=pr_page';
2515                         $tables[] = 'page';
2516                 } else {
2517                         $cols = array( 'pr_expiry' );
2518                 }
2519
2520                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2521
2522                 $sources = $getPages ? array() : false;
2523                 $now = wfTimestampNow();
2524                 $purgeExpired = false;
2525
2526                 foreach ( $res as $row ) {
2527                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2528                         if ( $expiry > $now ) {
2529                                 if ( $getPages ) {
2530                                         $page_id = $row->pr_page;
2531                                         $page_ns = $row->page_namespace;
2532                                         $page_title = $row->page_title;
2533                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2534                                         # Add groups needed for each restriction type if its not already there
2535                                         # Make sure this restriction type still exists
2536
2537                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2538                                                 $pagerestrictions[$row->pr_type] = array();
2539                                         }
2540
2541                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2542                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2543                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2544                                         }
2545                                 } else {
2546                                         $sources = true;
2547                                 }
2548                         } else {
2549                                 // Trigger lazy purge of expired restrictions from the db
2550                                 $purgeExpired = true;
2551                         }
2552                 }
2553                 if ( $purgeExpired ) {
2554                         Title::purgeExpiredRestrictions();
2555                 }
2556
2557                 if ( $getPages ) {
2558                         $this->mCascadeSources = $sources;
2559                         $this->mCascadingRestrictions = $pagerestrictions;
2560                 } else {
2561                         $this->mHasCascadingRestrictions = $sources;
2562                 }
2563
2564                 wfProfileOut( __METHOD__ );
2565                 return array( $sources, $pagerestrictions );
2566         }
2567
2568         /**
2569          * Accessor/initialisation for mRestrictions
2570          *
2571          * @param $action String action that permission needs to be checked for
2572          * @return Array of Strings the array of groups allowed to edit this article
2573          */
2574         public function getRestrictions( $action ) {
2575                 if ( !$this->mRestrictionsLoaded ) {
2576                         $this->loadRestrictions();
2577                 }
2578                 return isset( $this->mRestrictions[$action] )
2579                                 ? $this->mRestrictions[$action]
2580                                 : array();
2581         }
2582
2583         /**
2584          * Get the expiry time for the restriction against a given action
2585          *
2586          * @param $action
2587          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2588          *     or not protected at all, or false if the action is not recognised.
2589          */
2590         public function getRestrictionExpiry( $action ) {
2591                 if ( !$this->mRestrictionsLoaded ) {
2592                         $this->loadRestrictions();
2593                 }
2594                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2595         }
2596
2597         /**
2598          * Returns cascading restrictions for the current article
2599          *
2600          * @return Boolean
2601          */
2602         function areRestrictionsCascading() {
2603                 if ( !$this->mRestrictionsLoaded ) {
2604                         $this->loadRestrictions();
2605                 }
2606
2607                 return $this->mCascadeRestriction;
2608         }
2609
2610         /**
2611          * Loads a string into mRestrictions array
2612          *
2613          * @param $res Resource restrictions as an SQL result.
2614          * @param $oldFashionedRestrictions String comma-separated list of page
2615          *        restrictions from page table (pre 1.10)
2616          */
2617         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2618                 $rows = array();
2619
2620                 foreach ( $res as $row ) {
2621                         $rows[] = $row;
2622                 }
2623
2624                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2625         }
2626
2627         /**
2628          * Compiles list of active page restrictions from both page table (pre 1.10)
2629          * and page_restrictions table for this existing page.
2630          * Public for usage by LiquidThreads.
2631          *
2632          * @param $rows array of db result objects
2633          * @param $oldFashionedRestrictions string comma-separated list of page
2634          *        restrictions from page table (pre 1.10)
2635          */
2636         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2637                 global $wgContLang;
2638                 $dbr = wfGetDB( DB_SLAVE );
2639
2640                 $restrictionTypes = $this->getRestrictionTypes();
2641
2642                 foreach ( $restrictionTypes as $type ) {
2643                         $this->mRestrictions[$type] = array();
2644                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2645                 }
2646
2647                 $this->mCascadeRestriction = false;
2648
2649                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2650
2651                 if ( $oldFashionedRestrictions === null ) {
2652                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2653                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2654                 }
2655
2656                 if ( $oldFashionedRestrictions != '' ) {
2657
2658                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2659                                 $temp = explode( '=', trim( $restrict ) );
2660                                 if ( count( $temp ) == 1 ) {
2661                                         // old old format should be treated as edit/move restriction
2662                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2663                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2664                                 } else {
2665                                         $restriction = trim( $temp[1] );
2666                                         if( $restriction != '' ) { //some old entries are empty
2667                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2668                                         }
2669                                 }
2670                         }
2671
2672                         $this->mOldRestrictions = true;
2673
2674                 }
2675
2676                 if ( count( $rows ) ) {
2677                         # Current system - load second to make them override.
2678                         $now = wfTimestampNow();
2679                         $purgeExpired = false;
2680
2681                         # Cycle through all the restrictions.
2682                         foreach ( $rows as $row ) {
2683
2684                                 // Don't take care of restrictions types that aren't allowed
2685                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2686                                         continue;
2687
2688                                 // This code should be refactored, now that it's being used more generally,
2689                                 // But I don't really see any harm in leaving it in Block for now -werdna
2690                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2691
2692                                 // Only apply the restrictions if they haven't expired!
2693                                 if ( !$expiry || $expiry > $now ) {
2694                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2695                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2696
2697                                         $this->mCascadeRestriction |= $row->pr_cascade;
2698                                 } else {
2699                                         // Trigger a lazy purge of expired restrictions
2700                                         $purgeExpired = true;
2701                                 }
2702                         }
2703
2704                         if ( $purgeExpired ) {
2705                                 Title::purgeExpiredRestrictions();
2706                         }
2707                 }
2708
2709                 $this->mRestrictionsLoaded = true;
2710         }
2711
2712         /**
2713          * Load restrictions from the page_restrictions table
2714          *
2715          * @param $oldFashionedRestrictions String comma-separated list of page
2716          *        restrictions from page table (pre 1.10)
2717          */
2718         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2719                 global $wgContLang;
2720                 if ( !$this->mRestrictionsLoaded ) {
2721                         if ( $this->exists() ) {
2722                                 $dbr = wfGetDB( DB_SLAVE );
2723
2724                                 $res = $dbr->select(
2725                                         'page_restrictions',
2726                                         '*',
2727                                         array( 'pr_page' => $this->getArticleID() ),
2728                                         __METHOD__
2729                                 );
2730
2731                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2732                         } else {
2733                                 $title_protection = $this->getTitleProtection();
2734
2735                                 if ( $title_protection ) {
2736                                         $now = wfTimestampNow();
2737                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2738
2739                                         if ( !$expiry || $expiry > $now ) {
2740                                                 // Apply the restrictions
2741                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2742                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2743                                         } else { // Get rid of the old restrictions
2744                                                 Title::purgeExpiredRestrictions();
2745                                                 $this->mTitleProtection = false;
2746                                         }
2747                                 } else {
2748                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2749                                 }
2750                                 $this->mRestrictionsLoaded = true;
2751                         }
2752                 }
2753         }
2754
2755         /**
2756          * Flush the protection cache in this object and force reload from the database.
2757          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2758          */
2759         public function flushRestrictions() {
2760                 $this->mRestrictionsLoaded = false;
2761                 $this->mTitleProtection = null;
2762         }
2763
2764         /**
2765          * Purge expired restrictions from the page_restrictions table
2766          */
2767         static function purgeExpiredRestrictions() {
2768                 $dbw = wfGetDB( DB_MASTER );
2769                 $dbw->delete(
2770                         'page_restrictions',
2771                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2772                         __METHOD__
2773                 );
2774
2775                 $dbw->delete(
2776                         'protected_titles',
2777                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2778                         __METHOD__
2779                 );
2780         }
2781
2782         /**
2783          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2784          *
2785          * @return Bool
2786          */
2787         public function hasSubpages() {
2788                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2789                         # Duh
2790                         return false;
2791                 }
2792
2793                 # We dynamically add a member variable for the purpose of this method
2794                 # alone to cache the result.  There's no point in having it hanging
2795                 # around uninitialized in every Title object; therefore we only add it
2796                 # if needed and don't declare it statically.
2797                 if ( isset( $this->mHasSubpages ) ) {
2798                         return $this->mHasSubpages;
2799                 }
2800
2801                 $subpages = $this->getSubpages( 1 );
2802                 if ( $subpages instanceof TitleArray ) {
2803                         return $this->mHasSubpages = (bool)$subpages->count();
2804                 }
2805                 return $this->mHasSubpages = false;
2806         }
2807
2808         /**
2809          * Get all subpages of this page.
2810          *
2811          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2812          * @return mixed TitleArray, or empty array if this page's namespace
2813          *  doesn't allow subpages
2814          */
2815         public function getSubpages( $limit = -1 ) {
2816                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2817                         return array();
2818                 }
2819
2820                 $dbr = wfGetDB( DB_SLAVE );
2821                 $conds['page_namespace'] = $this->getNamespace();
2822                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2823                 $options = array();
2824                 if ( $limit > -1 ) {
2825                         $options['LIMIT'] = $limit;
2826                 }
2827                 return $this->mSubpages = TitleArray::newFromResult(
2828                         $dbr->select( 'page',
2829                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2830                                 $conds,
2831                                 __METHOD__,
2832                                 $options
2833                         )
2834                 );
2835         }
2836
2837         /**
2838          * Is there a version of this page in the deletion archive?
2839          *
2840          * @return Int the number of archived revisions
2841          */
2842         public function isDeleted() {
2843                 if ( $this->getNamespace() < 0 ) {
2844                         $n = 0;
2845                 } else {
2846                         $dbr = wfGetDB( DB_SLAVE );
2847
2848                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2849                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2850                                 __METHOD__
2851                         );
2852                         if ( $this->getNamespace() == NS_FILE ) {
2853                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2854                                         array( 'fa_name' => $this->getDBkey() ),
2855                                         __METHOD__
2856                                 );
2857                         }
2858                 }
2859                 return (int)$n;
2860         }
2861
2862         /**
2863          * Is there a version of this page in the deletion archive?
2864          *
2865          * @return Boolean
2866          */
2867         public function isDeletedQuick() {
2868                 if ( $this->getNamespace() < 0 ) {
2869                         return false;
2870                 }
2871                 $dbr = wfGetDB( DB_SLAVE );
2872                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2873                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2874                         __METHOD__
2875                 );
2876                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2877                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2878                                 array( 'fa_name' => $this->getDBkey() ),
2879                                 __METHOD__
2880                         );
2881                 }
2882                 return $deleted;
2883         }
2884
2885         /**
2886          * Get the article ID for this Title from the link cache,
2887          * adding it if necessary
2888          *
2889          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2890          *  for update
2891          * @return Int the ID
2892          */
2893         public function getArticleID( $flags = 0 ) {
2894                 if ( $this->getNamespace() < 0 ) {
2895                         return $this->mArticleID = 0;
2896                 }
2897                 $linkCache = LinkCache::singleton();
2898                 if ( $flags & self::GAID_FOR_UPDATE ) {
2899                         $oldUpdate = $linkCache->forUpdate( true );
2900                         $linkCache->clearLink( $this );
2901                         $this->mArticleID = $linkCache->addLinkObj( $this );
2902                         $linkCache->forUpdate( $oldUpdate );
2903                 } else {
2904                         if ( -1 == $this->mArticleID ) {
2905                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2906                         }
2907                 }
2908                 return $this->mArticleID;
2909         }
2910
2911         /**
2912          * Is this an article that is a redirect page?
2913          * Uses link cache, adding it if necessary
2914          *
2915          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2916          * @return Bool
2917          */
2918         public function isRedirect( $flags = 0 ) {
2919                 if ( !is_null( $this->mRedirect ) ) {
2920                         return $this->mRedirect;
2921                 }
2922                 # Calling getArticleID() loads the field from cache as needed
2923                 if ( !$this->getArticleID( $flags ) ) {
2924                         return $this->mRedirect = false;
2925                 }
2926
2927                 $linkCache = LinkCache::singleton();
2928                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2929                 if ( $cached === null ) {
2930                         // TODO: check the assumption that the cache actually knows about this title
2931                         // and handle this, such as get the title from the database.
2932                         // See https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2933                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2934                         wfDebug( wfBacktrace() );
2935                 }
2936
2937                 $this->mRedirect = (bool)$cached;
2938
2939                 return $this->mRedirect;
2940         }
2941
2942         /**
2943          * What is the length of this page?
2944          * Uses link cache, adding it if necessary
2945          *
2946          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2947          * @return Int
2948          */
2949         public function getLength( $flags = 0 ) {
2950                 if ( $this->mLength != -1 ) {
2951                         return $this->mLength;
2952                 }
2953                 # Calling getArticleID() loads the field from cache as needed
2954                 if ( !$this->getArticleID( $flags ) ) {
2955                         return $this->mLength = 0;
2956                 }
2957                 $linkCache = LinkCache::singleton();
2958                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2959                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2960                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2961                         #      as a stop gap, perhaps log this, but don't throw an exception?
2962                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2963                         wfDebug( wfBacktrace() );
2964                 }
2965
2966                 $this->mLength = intval( $cached );
2967
2968                 return $this->mLength;
2969         }
2970
2971         /**
2972          * What is the page_latest field for this page?
2973          *
2974          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2975          * @return Int or 0 if the page doesn't exist
2976          */
2977         public function getLatestRevID( $flags = 0 ) {
2978                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
2979                         return intval( $this->mLatestID );
2980                 }
2981                 # Calling getArticleID() loads the field from cache as needed
2982                 if ( !$this->getArticleID( $flags ) ) {
2983                         return $this->mLatestID = 0;
2984                 }
2985                 $linkCache = LinkCache::singleton();
2986                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
2987                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2988                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2989                         #      as a stop gap, perhaps log this, but don't throw an exception?
2990                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2991                 }
2992
2993                 $this->mLatestID = intval( $cached );
2994
2995                 return $this->mLatestID;
2996         }
2997
2998         /**
2999          * This clears some fields in this object, and clears any associated
3000          * keys in the "bad links" section of the link cache.
3001          *
3002          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3003          * loading of the new page_id. It's also called from
3004          * WikiPage::doDeleteArticleReal()
3005          *
3006          * @param $newid Int the new Article ID
3007          */
3008         public function resetArticleID( $newid ) {
3009                 $linkCache = LinkCache::singleton();
3010                 $linkCache->clearLink( $this );
3011
3012                 if ( $newid === false ) {
3013                         $this->mArticleID = -1;
3014                 } else {
3015                         $this->mArticleID = intval( $newid );
3016                 }
3017                 $this->mRestrictionsLoaded = false;
3018                 $this->mRestrictions = array();
3019                 $this->mRedirect = null;
3020                 $this->mLength = -1;
3021                 $this->mLatestID = false;
3022                 $this->mContentModel = false;
3023                 $this->mEstimateRevisions = null;
3024         }
3025
3026         /**
3027          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3028          *
3029          * @param $text String containing title to capitalize
3030          * @param $ns int namespace index, defaults to NS_MAIN
3031          * @return String containing capitalized title
3032          */
3033         public static function capitalize( $text, $ns = NS_MAIN ) {
3034                 global $wgContLang;
3035
3036                 if ( MWNamespace::isCapitalized( $ns ) ) {
3037                         return $wgContLang->ucfirst( $text );
3038                 } else {
3039                         return $text;
3040                 }
3041         }
3042
3043         /**
3044          * Secure and split - main initialisation function for this object
3045          *
3046          * Assumes that mDbkeyform has been set, and is urldecoded
3047          * and uses underscores, but not otherwise munged.  This function
3048          * removes illegal characters, splits off the interwiki and
3049          * namespace prefixes, sets the other forms, and canonicalizes
3050          * everything.
3051          *
3052          * @return Bool true on success
3053          */
3054         private function secureAndSplit() {
3055                 global $wgContLang, $wgLocalInterwiki;
3056
3057                 # Initialisation
3058                 $this->mInterwiki = $this->mFragment = '';
3059                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3060
3061                 $dbkey = $this->mDbkeyform;
3062
3063                 # Strip Unicode bidi override characters.
3064                 # Sometimes they slip into cut-n-pasted page titles, where the
3065                 # override chars get included in list displays.
3066                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3067
3068                 # Clean up whitespace
3069                 # Note: use of the /u option on preg_replace here will cause
3070                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3071                 # conveniently disabling them.
3072                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3073                 $dbkey = trim( $dbkey, '_' );
3074
3075                 if ( $dbkey == '' ) {
3076                         return false;
3077                 }
3078
3079                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3080                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3081                         return false;
3082                 }
3083
3084                 $this->mDbkeyform = $dbkey;
3085
3086                 # Initial colon indicates main namespace rather than specified default
3087                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3088                 if ( ':' == $dbkey[0] ) {
3089                         $this->mNamespace = NS_MAIN;
3090                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3091                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3092                 }
3093
3094                 # Namespace or interwiki prefix
3095                 $firstPass = true;
3096                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3097                 do {
3098                         $m = array();
3099                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3100                                 $p = $m[1];
3101                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3102                                         # Ordinary namespace
3103                                         $dbkey = $m[2];
3104                                         $this->mNamespace = $ns;
3105                                         # For Talk:X pages, check if X has a "namespace" prefix
3106                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3107                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3108                                                         # Disallow Talk:File:x type titles...
3109                                                         return false;
3110                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3111                                                         # Disallow Talk:Interwiki:x type titles...
3112                                                         return false;
3113                                                 }
3114                                         }
3115                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3116                                         if ( !$firstPass ) {
3117                                                 # Can't make a local interwiki link to an interwiki link.
3118                                                 # That's just crazy!
3119                                                 return false;
3120                                         }
3121
3122                                         # Interwiki link
3123                                         $dbkey = $m[2];
3124                                         $this->mInterwiki = $wgContLang->lc( $p );
3125
3126                                         # Redundant interwiki prefix to the local wiki
3127                                         if ( $wgLocalInterwiki !== false
3128                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3129                                         {
3130                                                 if ( $dbkey == '' ) {
3131                                                         # Can't have an empty self-link
3132                                                         return false;
3133                                                 }
3134                                                 $this->mInterwiki = '';
3135                                                 $firstPass = false;
3136                                                 # Do another namespace split...
3137                                                 continue;
3138                                         }
3139
3140                                         # If there's an initial colon after the interwiki, that also
3141                                         # resets the default namespace
3142                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3143                                                 $this->mNamespace = NS_MAIN;
3144                                                 $dbkey = substr( $dbkey, 1 );
3145                                         }
3146                                 }
3147                                 # If there's no recognized interwiki or namespace,
3148                                 # then let the colon expression be part of the title.
3149                         }
3150                         break;
3151                 } while ( true );
3152
3153                 # We already know that some pages won't be in the database!
3154                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3155                         $this->mArticleID = 0;
3156                 }
3157                 $fragment = strstr( $dbkey, '#' );
3158                 if ( false !== $fragment ) {
3159                         $this->setFragment( $fragment );
3160                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3161                         # remove whitespace again: prevents "Foo_bar_#"
3162                         # becoming "Foo_bar_"
3163                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3164                 }
3165
3166                 # Reject illegal characters.
3167                 $rxTc = self::getTitleInvalidRegex();
3168                 if ( preg_match( $rxTc, $dbkey ) ) {
3169                         return false;
3170                 }
3171
3172                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3173                 # reachable due to the way web browsers deal with 'relative' URLs.
3174                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3175                 if ( strpos( $dbkey, '.' ) !== false &&
3176                          ( $dbkey === '.' || $dbkey === '..' ||
3177                            strpos( $dbkey, './' ) === 0  ||
3178                            strpos( $dbkey, '../' ) === 0 ||
3179                            strpos( $dbkey, '/./' ) !== false ||
3180                            strpos( $dbkey, '/../' ) !== false  ||
3181                            substr( $dbkey, -2 ) == '/.' ||
3182                            substr( $dbkey, -3 ) == '/..' ) )
3183                 {
3184                         return false;
3185                 }
3186
3187                 # Magic tilde sequences? Nu-uh!
3188                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3189                         return false;
3190                 }
3191
3192                 # Limit the size of titles to 255 bytes. This is typically the size of the
3193                 # underlying database field. We make an exception for special pages, which
3194                 # don't need to be stored in the database, and may edge over 255 bytes due
3195                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3196                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3197                   strlen( $dbkey ) > 512 )
3198                 {
3199                         return false;
3200                 }
3201
3202                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3203                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3204                 # other site might be case-sensitive.
3205                 $this->mUserCaseDBKey = $dbkey;
3206                 if ( $this->mInterwiki == '' ) {
3207                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3208                 }
3209
3210                 # Can't make a link to a namespace alone... "empty" local links can only be
3211                 # self-links with a fragment identifier.
3212                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3213                         return false;
3214                 }
3215
3216                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3217                 // IP names are not allowed for accounts, and can only be referring to
3218                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3219                 // there are numerous ways to present the same IP. Having sp:contribs scan
3220                 // them all is silly and having some show the edits and others not is
3221                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3222                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3223                         ? IP::sanitizeIP( $dbkey )
3224                         : $dbkey;
3225
3226                 // Any remaining initial :s are illegal.
3227                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3228                         return false;
3229                 }
3230
3231                 # Fill fields
3232                 $this->mDbkeyform = $dbkey;
3233                 $this->mUrlform = wfUrlencode( $dbkey );
3234
3235                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3236
3237                 return true;
3238         }
3239
3240         /**
3241          * Get an array of Title objects linking to this Title
3242          * Also stores the IDs in the link cache.
3243          *
3244          * WARNING: do not use this function on arbitrary user-supplied titles!
3245          * On heavily-used templates it will max out the memory.
3246          *
3247          * @param $options Array: may be FOR UPDATE
3248          * @param $table String: table name
3249          * @param $prefix String: fields prefix
3250          * @return Array of Title objects linking here
3251          */
3252         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3253                 if ( count( $options ) > 0 ) {
3254                         $db = wfGetDB( DB_MASTER );
3255                 } else {
3256                         $db = wfGetDB( DB_SLAVE );
3257                 }
3258
3259                 $res = $db->select(
3260                         array( 'page', $table ),
3261                         self::getSelectFields(),
3262                         array(
3263                                 "{$prefix}_from=page_id",
3264                                 "{$prefix}_namespace" => $this->getNamespace(),
3265                                 "{$prefix}_title"     => $this->getDBkey() ),
3266                         __METHOD__,
3267                         $options
3268                 );
3269
3270                 $retVal = array();
3271                 if ( $res->numRows() ) {
3272                         $linkCache = LinkCache::singleton();
3273                         foreach ( $res as $row ) {
3274                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3275                                 if ( $titleObj ) {
3276                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3277                                         $retVal[] = $titleObj;
3278                                 }
3279                         }
3280                 }
3281                 return $retVal;
3282         }
3283
3284         /**
3285          * Get an array of Title objects using this Title as a template
3286          * Also stores the IDs in the link cache.
3287          *
3288          * WARNING: do not use this function on arbitrary user-supplied titles!
3289          * On heavily-used templates it will max out the memory.
3290          *
3291          * @param $options Array: may be FOR UPDATE
3292          * @return Array of Title the Title objects linking here
3293          */
3294         public function getTemplateLinksTo( $options = array() ) {
3295                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3296         }
3297
3298         /**
3299          * Get an array of Title objects linked from this Title
3300          * Also stores the IDs in the link cache.
3301          *
3302          * WARNING: do not use this function on arbitrary user-supplied titles!
3303          * On heavily-used templates it will max out the memory.
3304          *
3305          * @param $options Array: may be FOR UPDATE
3306          * @param $table String: table name
3307          * @param $prefix String: fields prefix
3308          * @return Array of Title objects linking here
3309          */
3310         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3311                 global $wgContentHandlerUseDB;
3312
3313                 $id = $this->getArticleID();
3314
3315                 # If the page doesn't exist; there can't be any link from this page
3316                 if ( !$id ) {
3317                         return array();
3318                 }
3319
3320                 if ( count( $options ) > 0 ) {
3321                         $db = wfGetDB( DB_MASTER );
3322                 } else {
3323                         $db = wfGetDB( DB_SLAVE );
3324                 }
3325
3326                 $namespaceFiled = "{$prefix}_namespace";
3327                 $titleField = "{$prefix}_title";
3328
3329                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3330                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3331
3332                 $res = $db->select(
3333                         array( $table, 'page' ),
3334                         $fields,
3335                         array( "{$prefix}_from" => $id ),
3336                         __METHOD__,
3337                         $options,
3338                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3339                 );
3340
3341                 $retVal = array();
3342                 if ( $res->numRows() ) {
3343                         $linkCache = LinkCache::singleton();
3344                         foreach ( $res as $row ) {
3345                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3346                                 if ( $titleObj ) {
3347                                         if ( $row->page_id ) {
3348                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3349                                         } else {
3350                                                 $linkCache->addBadLinkObj( $titleObj );
3351                                         }
3352                                         $retVal[] = $titleObj;
3353                                 }
3354                         }
3355                 }
3356                 return $retVal;
3357         }
3358
3359         /**
3360          * Get an array of Title objects used on this Title as a template
3361          * Also stores the IDs in the link cache.
3362          *
3363          * WARNING: do not use this function on arbitrary user-supplied titles!
3364          * On heavily-used templates it will max out the memory.
3365          *
3366          * @param $options Array: may be FOR UPDATE
3367          * @return Array of Title the Title objects used here
3368          */
3369         public function getTemplateLinksFrom( $options = array() ) {
3370                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3371         }
3372
3373         /**
3374          * Get an array of Title objects referring to non-existent articles linked from this page
3375          *
3376          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3377          * @return Array of Title the Title objects
3378          */
3379         public function getBrokenLinksFrom() {
3380                 if ( $this->getArticleID() == 0 ) {
3381                         # All links from article ID 0 are false positives
3382                         return array();
3383                 }
3384
3385                 $dbr = wfGetDB( DB_SLAVE );
3386                 $res = $dbr->select(
3387                         array( 'page', 'pagelinks' ),
3388                         array( 'pl_namespace', 'pl_title' ),
3389                         array(
3390                                 'pl_from' => $this->getArticleID(),
3391                                 'page_namespace IS NULL'
3392                         ),
3393                         __METHOD__, array(),
3394                         array(
3395                                 'page' => array(
3396                                         'LEFT JOIN',
3397                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3398                                 )
3399                         )
3400                 );
3401
3402                 $retVal = array();
3403                 foreach ( $res as $row ) {
3404                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3405                 }
3406                 return $retVal;
3407         }
3408
3409
3410         /**
3411          * Get a list of URLs to purge from the Squid cache when this
3412          * page changes
3413          *
3414          * @return Array of String the URLs
3415          */
3416         public function getSquidURLs() {
3417                 $urls = array(
3418                         $this->getInternalURL(),
3419                         $this->getInternalURL( 'action=history' )
3420                 );
3421
3422                 $pageLang = $this->getPageLanguage();
3423                 if ( $pageLang->hasVariants() ) {
3424                         $variants = $pageLang->getVariants();
3425                         foreach ( $variants as $vCode ) {
3426                                 $urls[] = $this->getInternalURL( '', $vCode );
3427                         }
3428                 }
3429
3430                 return $urls;
3431         }
3432
3433         /**
3434          * Purge all applicable Squid URLs
3435          */
3436         public function purgeSquid() {
3437                 global $wgUseSquid;
3438                 if ( $wgUseSquid ) {
3439                         $urls = $this->getSquidURLs();
3440                         $u = new SquidUpdate( $urls );
3441                         $u->doUpdate();
3442                 }
3443         }
3444
3445         /**
3446          * Move this page without authentication
3447          *
3448          * @param $nt Title the new page Title
3449          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3450          */
3451         public function moveNoAuth( &$nt ) {
3452                 return $this->moveTo( $nt, false );
3453         }
3454
3455         /**
3456          * Check whether a given move operation would be valid.
3457          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3458          *
3459          * @param $nt Title the new title
3460          * @param $auth Bool indicates whether $wgUser's permissions
3461          *  should be checked
3462          * @param $reason String is the log summary of the move, used for spam checking
3463          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3464          */
3465         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3466                 global $wgUser, $wgContentHandlerUseDB;
3467
3468                 $errors = array();
3469                 if ( !$nt ) {
3470                         // Normally we'd add this to $errors, but we'll get
3471                         // lots of syntax errors if $nt is not an object
3472                         return array( array( 'badtitletext' ) );
3473                 }
3474                 if ( $this->equals( $nt ) ) {
3475                         $errors[] = array( 'selfmove' );
3476                 }
3477                 if ( !$this->isMovable() ) {
3478                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3479                 }
3480                 if ( $nt->getInterwiki() != '' ) {
3481                         $errors[] = array( 'immobile-target-namespace-iw' );
3482                 }
3483                 if ( !$nt->isMovable() ) {
3484                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3485                 }
3486
3487                 $oldid = $this->getArticleID();
3488                 $newid = $nt->getArticleID();
3489
3490                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3491                         $errors[] = array( 'articleexists' );
3492                 }
3493                 if ( ( $this->getDBkey() == '' ) ||
3494                          ( !$oldid ) ||
3495                          ( $nt->getDBkey() == '' ) ) {
3496                         $errors[] = array( 'badarticleerror' );
3497                 }
3498
3499                 // Content model checks
3500                 if ( !$wgContentHandlerUseDB &&
3501                                 $this->getContentModel() !== $nt->getContentModel() ) {
3502                         // can't move a page if that would change the page's content model
3503                         $errors[] = array( 'bad-target-model',
3504                                                         ContentHandler::getLocalizedName( $this->getContentModel() ),
3505                                                         ContentHandler::getLocalizedName( $nt->getContentModel() ) );
3506                 }
3507
3508                 // Image-specific checks
3509                 if ( $this->getNamespace() == NS_FILE ) {
3510                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3511                 }
3512
3513                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3514                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3515                 }
3516
3517                 if ( $auth ) {
3518                         $errors = wfMergeErrorArrays( $errors,
3519                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3520                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3521                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3522                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3523                 }
3524
3525                 $match = EditPage::matchSummarySpamRegex( $reason );
3526                 if ( $match !== false ) {
3527                         // This is kind of lame, won't display nice
3528                         $errors[] = array( 'spamprotectiontext' );
3529                 }
3530
3531                 $err = null;
3532                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3533                         $errors[] = array( 'hookaborted', $err );
3534                 }
3535
3536                 # The move is allowed only if (1) the target doesn't exist, or
3537                 # (2) the target is a redirect to the source, and has no history
3538                 # (so we can undo bad moves right after they're done).
3539
3540                 if ( 0 != $newid ) { # Target exists; check for validity
3541                         if ( !$this->isValidMoveTarget( $nt ) ) {
3542                                 $errors[] = array( 'articleexists' );
3543                         }
3544                 } else {
3545                         $tp = $nt->getTitleProtection();
3546                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3547                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3548                                 $errors[] = array( 'cantmove-titleprotected' );
3549                         }
3550                 }
3551                 if ( empty( $errors ) ) {
3552                         return true;
3553                 }
3554                 return $errors;
3555         }
3556
3557         /**
3558          * Check if the requested move target is a valid file move target
3559          * @param Title $nt Target title
3560          * @return array List of errors
3561          */
3562         protected function validateFileMoveOperation( $nt ) {
3563                 global $wgUser;
3564
3565                 $errors = array();
3566
3567                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3568
3569                 $file = wfLocalFile( $this );
3570                 if ( $file->exists() ) {
3571                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3572                                 $errors[] = array( 'imageinvalidfilename' );
3573                         }
3574                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3575                                 $errors[] = array( 'imagetypemismatch' );
3576                         }
3577                 }
3578
3579                 if ( $nt->getNamespace() != NS_FILE ) {
3580                         $errors[] = array( 'imagenocrossnamespace' );
3581                         // From here we want to do checks on a file object, so if we can't
3582                         // create one, we must return.
3583                         return $errors;
3584                 }
3585
3586                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3587
3588                 $destFile = wfLocalFile( $nt );
3589                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3590                         $errors[] = array( 'file-exists-sharedrepo' );
3591                 }
3592
3593                 return $errors;
3594         }
3595
3596         /**
3597          * Move a title to a new location
3598          *
3599          * @param $nt Title the new title
3600          * @param $auth Bool indicates whether $wgUser's permissions
3601          *  should be checked
3602          * @param $reason String the reason for the move
3603          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3604          *  Ignored if the user doesn't have the suppressredirect right.
3605          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3606          */
3607         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3608                 global $wgUser;
3609                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3610                 if ( is_array( $err ) ) {
3611                         // Auto-block user's IP if the account was "hard" blocked
3612                         $wgUser->spreadAnyEditBlock();
3613                         return $err;
3614                 }
3615                 // Check suppressredirect permission
3616                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3617                         $createRedirect = true;
3618                 }
3619
3620                 // If it is a file, move it first.
3621                 // It is done before all other moving stuff is done because it's hard to revert.
3622                 $dbw = wfGetDB( DB_MASTER );
3623                 if ( $this->getNamespace() == NS_FILE ) {
3624                         $file = wfLocalFile( $this );
3625                         if ( $file->exists() ) {
3626                                 $status = $file->move( $nt );
3627                                 if ( !$status->isOk() ) {
3628                                         return $status->getErrorsArray();
3629                                 }
3630                         }
3631                         // Clear RepoGroup process cache
3632                         RepoGroup::singleton()->clearCache( $this );
3633                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3634                 }
3635
3636                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3637                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3638                 $protected = $this->isProtected();
3639
3640                 // Do the actual move
3641                 $this->moveToInternal( $nt, $reason, $createRedirect );
3642
3643                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3644                 // cl_timestamp, which may disturb time-based lists on some sites.
3645                 $prefixes = $dbw->select(
3646                         'categorylinks',
3647                         array( 'cl_sortkey_prefix', 'cl_to' ),
3648                         array( 'cl_from' => $pageid ),
3649                         __METHOD__
3650                 );
3651                 foreach ( $prefixes as $prefixRow ) {
3652                         $prefix = $prefixRow->cl_sortkey_prefix;
3653                         $catTo = $prefixRow->cl_to;
3654                         $dbw->update( 'categorylinks',
3655                                 array(
3656                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3657                                                 $nt->getCategorySortkey( $prefix ) ),
3658                                         'cl_timestamp=cl_timestamp' ),
3659                                 array(
3660                                         'cl_from' => $pageid,
3661                                         'cl_to' => $catTo ),
3662                                 __METHOD__
3663                         );
3664                 }
3665
3666                 $redirid = $this->getArticleID();
3667
3668                 if ( $protected ) {
3669                         # Protect the redirect title as the title used to be...
3670                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3671                                 array(
3672                                         'pr_page'    => $redirid,
3673                                         'pr_type'    => 'pr_type',
3674                                         'pr_level'   => 'pr_level',
3675                                         'pr_cascade' => 'pr_cascade',
3676                                         'pr_user'    => 'pr_user',
3677                                         'pr_expiry'  => 'pr_expiry'
3678                                 ),
3679                                 array( 'pr_page' => $pageid ),
3680                                 __METHOD__,
3681                                 array( 'IGNORE' )
3682                         );
3683                         # Update the protection log
3684                         $log = new LogPage( 'protect' );
3685                         $comment = wfMessage(
3686                                 'prot_1movedto2',
3687                                 $this->getPrefixedText(),
3688                                 $nt->getPrefixedText()
3689                         )->inContentLanguage()->text();
3690                         if ( $reason ) {
3691                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3692                         }
3693                         // @todo FIXME: $params?
3694                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3695                 }
3696
3697                 # Update watchlists
3698                 $oldnamespace = $this->getNamespace() & ~1;
3699                 $newnamespace = $nt->getNamespace() & ~1;
3700                 $oldtitle = $this->getDBkey();
3701                 $newtitle = $nt->getDBkey();
3702
3703                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3704                         WatchedItem::duplicateEntries( $this, $nt );
3705                 }
3706
3707                 $dbw->commit( __METHOD__ );
3708
3709                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3710                 return true;
3711         }
3712
3713         /**
3714          * Move page to a title which is either a redirect to the
3715          * source page or nonexistent
3716          *
3717          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3718          * @param $reason String The reason for the move
3719          * @param $createRedirect Bool Whether to leave a redirect at the old title. Does not check
3720          *   if the user has the suppressredirect right
3721          * @throws MWException
3722          */
3723         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3724                 global $wgUser, $wgContLang;
3725
3726                 if ( $nt->exists() ) {
3727                         $moveOverRedirect = true;
3728                         $logType = 'move_redir';
3729                 } else {
3730                         $moveOverRedirect = false;
3731                         $logType = 'move';
3732                 }
3733
3734                 if ( $createRedirect ) {
3735                         $contentHandler = ContentHandler::getForTitle( $this );
3736                         $redirectContent = $contentHandler->makeRedirectContent( $nt );
3737
3738                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3739                 } else {
3740                         $redirectContent = null;
3741                 }
3742
3743                 $logEntry = new ManualLogEntry( 'move', $logType );
3744                 $logEntry->setPerformer( $wgUser );
3745                 $logEntry->setTarget( $this );
3746                 $logEntry->setComment( $reason );
3747                 $logEntry->setParameters( array(
3748                         '4::target' => $nt->getPrefixedText(),
3749                         '5::noredir' => $redirectContent ? '0': '1',
3750                 ) );
3751
3752                 $formatter = LogFormatter::newFromEntry( $logEntry );
3753                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3754                 $comment = $formatter->getPlainActionText();
3755                 if ( $reason ) {
3756                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3757                 }
3758                 # Truncate for whole multibyte characters.
3759                 $comment = $wgContLang->truncate( $comment, 255 );
3760
3761                 $oldid = $this->getArticleID();
3762
3763                 $dbw = wfGetDB( DB_MASTER );
3764
3765                 $newpage = WikiPage::factory( $nt );
3766
3767                 if ( $moveOverRedirect ) {
3768                         $newid = $nt->getArticleID();
3769
3770                         # Delete the old redirect. We don't save it to history since
3771                         # by definition if we've got here it's rather uninteresting.
3772                         # We have to remove it so that the next step doesn't trigger
3773                         # a conflict on the unique namespace+title index...
3774                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3775
3776                         $newpage->doDeleteUpdates( $newid );
3777                 }
3778
3779                 # Save a null revision in the page's history notifying of the move
3780                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3781                 if ( !is_object( $nullRevision ) ) {
3782                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3783                 }
3784
3785                 $nullRevision->insertOn( $dbw );
3786
3787                 # Change the name of the target page:
3788                 $dbw->update( 'page',
3789                         /* SET */ array(
3790                                 'page_namespace' => $nt->getNamespace(),
3791                                 'page_title'     => $nt->getDBkey(),
3792                         ),
3793                         /* WHERE */ array( 'page_id' => $oldid ),
3794                         __METHOD__
3795                 );
3796
3797                 $this->resetArticleID( 0 );
3798                 $nt->resetArticleID( $oldid );
3799
3800                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3801
3802                 wfRunHooks( 'NewRevisionFromEditComplete',
3803                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3804
3805                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3806
3807                 if ( !$moveOverRedirect ) {
3808                         WikiPage::onArticleCreate( $nt );
3809                 }
3810
3811                 # Recreate the redirect, this time in the other direction.
3812                 if ( !$redirectContent ) {
3813                         WikiPage::onArticleDelete( $this );
3814                 } else {
3815                         $redirectArticle = WikiPage::factory( $this );
3816                         $newid = $redirectArticle->insertOn( $dbw );
3817                         if ( $newid ) { // sanity
3818                                 $redirectRevision = new Revision( array(
3819                                         'page'    => $newid,
3820                                         'comment' => $comment,
3821                                         'content'    => $redirectContent ) );
3822                                 $redirectRevision->insertOn( $dbw );
3823                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3824
3825                                 wfRunHooks( 'NewRevisionFromEditComplete',
3826                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3827
3828                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3829                         }
3830                 }
3831
3832                 # Log the move
3833                 $logid = $logEntry->insert();
3834                 $logEntry->publish( $logid );
3835         }
3836
3837         /**
3838          * Move this page's subpages to be subpages of $nt
3839          *
3840          * @param $nt Title Move target
3841          * @param $auth bool Whether $wgUser's permissions should be checked
3842          * @param $reason string The reason for the move
3843          * @param $createRedirect bool Whether to create redirects from the old subpages to
3844          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3845          * @return mixed array with old page titles as keys, and strings (new page titles) or
3846          *     arrays (errors) as values, or an error array with numeric indices if no pages
3847          *     were moved
3848          */
3849         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3850                 global $wgMaximumMovedPages;
3851                 // Check permissions
3852                 if ( !$this->userCan( 'move-subpages' ) ) {
3853                         return array( 'cant-move-subpages' );
3854                 }
3855                 // Do the source and target namespaces support subpages?
3856                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3857                         return array( 'namespace-nosubpages',
3858                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3859                 }
3860                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3861                         return array( 'namespace-nosubpages',
3862                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3863                 }
3864
3865                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3866                 $retval = array();
3867                 $count = 0;
3868                 foreach ( $subpages as $oldSubpage ) {
3869                         $count++;
3870                         if ( $count > $wgMaximumMovedPages ) {
3871                                 $retval[$oldSubpage->getPrefixedTitle()] =
3872                                                 array( 'movepage-max-pages',
3873                                                         $wgMaximumMovedPages );
3874                                 break;
3875                         }
3876
3877                         // We don't know whether this function was called before
3878                         // or after moving the root page, so check both
3879                         // $this and $nt
3880                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3881                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3882                         {
3883                                 // When moving a page to a subpage of itself,
3884                                 // don't move it twice
3885                                 continue;
3886                         }
3887                         $newPageName = preg_replace(
3888                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3889                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3890                                         $oldSubpage->getDBkey() );
3891                         if ( $oldSubpage->isTalkPage() ) {
3892                                 $newNs = $nt->getTalkPage()->getNamespace();
3893                         } else {
3894                                 $newNs = $nt->getSubjectPage()->getNamespace();
3895                         }
3896                         # Bug 14385: we need makeTitleSafe because the new page names may
3897                         # be longer than 255 characters.
3898                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3899
3900                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3901                         if ( $success === true ) {
3902                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3903                         } else {
3904                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3905                         }
3906                 }
3907                 return $retval;
3908         }
3909
3910         /**
3911          * Checks if this page is just a one-rev redirect.
3912          * Adds lock, so don't use just for light purposes.
3913          *
3914          * @return Bool
3915          */
3916         public function isSingleRevRedirect() {
3917                 global $wgContentHandlerUseDB;
3918
3919                 $dbw = wfGetDB( DB_MASTER );
3920
3921                 # Is it a redirect?
3922                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3923                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3924
3925                 $row = $dbw->selectRow( 'page',
3926                         $fields,
3927                         $this->pageCond(),
3928                         __METHOD__,
3929                         array( 'FOR UPDATE' )
3930                 );
3931                 # Cache some fields we may want
3932                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3933                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3934                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3935                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
3936                 if ( !$this->mRedirect ) {
3937                         return false;
3938                 }
3939                 # Does the article have a history?
3940                 $row = $dbw->selectField( array( 'page', 'revision' ),
3941                         'rev_id',
3942                         array( 'page_namespace' => $this->getNamespace(),
3943                                 'page_title' => $this->getDBkey(),
3944                                 'page_id=rev_page',
3945                                 'page_latest != rev_id'
3946                         ),
3947                         __METHOD__,
3948                         array( 'FOR UPDATE' )
3949                 );
3950                 # Return true if there was no history
3951                 return ( $row === false );
3952         }
3953
3954         /**
3955          * Checks if $this can be moved to a given Title
3956          * - Selects for update, so don't call it unless you mean business
3957          *
3958          * @param $nt Title the new title to check
3959          * @return Bool
3960          */
3961         public function isValidMoveTarget( $nt ) {
3962                 # Is it an existing file?
3963                 if ( $nt->getNamespace() == NS_FILE ) {
3964                         $file = wfLocalFile( $nt );
3965                         if ( $file->exists() ) {
3966                                 wfDebug( __METHOD__ . ": file exists\n" );
3967                                 return false;
3968                         }
3969                 }
3970                 # Is it a redirect with no history?
3971                 if ( !$nt->isSingleRevRedirect() ) {
3972                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3973                         return false;
3974                 }
3975                 # Get the article text
3976                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3977                 if( !is_object( $rev ) ){
3978                         return false;
3979                 }
3980                 $content = $rev->getContent();
3981                 # Does the redirect point to the source?
3982                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3983                 $redirTitle = $content->getRedirectTarget();
3984
3985                 if ( $redirTitle ) {
3986                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3987                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3988                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3989                                 return false;
3990                         } else {
3991                                 return true;
3992                         }
3993                 } else {
3994                         # Fail safe (not a redirect after all. strange.)
3995                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3996                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3997                         return false;
3998                 }
3999         }
4000
4001         /**
4002          * Get categories to which this Title belongs and return an array of
4003          * categories' names.
4004          *
4005          * @return Array of parents in the form:
4006          *        $parent => $currentarticle
4007          */
4008         public function getParentCategories() {
4009                 global $wgContLang;
4010
4011                 $data = array();
4012
4013                 $titleKey = $this->getArticleID();
4014
4015                 if ( $titleKey === 0 ) {
4016                         return $data;
4017                 }
4018
4019                 $dbr = wfGetDB( DB_SLAVE );
4020
4021                 $res = $dbr->select( 'categorylinks', '*',
4022                         array(
4023                                 'cl_from' => $titleKey,
4024                         ),
4025                         __METHOD__,
4026                         array()
4027                 );
4028
4029                 if ( $dbr->numRows( $res ) > 0 ) {
4030                         foreach ( $res as $row ) {
4031                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
4032                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4033                         }
4034                 }
4035                 return $data;
4036         }
4037
4038         /**
4039          * Get a tree of parent categories
4040          *
4041          * @param $children Array with the children in the keys, to check for circular refs
4042          * @return Array Tree of parent categories
4043          */
4044         public function getParentCategoryTree( $children = array() ) {
4045                 $stack = array();
4046                 $parents = $this->getParentCategories();
4047
4048                 if ( $parents ) {
4049                         foreach ( $parents as $parent => $current ) {
4050                                 if ( array_key_exists( $parent, $children ) ) {
4051                                         # Circular reference
4052                                         $stack[$parent] = array();
4053                                 } else {
4054                                         $nt = Title::newFromText( $parent );
4055                                         if ( $nt ) {
4056                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4057                                         }
4058                                 }
4059                         }
4060                 }
4061
4062                 return $stack;
4063         }
4064
4065         /**
4066          * Get an associative array for selecting this title from
4067          * the "page" table
4068          *
4069          * @return Array suitable for the $where parameter of DB::select()
4070          */
4071         public function pageCond() {
4072                 if ( $this->mArticleID > 0 ) {
4073                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4074                         return array( 'page_id' => $this->mArticleID );
4075                 } else {
4076                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4077                 }
4078         }
4079
4080         /**
4081          * Get the revision ID of the previous revision
4082          *
4083          * @param $revId Int Revision ID. Get the revision that was before this one.
4084          * @param $flags Int Title::GAID_FOR_UPDATE
4085          * @return Int|Bool Old revision ID, or FALSE if none exists
4086          */
4087         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4088                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4089                 $revId = $db->selectField( 'revision', 'rev_id',
4090                         array(
4091                                 'rev_page' => $this->getArticleID( $flags ),
4092                                 'rev_id < ' . intval( $revId )
4093                         ),
4094                         __METHOD__,
4095                         array( 'ORDER BY' => 'rev_id DESC' )
4096                 );
4097
4098                 if ( $revId === false ) {
4099                         return false;
4100                 } else {
4101                         return intval( $revId );
4102                 }
4103         }
4104
4105         /**
4106          * Get the revision ID of the next revision
4107          *
4108          * @param $revId Int Revision ID. Get the revision that was after this one.
4109          * @param $flags Int Title::GAID_FOR_UPDATE
4110          * @return Int|Bool Next revision ID, or FALSE if none exists
4111          */
4112         public function getNextRevisionID( $revId, $flags = 0 ) {
4113                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4114                 $revId = $db->selectField( 'revision', 'rev_id',
4115                         array(
4116                                 'rev_page' => $this->getArticleID( $flags ),
4117                                 'rev_id > ' . intval( $revId )
4118                         ),
4119                         __METHOD__,
4120                         array( 'ORDER BY' => 'rev_id' )
4121                 );
4122
4123                 if ( $revId === false ) {
4124                         return false;
4125                 } else {
4126                         return intval( $revId );
4127                 }
4128         }
4129
4130         /**
4131          * Get the first revision of the page
4132          *
4133          * @param $flags Int Title::GAID_FOR_UPDATE
4134          * @return Revision|Null if page doesn't exist
4135          */
4136         public function getFirstRevision( $flags = 0 ) {
4137                 $pageId = $this->getArticleID( $flags );
4138                 if ( $pageId ) {
4139                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4140                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4141                                 array( 'rev_page' => $pageId ),
4142                                 __METHOD__,
4143                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4144                         );
4145                         if ( $row ) {
4146                                 return new Revision( $row );
4147                         }
4148                 }
4149                 return null;
4150         }
4151
4152         /**
4153          * Get the oldest revision timestamp of this page
4154          *
4155          * @param $flags Int Title::GAID_FOR_UPDATE
4156          * @return String: MW timestamp
4157          */
4158         public function getEarliestRevTime( $flags = 0 ) {
4159                 $rev = $this->getFirstRevision( $flags );
4160                 return $rev ? $rev->getTimestamp() : null;
4161         }
4162
4163         /**
4164          * Check if this is a new page
4165          *
4166          * @return bool
4167          */
4168         public function isNewPage() {
4169                 $dbr = wfGetDB( DB_SLAVE );
4170                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4171         }
4172
4173         /**
4174          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4175          *
4176          * @return bool
4177          */
4178         public function isBigDeletion() {
4179                 global $wgDeleteRevisionsLimit;
4180
4181                 if ( !$wgDeleteRevisionsLimit ) {
4182                         return false;
4183                 }
4184
4185                 $revCount = $this->estimateRevisionCount();
4186                 return $revCount > $wgDeleteRevisionsLimit;
4187         }
4188
4189         /**
4190          * Get the  approximate revision count of this page.
4191          *
4192          * @return int
4193          */
4194         public function estimateRevisionCount() {
4195                 if ( !$this->exists() ) {
4196                         return 0;
4197                 }
4198
4199                 if ( $this->mEstimateRevisions === null ) {
4200                         $dbr = wfGetDB( DB_SLAVE );
4201                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4202                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4203                 }
4204
4205                 return $this->mEstimateRevisions;
4206         }
4207
4208         /**
4209          * Get the number of revisions between the given revision.
4210          * Used for diffs and other things that really need it.
4211          *
4212          * @param $old int|Revision Old revision or rev ID (first before range)
4213          * @param $new int|Revision New revision or rev ID (first after range)
4214          * @return Int Number of revisions between these revisions.
4215          */
4216         public function countRevisionsBetween( $old, $new ) {
4217                 if ( !( $old instanceof Revision ) ) {
4218                         $old = Revision::newFromTitle( $this, (int)$old );
4219                 }
4220                 if ( !( $new instanceof Revision ) ) {
4221                         $new = Revision::newFromTitle( $this, (int)$new );
4222                 }
4223                 if ( !$old || !$new ) {
4224                         return 0; // nothing to compare
4225                 }
4226                 $dbr = wfGetDB( DB_SLAVE );
4227                 return (int)$dbr->selectField( 'revision', 'count(*)',
4228                         array(
4229                                 'rev_page' => $this->getArticleID(),
4230                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4231                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4232                         ),
4233                         __METHOD__
4234                 );
4235         }
4236
4237         /**
4238          * Get the number of authors between the given revisions or revision IDs.
4239          * Used for diffs and other things that really need it.
4240          *
4241          * @param $old int|Revision Old revision or rev ID (first before range by default)
4242          * @param $new int|Revision New revision or rev ID (first after range by default)
4243          * @param $limit int Maximum number of authors
4244          * @param $options string|array (Optional): Single option, or an array of options:
4245          *     'include_old' Include $old in the range; $new is excluded.
4246          *     'include_new' Include $new in the range; $old is excluded.
4247          *     'include_both' Include both $old and $new in the range.
4248          *     Unknown option values are ignored.
4249          * @return int Number of revision authors in the range; zero if not both revisions exist
4250          */
4251         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4252                 if ( !( $old instanceof Revision ) ) {
4253                         $old = Revision::newFromTitle( $this, (int)$old );
4254                 }
4255                 if ( !( $new instanceof Revision ) ) {
4256                         $new = Revision::newFromTitle( $this, (int)$new );
4257                 }
4258                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4259                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4260                 // in the sanity check below?
4261                 if ( !$old || !$new ) {
4262                         return 0; // nothing to compare
4263                 }
4264                 $old_cmp = '>';
4265                 $new_cmp = '<';
4266                 $options = (array) $options;
4267                 if ( in_array( 'include_old', $options ) ) {
4268                         $old_cmp = '>=';
4269                 }
4270                 if ( in_array( 'include_new', $options ) ) {
4271                         $new_cmp = '<=';
4272                 }
4273                 if ( in_array( 'include_both', $options ) ) {
4274                         $old_cmp = '>=';
4275                         $new_cmp = '<=';
4276                 }
4277                 // No DB query needed if $old and $new are the same or successive revisions:
4278                 if ( $old->getId() === $new->getId() ) {
4279                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4280                 } else if ( $old->getId() === $new->getParentId() ) {
4281                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4282                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4283                         }
4284                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4285                 }
4286                 $dbr = wfGetDB( DB_SLAVE );
4287                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4288                         array(
4289                                 'rev_page' => $this->getArticleID(),
4290                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4291                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4292                         ), __METHOD__,
4293                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4294                 );
4295                 return (int)$dbr->numRows( $res );
4296         }
4297
4298         /**
4299          * Compare with another title.
4300          *
4301          * @param $title Title
4302          * @return Bool
4303          */
4304         public function equals( Title $title ) {
4305                 // Note: === is necessary for proper matching of number-like titles.
4306                 return $this->getInterwiki() === $title->getInterwiki()
4307                         && $this->getNamespace() == $title->getNamespace()
4308                         && $this->getDBkey() === $title->getDBkey();
4309         }
4310
4311         /**
4312          * Check if this title is a subpage of another title
4313          *
4314          * @param $title Title
4315          * @return Bool
4316          */
4317         public function isSubpageOf( Title $title ) {
4318                 return $this->getInterwiki() === $title->getInterwiki()
4319                         && $this->getNamespace() == $title->getNamespace()
4320                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4321         }
4322
4323         /**
4324          * Check if page exists.  For historical reasons, this function simply
4325          * checks for the existence of the title in the page table, and will
4326          * thus return false for interwiki links, special pages and the like.
4327          * If you want to know if a title can be meaningfully viewed, you should
4328          * probably call the isKnown() method instead.
4329          *
4330          * @return Bool
4331          */
4332         public function exists() {
4333                 return $this->getArticleID() != 0;
4334         }
4335
4336         /**
4337          * Should links to this title be shown as potentially viewable (i.e. as
4338          * "bluelinks"), even if there's no record by this title in the page
4339          * table?
4340          *
4341          * This function is semi-deprecated for public use, as well as somewhat
4342          * misleadingly named.  You probably just want to call isKnown(), which
4343          * calls this function internally.
4344          *
4345          * (ISSUE: Most of these checks are cheap, but the file existence check
4346          * can potentially be quite expensive.  Including it here fixes a lot of
4347          * existing code, but we might want to add an optional parameter to skip
4348          * it and any other expensive checks.)
4349          *
4350          * @return Bool
4351          */
4352         public function isAlwaysKnown() {
4353                 $isKnown = null;
4354
4355                 /**
4356                  * Allows overriding default behaviour for determining if a page exists.
4357                  * If $isKnown is kept as null, regular checks happen. If it's
4358                  * a boolean, this value is returned by the isKnown method.
4359                  *
4360                  * @since 1.20
4361                  *
4362                  * @param Title $title
4363                  * @param boolean|null $isKnown
4364                  */
4365                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4366
4367                 if ( !is_null( $isKnown ) ) {
4368                         return $isKnown;
4369                 }
4370
4371                 if ( $this->mInterwiki != '' ) {
4372                         return true;  // any interwiki link might be viewable, for all we know
4373                 }
4374
4375                 switch( $this->mNamespace ) {
4376                         case NS_MEDIA:
4377                         case NS_FILE:
4378                                 // file exists, possibly in a foreign repo
4379                                 return (bool)wfFindFile( $this );
4380                         case NS_SPECIAL:
4381                                 // valid special page
4382                                 return SpecialPageFactory::exists( $this->getDBkey() );
4383                         case NS_MAIN:
4384                                 // selflink, possibly with fragment
4385                                 return $this->mDbkeyform == '';
4386                         case NS_MEDIAWIKI:
4387                                 // known system message
4388                                 return $this->hasSourceText() !== false;
4389                         default:
4390                                 return false;
4391                 }
4392         }
4393
4394         /**
4395          * Does this title refer to a page that can (or might) be meaningfully
4396          * viewed?  In particular, this function may be used to determine if
4397          * links to the title should be rendered as "bluelinks" (as opposed to
4398          * "redlinks" to non-existent pages).
4399          * Adding something else to this function will cause inconsistency
4400          * since LinkHolderArray calls isAlwaysKnown() and does its own
4401          * page existence check.
4402          *
4403          * @return Bool
4404          */
4405         public function isKnown() {
4406                 return $this->isAlwaysKnown() || $this->exists();
4407         }
4408
4409         /**
4410          * Does this page have source text?
4411          *
4412          * @return Boolean
4413          */
4414         public function hasSourceText() {
4415                 if ( $this->exists() ) {
4416                         return true;
4417                 }
4418
4419                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4420                         // If the page doesn't exist but is a known system message, default
4421                         // message content will be displayed, same for language subpages-
4422                         // Use always content language to avoid loading hundreds of languages
4423                         // to get the link color.
4424                         global $wgContLang;
4425                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4426                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4427                         return $message->exists();
4428                 }
4429
4430                 return false;
4431         }
4432
4433         /**
4434          * Get the default message text or false if the message doesn't exist
4435          *
4436          * @return String or false
4437          */
4438         public function getDefaultMessageText() {
4439                 global $wgContLang;
4440
4441                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4442                         return false;
4443                 }
4444
4445                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4446                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4447
4448                 if ( $message->exists() ) {
4449                         return $message->plain();
4450                 } else {
4451                         return false;
4452                 }
4453         }
4454
4455         /**
4456          * Updates page_touched for this page; called from LinksUpdate.php
4457          *
4458          * @return Bool true if the update succeded
4459          */
4460         public function invalidateCache() {
4461                 if ( wfReadOnly() ) {
4462                         return false;
4463                 }
4464                 $dbw = wfGetDB( DB_MASTER );
4465                 $success = $dbw->update(
4466                         'page',
4467                         array( 'page_touched' => $dbw->timestamp() ),
4468                         $this->pageCond(),
4469                         __METHOD__
4470                 );
4471                 HTMLFileCache::clearFileCache( $this );
4472                 return $success;
4473         }
4474
4475         /**
4476          * Update page_touched timestamps and send squid purge messages for
4477          * pages linking to this title. May be sent to the job queue depending
4478          * on the number of links. Typically called on create and delete.
4479          */
4480         public function touchLinks() {
4481                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4482                 $u->doUpdate();
4483
4484                 if ( $this->getNamespace() == NS_CATEGORY ) {
4485                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4486                         $u->doUpdate();
4487                 }
4488         }
4489
4490         /**
4491          * Get the last touched timestamp
4492          *
4493          * @param $db DatabaseBase: optional db
4494          * @return String last-touched timestamp
4495          */
4496         public function getTouched( $db = null ) {
4497                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4498                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4499                 return $touched;
4500         }
4501
4502         /**
4503          * Get the timestamp when this page was updated since the user last saw it.
4504          *
4505          * @param $user User
4506          * @return String|Null
4507          */
4508         public function getNotificationTimestamp( $user = null ) {
4509                 global $wgUser, $wgShowUpdatedMarker;
4510                 // Assume current user if none given
4511                 if ( !$user ) {
4512                         $user = $wgUser;
4513                 }
4514                 // Check cache first
4515                 $uid = $user->getId();
4516                 // avoid isset here, as it'll return false for null entries
4517                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4518                         return $this->mNotificationTimestamp[$uid];
4519                 }
4520                 if ( !$uid || !$wgShowUpdatedMarker ) {
4521                         return $this->mNotificationTimestamp[$uid] = false;
4522                 }
4523                 // Don't cache too much!
4524                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4525                         $this->mNotificationTimestamp = array();
4526                 }
4527                 $dbr = wfGetDB( DB_SLAVE );
4528                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4529                         'wl_notificationtimestamp',
4530                         array(
4531                                 'wl_user' => $user->getId(),
4532                                 'wl_namespace' => $this->getNamespace(),
4533                                 'wl_title' => $this->getDBkey(),
4534                         ),
4535                         __METHOD__
4536                 );
4537                 return $this->mNotificationTimestamp[$uid];
4538         }
4539
4540         /**
4541          * Generate strings used for xml 'id' names in monobook tabs
4542          *
4543          * @param $prepend string defaults to 'nstab-'
4544          * @return String XML 'id' name
4545          */
4546         public function getNamespaceKey( $prepend = 'nstab-' ) {
4547                 global $wgContLang;
4548                 // Gets the subject namespace if this title
4549                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4550                 // Checks if cononical namespace name exists for namespace
4551                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4552                         // Uses canonical namespace name
4553                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4554                 } else {
4555                         // Uses text of namespace
4556                         $namespaceKey = $this->getSubjectNsText();
4557                 }
4558                 // Makes namespace key lowercase
4559                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4560                 // Uses main
4561                 if ( $namespaceKey == '' ) {
4562                         $namespaceKey = 'main';
4563                 }
4564                 // Changes file to image for backwards compatibility
4565                 if ( $namespaceKey == 'file' ) {
4566                         $namespaceKey = 'image';
4567                 }
4568                 return $prepend . $namespaceKey;
4569         }
4570
4571         /**
4572          * Get all extant redirects to this Title
4573          *
4574          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4575          * @return Array of Title redirects to this title
4576          */
4577         public function getRedirectsHere( $ns = null ) {
4578                 $redirs = array();
4579
4580                 $dbr = wfGetDB( DB_SLAVE );
4581                 $where = array(
4582                         'rd_namespace' => $this->getNamespace(),
4583                         'rd_title' => $this->getDBkey(),
4584                         'rd_from = page_id'
4585                 );
4586                 if ( $this->isExternal() ) {
4587                         $where['rd_interwiki'] = $this->getInterwiki();
4588                 } else {
4589                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4590                 }
4591                 if ( !is_null( $ns ) ) {
4592                         $where['page_namespace'] = $ns;
4593                 }
4594
4595                 $res = $dbr->select(
4596                         array( 'redirect', 'page' ),
4597                         array( 'page_namespace', 'page_title' ),
4598                         $where,
4599                         __METHOD__
4600                 );
4601
4602                 foreach ( $res as $row ) {
4603                         $redirs[] = self::newFromRow( $row );
4604                 }
4605                 return $redirs;
4606         }
4607
4608         /**
4609          * Check if this Title is a valid redirect target
4610          *
4611          * @return Bool
4612          */
4613         public function isValidRedirectTarget() {
4614                 global $wgInvalidRedirectTargets;
4615
4616                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4617                 if ( $this->isSpecial( 'Userlogout' ) ) {
4618                         return false;
4619                 }
4620
4621                 foreach ( $wgInvalidRedirectTargets as $target ) {
4622                         if ( $this->isSpecial( $target ) ) {
4623                                 return false;
4624                         }
4625                 }
4626
4627                 return true;
4628         }
4629
4630         /**
4631          * Get a backlink cache object
4632          *
4633          * @return BacklinkCache
4634          */
4635         public function getBacklinkCache() {
4636                 return BacklinkCache::get( $this );
4637         }
4638
4639         /**
4640          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4641          *
4642          * @return Boolean
4643          */
4644         public function canUseNoindex() {
4645                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4646
4647                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4648                         ? $wgContentNamespaces
4649                         : $wgExemptFromUserRobotsControl;
4650
4651                 return !in_array( $this->mNamespace, $bannedNamespaces );
4652
4653         }
4654
4655         /**
4656          * Returns the raw sort key to be used for categories, with the specified
4657          * prefix.  This will be fed to Collation::getSortKey() to get a
4658          * binary sortkey that can be used for actual sorting.
4659          *
4660          * @param $prefix string The prefix to be used, specified using
4661          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4662          *   prefix.
4663          * @return string
4664          */
4665         public function getCategorySortkey( $prefix = '' ) {
4666                 $unprefixed = $this->getText();
4667
4668                 // Anything that uses this hook should only depend
4669                 // on the Title object passed in, and should probably
4670                 // tell the users to run updateCollations.php --force
4671                 // in order to re-sort existing category relations.
4672                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4673                 if ( $prefix !== '' ) {
4674                         # Separate with a line feed, so the unprefixed part is only used as
4675                         # a tiebreaker when two pages have the exact same prefix.
4676                         # In UCA, tab is the only character that can sort above LF
4677                         # so we strip both of them from the original prefix.
4678                         $prefix = strtr( $prefix, "\n\t", '  ' );
4679                         return "$prefix\n$unprefixed";
4680                 }
4681                 return $unprefixed;
4682         }
4683
4684         /**
4685          * Get the language in which the content of this page is written in
4686          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4687          * e.g. $wgLang (such as special pages, which are in the user language).
4688          *
4689          * @since 1.18
4690          * @return Language
4691          */
4692         public function getPageLanguage() {
4693                 global $wgLang;
4694                 if ( $this->isSpecialPage() ) {
4695                         // special pages are in the user language
4696                         return $wgLang;
4697                 }
4698
4699                 //TODO: use the LinkCache to cache this! Note that this may depend on user settings, so the cache should be only per-request.
4700                 //NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4701                 $contentHandler = ContentHandler::getForTitle( $this );
4702                 $pageLang = $contentHandler->getPageLanguage( $this );
4703
4704                 // Hook at the end because we don't want to override the above stuff
4705                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4706                 return wfGetLangObj( $pageLang );
4707         }
4708
4709         /**
4710          * Get the language in which the content of this page is written when
4711          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4712          * e.g. $wgLang (such as special pages, which are in the user language).
4713          *
4714          * @since 1.20
4715          * @return Language
4716          */
4717         public function getPageViewLanguage() {
4718                 global $wgLang;
4719
4720                 if ( $this->isSpecialPage() ) {
4721                         // If the user chooses a variant, the content is actually
4722                         // in a language whose code is the variant code.
4723                         $variant = $wgLang->getPreferredVariant();
4724                         if ( $wgLang->getCode() !== $variant ) {
4725                                 return Language::factory( $variant );
4726                         }
4727
4728                         return $wgLang;
4729                 }
4730
4731                 //NOTE: can't be cached persistently, depends on user settings
4732                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4733                 $contentHandler = ContentHandler::getForTitle( $this );
4734                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4735                 return $pageLang;
4736         }
4737 }