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          * Constructor
  93          */
  94         /*protected*/ function __construct() { }
  95
  96         /**
  97          * Create a new Title from a prefixed DB key
  98          *
  99          * @param string $key the database key, which has underscores
 100          *      instead of spaces, possibly including namespace and
 101          *      interwiki prefixes
 102          * @return Title, or NULL on an error
 103          */
 104         public static function newFromDBkey( $key ) {
 105                 $t = new Title();
 106                 $t->mDbkeyform = $key;
 107                 if ( $t->secureAndSplit() ) {
 108                         return $t;
 109                 } else {
 110                         return null;
 111                 }
 112         }
 113
 114         /**
 115          * Create a new Title from text, such as what one would find in a link. De-
 116          * codes any HTML entities in the text.
 117          *
 118          * @param string $text the link text; spaces, prefixes, and an
 119          *   initial ':' indicating the main namespace are accepted.
 120          * @param int $defaultNamespace the namespace to use if none is specified
 121          *   by a prefix.  If you want to force a specific namespace even if
 122          *   $text might begin with a namespace prefix, use makeTitle() or
 123          *   makeTitleSafe().
 124          * @throws MWException
 125          * @return Title|null - Title or null on an error.
 126          */
 127         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 128                 if ( is_object( $text ) ) {
 129                         throw new MWException( 'Title::newFromText given an object' );
 130                 }
 131
 132                 /**
 133                  * Wiki pages often contain multiple links to the same page.
 134                  * Title normalization and parsing can become expensive on
 135                  * pages with many links, so we can save a little time by
 136                  * caching them.
 137                  *
 138                  * In theory these are value objects and won't get changed...
 139                  */
 140                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 141                         return Title::$titleCache[$text];
 142                 }
 143
 144                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 145                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 146
 147                 $t = new Title();
 148                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 149                 $t->mDefaultNamespace = $defaultNamespace;
 150
 151                 static $cachedcount = 0;
 152                 if ( $t->secureAndSplit() ) {
 153                         if ( $defaultNamespace == NS_MAIN ) {
 154                                 if ( $cachedcount >= self::CACHE_MAX ) {
 155                                         # Avoid memory leaks on mass operations...
 156                                         Title::$titleCache = array();
 157                                         $cachedcount = 0;
 158                                 }
 159                                 $cachedcount++;
 160                                 Title::$titleCache[$text] =& $t;
 161                         }
 162                         return $t;
 163                 } else {
 164                         $ret = null;
 165                         return $ret;
 166                 }
 167         }
 168
 169         /**
 170          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 171          *
 172          * Example of wrong and broken code:
 173          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Example of right code:
 176          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 177          *
 178          * Create a new Title from URL-encoded text. Ensures that
 179          * the given title's length does not exceed the maximum.
 180          *
 181          * @param string $url the title, as might be taken from a URL
 182          * @return Title the new object, or NULL on an error
 183          */
 184         public static function newFromURL( $url ) {
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( self::legalChars(), '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 204          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 205          *
 206          * @return array
 207          */
 208         protected static function getSelectFields() {
 209                 global $wgContentHandlerUseDB;
 210
 211                 $fields = array(
 212                         'page_namespace', 'page_title', 'page_id',
 213                         'page_len', 'page_is_redirect', 'page_latest',
 214                 );
 215
 216                 if ( $wgContentHandlerUseDB ) {
 217                         $fields[] = 'page_content_model';
 218                 }
 219
 220                 return $fields;
 221         }
 222
 223         /**
 224          * Create a new Title from an article ID
 225          *
 226          * @param int $id the page_id corresponding to the Title to create
 227          * @param int $flags use Title::GAID_FOR_UPDATE to use master
 228          * @return Title the new object, or NULL on an error
 229          */
 230         public static function newFromID( $id, $flags = 0 ) {
 231                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 232                 $row = $db->selectRow(
 233                         'page',
 234                         self::getSelectFields(),
 235                         array( 'page_id' => $id ),
 236                         __METHOD__
 237                 );
 238                 if ( $row !== false ) {
 239                         $title = Title::newFromRow( $row );
 240                 } else {
 241                         $title = null;
 242                 }
 243                 return $title;
 244         }
 245
 246         /**
 247          * Make an array of titles from an array of IDs
 248          *
 249          * @param array $ids of Int Array of IDs
 250          * @return Array of Titles
 251          */
 252         public static function newFromIDs( $ids ) {
 253                 if ( !count( $ids ) ) {
 254                         return array();
 255                 }
 256                 $dbr = wfGetDB( DB_SLAVE );
 257
 258                 $res = $dbr->select(
 259                         'page',
 260                         self::getSelectFields(),
 261                         array( 'page_id' => $ids ),
 262                         __METHOD__
 263                 );
 264
 265                 $titles = array();
 266                 foreach ( $res as $row ) {
 267                         $titles[] = Title::newFromRow( $row );
 268                 }
 269                 return $titles;
 270         }
 271
 272         /**
 273          * Make a Title object from a DB row
 274          *
 275          * @param $row Object database row (needs at least page_title,page_namespace)
 276          * @return Title corresponding Title
 277          */
 278         public static function newFromRow( $row ) {
 279                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 280                 $t->loadFromRow( $row );
 281                 return $t;
 282         }
 283
 284         /**
 285          * Load Title object fields from a DB row.
 286          * If false is given, the title will be treated as non-existing.
 287          *
 288          * @param $row Object|bool database row
 289          */
 290         public function loadFromRow( $row ) {
 291                 if ( $row ) { // page found
 292                         if ( isset( $row->page_id ) ) {
 293                                 $this->mArticleID = (int)$row->page_id;
 294                         }
 295                         if ( isset( $row->page_len ) ) {
 296                                 $this->mLength = (int)$row->page_len;
 297                         }
 298                         if ( isset( $row->page_is_redirect ) ) {
 299                                 $this->mRedirect = (bool)$row->page_is_redirect;
 300                         }
 301                         if ( isset( $row->page_latest ) ) {
 302                                 $this->mLatestID = (int)$row->page_latest;
 303                         }
 304                         if ( isset( $row->page_content_model ) ) {
 305                                 $this->mContentModel = strval( $row->page_content_model );
 306                         } else {
 307                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 308                         }
 309                 } else { // page not found
 310                         $this->mArticleID = 0;
 311                         $this->mLength = 0;
 312                         $this->mRedirect = false;
 313                         $this->mLatestID = 0;
 314                         $this->mContentModel = false; # initialized lazily in getContentModel()
 315                 }
 316         }
 317
 318         /**
 319          * Create a new Title from a namespace index and a DB key.
 320          * It's assumed that $ns and $title are *valid*, for instance when
 321          * they came directly from the database or a special page name.
 322          * For convenience, spaces are converted to underscores so that
 323          * eg user_text fields can be used directly.
 324          *
 325          * @param int $ns the namespace of the article
 326          * @param string $title the unprefixed database key form
 327          * @param string $fragment the link fragment (after the "#")
 328          * @param string $interwiki the interwiki prefix
 329          * @return Title the new object
 330          */
 331         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 332                 $t = new Title();
 333                 $t->mInterwiki = $interwiki;
 334                 $t->mFragment = $fragment;
 335                 $t->mNamespace = $ns = intval( $ns );
 336                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 337                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 338                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 339                 $t->mTextform = str_replace( '_', ' ', $title );
 340                 $t->mContentModel = false; # initialized lazily in getContentModel()
 341                 return $t;
 342         }
 343
 344         /**
 345          * Create a new Title from a namespace index and a DB key.
 346          * The parameters will be checked for validity, which is a bit slower
 347          * than makeTitle() but safer for user-provided data.
 348          *
 349          * @param int $ns the namespace of the article
 350          * @param string $title database key form
 351          * @param string $fragment the link fragment (after the "#")
 352          * @param string $interwiki interwiki prefix
 353          * @return Title the new object, or NULL on an error
 354          */
 355         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 356                 if ( !MWNamespace::exists( $ns ) ) {
 357                         return null;
 358                 }
 359
 360                 $t = new Title();
 361                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 362                 if ( $t->secureAndSplit() ) {
 363                         return $t;
 364                 } else {
 365                         return null;
 366                 }
 367         }
 368
 369         /**
 370          * Create a new Title for the Main Page
 371          *
 372          * @return Title the new object
 373          */
 374         public static function newMainPage() {
 375                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 376                 // Don't give fatal errors if the message is broken
 377                 if ( !$title ) {
 378                         $title = Title::newFromText( 'Main Page' );
 379                 }
 380                 return $title;
 381         }
 382
 383         /**
 384          * Extract a redirect destination from a string and return the
 385          * Title, or null if the text doesn't contain a valid redirect
 386          * This will only return the very next target, useful for
 387          * the redirect table and other checks that don't need full recursion
 388          *
 389          * @param string $text Text with possible redirect
 390          * @return Title: The corresponding Title
 391          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 392          */
 393         public static function newFromRedirect( $text ) {
 394                 ContentHandler::deprecated( __METHOD__, '1.21' );
 395
 396                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 397                 return $content->getRedirectTarget();
 398         }
 399
 400         /**
 401          * Extract a redirect destination from a string and return the
 402          * Title, or null if the text doesn't contain a valid redirect
 403          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 404          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 405          *
 406          * @param string $text Text with possible redirect
 407          * @return Title
 408          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 409          */
 410         public static function newFromRedirectRecurse( $text ) {
 411                 ContentHandler::deprecated( __METHOD__, '1.21' );
 412
 413                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 414                 return $content->getUltimateRedirectTarget();
 415         }
 416
 417         /**
 418          * Extract a redirect destination from a string and return an
 419          * array of Titles, or null if the text doesn't contain a valid redirect
 420          * The last element in the array is the final destination after all redirects
 421          * have been resolved (up to $wgMaxRedirects times)
 422          *
 423          * @param string $text Text with possible redirect
 424          * @return Array of Titles, with the destination last
 425          * @deprecated since 1.21, use Content::getRedirectChain instead.
 426          */
 427         public static function newFromRedirectArray( $text ) {
 428                 ContentHandler::deprecated( __METHOD__, '1.21' );
 429
 430                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 431                 return $content->getRedirectChain();
 432         }
 433
 434         /**
 435          * Get the prefixed DB key associated with an ID
 436          *
 437          * @param int $id the page_id of the article
 438          * @return Title an object representing the article, or NULL if no such article was found
 439          */
 440         public static function nameOf( $id ) {
 441                 $dbr = wfGetDB( DB_SLAVE );
 442
 443                 $s = $dbr->selectRow(
 444                         'page',
 445                         array( 'page_namespace', 'page_title' ),
 446                         array( 'page_id' => $id ),
 447                         __METHOD__
 448                 );
 449                 if ( $s === false ) {
 450                         return null;
 451                 }
 452
 453                 $n = self::makeName( $s->page_namespace, $s->page_title );
 454                 return $n;
 455         }
 456
 457         /**
 458          * Get a regex character class describing the legal characters in a link
 459          *
 460          * @return String the list of characters, not delimited
 461          */
 462         public static function legalChars() {
 463                 global $wgLegalTitleChars;
 464                 return $wgLegalTitleChars;
 465         }
 466
 467         /**
 468          * Returns a simple regex that will match on characters and sequences invalid in titles.
 469          * Note that this doesn't pick up many things that could be wrong with titles, but that
 470          * replacing this regex with something valid will make many titles valid.
 471          *
 472          * @return String regex string
 473          */
 474         static function getTitleInvalidRegex() {
 475                 static $rxTc = false;
 476                 if ( !$rxTc ) {
 477                         # Matching titles will be held as illegal.
 478                         $rxTc = '/' .
 479                                 # Any character not allowed is forbidden...
 480                                 '[^' . self::legalChars() . ']' .
 481                                 # URL percent encoding sequences interfere with the ability
 482                                 # to round-trip titles -- you can't link to them consistently.
 483                                 '|%[0-9A-Fa-f]{2}' .
 484                                 # XML/HTML character references produce similar issues.
 485                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 486                                 '|&#[0-9]+;' .
 487                                 '|&#x[0-9A-Fa-f]+;' .
 488                                 '/S';
 489                 }
 490
 491                 return $rxTc;
 492         }
 493
 494         /**
 495          * Get a string representation of a title suitable for
 496          * including in a search index
 497          *
 498          * @param int $ns a namespace index
 499          * @param string $title text-form main part
 500          * @return String a stripped-down title string ready for the search index
 501          */
 502         public static function indexTitle( $ns, $title ) {
 503                 global $wgContLang;
 504
 505                 $lc = SearchEngine::legalSearchChars() . '&#;';
 506                 $t = $wgContLang->normalizeForSearch( $title );
 507                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 508                 $t = $wgContLang->lc( $t );
 509
 510                 # Handle 's, s'
 511                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 512                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 513
 514                 $t = preg_replace( "/\\s+/", ' ', $t );
 515
 516                 if ( $ns == NS_FILE ) {
 517                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 518                 }
 519                 return trim( $t );
 520         }
 521
 522         /**
 523          * Make a prefixed DB key from a DB key and a namespace index
 524          *
 525          * @param int $ns numerical representation of the namespace
 526          * @param string $title the DB key form the title
 527          * @param string $fragment The link fragment (after the "#")
 528          * @param string $interwiki The interwiki prefix
 529          * @return String the prefixed form of the title
 530          */
 531         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 532                 global $wgContLang;
 533
 534                 $namespace = $wgContLang->getNsText( $ns );
 535                 $name = $namespace == '' ? $title : "$namespace:$title";
 536                 if ( strval( $interwiki ) != '' ) {
 537                         $name = "$interwiki:$name";
 538                 }
 539                 if ( strval( $fragment ) != '' ) {
 540                         $name .= '#' . $fragment;
 541                 }
 542                 return $name;
 543         }
 544
 545         /**
 546          * Escape a text fragment, say from a link, for a URL
 547          *
 548          * @param string $fragment containing a URL or link fragment (after the "#")
 549          * @return String: escaped string
 550          */
 551         static function escapeFragmentForURL( $fragment ) {
 552                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 553                 # fragments appear not to work in IE (at least up to 7) or in at least
 554                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 555                 # to care if they aren't encoded.
 556                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 557         }
 558
 559         /**
 560          * Callback for usort() to do title sorts by (namespace, title)
 561          *
 562          * @param $a Title
 563          * @param $b Title
 564          *
 565          * @return Integer: result of string comparison, or namespace comparison
 566          */
 567         public static function compare( $a, $b ) {
 568                 if ( $a->getNamespace() == $b->getNamespace() ) {
 569                         return strcmp( $a->getText(), $b->getText() );
 570                 } else {
 571                         return $a->getNamespace() - $b->getNamespace();
 572                 }
 573         }
 574
 575         /**
 576          * Determine whether the object refers to a page within
 577          * this project.
 578          *
 579          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 580          */
 581         public function isLocal() {
 582                 if ( $this->mInterwiki != '' ) {
 583                         $iw = Interwiki::fetch( $this->mInterwiki );
 584                         if ( $iw ) {
 585                                 return $iw->isLocal();
 586                         }
 587                 }
 588                 return true;
 589         }
 590
 591         /**
 592          * Is this Title interwiki?
 593          *
 594          * @return Bool
 595          */
 596         public function isExternal() {
 597                 return ( $this->mInterwiki != '' );
 598         }
 599
 600         /**
 601          * Get the interwiki prefix (or null string)
 602          *
 603          * @return String Interwiki prefix
 604          */
 605         public function getInterwiki() {
 606                 return $this->mInterwiki;
 607         }
 608
 609         /**
 610          * Determine whether the object refers to a page within
 611          * this project and is transcludable.
 612          *
 613          * @return Bool TRUE if this is transcludable
 614          */
 615         public function isTrans() {
 616                 if ( $this->mInterwiki == '' ) {
 617                         return false;
 618                 }
 619
 620                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 621         }
 622
 623         /**
 624          * Returns the DB name of the distant wiki which owns the object.
 625          *
 626          * @return String the DB name
 627          */
 628         public function getTransWikiID() {
 629                 if ( $this->mInterwiki == '' ) {
 630                         return false;
 631                 }
 632
 633                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 634         }
 635
 636         /**
 637          * Get the text form (spaces not underscores) of the main part
 638          *
 639          * @return String Main part of the title
 640          */
 641         public function getText() {
 642                 return $this->mTextform;
 643         }
 644
 645         /**
 646          * Get the URL-encoded form of the main part
 647          *
 648          * @return String Main part of the title, URL-encoded
 649          */
 650         public function getPartialURL() {
 651                 return $this->mUrlform;
 652         }
 653
 654         /**
 655          * Get the main part with underscores
 656          *
 657          * @return String: Main part of the title, with underscores
 658          */
 659         public function getDBkey() {
 660                 return $this->mDbkeyform;
 661         }
 662
 663         /**
 664          * Get the DB key with the initial letter case as specified by the user
 665          *
 666          * @return String DB key
 667          */
 668         function getUserCaseDBKey() {
 669                 return $this->mUserCaseDBKey;
 670         }
 671
 672         /**
 673          * Get the namespace index, i.e. one of the NS_xxxx constants.
 674          *
 675          * @return Integer: Namespace index
 676          */
 677         public function getNamespace() {
 678                 return $this->mNamespace;
 679         }
 680
 681         /**
 682          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 683          *
 684          * @throws MWException
 685          * @return String: Content model id
 686          */
 687         public function getContentModel() {
 688                 if ( !$this->mContentModel ) {
 689                         $linkCache = LinkCache::singleton();
 690                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 691                 }
 692
 693                 if ( !$this->mContentModel ) {
 694                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 695                 }
 696
 697                 if ( !$this->mContentModel ) {
 698                         throw new MWException( 'Failed to determine content model!' );
 699                 }
 700
 701                 return $this->mContentModel;
 702         }
 703
 704         /**
 705          * Convenience method for checking a title's content model name
 706          *
 707          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 708          * @return Boolean true if $this->getContentModel() == $id
 709          */
 710         public function hasContentModel( $id ) {
 711                 return $this->getContentModel() == $id;
 712         }
 713
 714         /**
 715          * Get the namespace text
 716          *
 717          * @return String: Namespace text
 718          */
 719         public function getNsText() {
 720                 global $wgContLang;
 721
 722                 if ( $this->mInterwiki != '' ) {
 723                         // This probably shouldn't even happen. ohh man, oh yuck.
 724                         // But for interwiki transclusion it sometimes does.
 725                         // Shit. Shit shit shit.
 726                         //
 727                         // Use the canonical namespaces if possible to try to
 728                         // resolve a foreign namespace.
 729                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 730                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 731                         }
 732                 }
 733
 734                 if ( $wgContLang->needsGenderDistinction() &&
 735                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 736                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 737                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 738                 }
 739
 740                 return $wgContLang->getNsText( $this->mNamespace );
 741         }
 742
 743         /**
 744          * Get the namespace text of the subject (rather than talk) page
 745          *
 746          * @return String Namespace text
 747          */
 748         public function getSubjectNsText() {
 749                 global $wgContLang;
 750                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 751         }
 752
 753         /**
 754          * Get the namespace text of the talk page
 755          *
 756          * @return String Namespace text
 757          */
 758         public function getTalkNsText() {
 759                 global $wgContLang;
 760                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 761         }
 762
 763         /**
 764          * Could this title have a corresponding talk page?
 765          *
 766          * @return Bool TRUE or FALSE
 767          */
 768         public function canTalk() {
 769                 return( MWNamespace::canTalk( $this->mNamespace ) );
 770         }
 771
 772         /**
 773          * Is this in a namespace that allows actual pages?
 774          *
 775          * @return Bool
 776          * @internal note -- uses hardcoded namespace index instead of constants
 777          */
 778         public function canExist() {
 779                 return $this->mNamespace >= NS_MAIN;
 780         }
 781
 782         /**
 783          * Can this title be added to a user's watchlist?
 784          *
 785          * @return Bool TRUE or FALSE
 786          */
 787         public function isWatchable() {
 788                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 789         }
 790
 791         /**
 792          * Returns true if this is a special page.
 793          *
 794          * @return boolean
 795          */
 796         public function isSpecialPage() {
 797                 return $this->getNamespace() == NS_SPECIAL;
 798         }
 799
 800         /**
 801          * Returns true if this title resolves to the named special page
 802          *
 803          * @param string $name The special page name
 804          * @return boolean
 805          */
 806         public function isSpecial( $name ) {
 807                 if ( $this->isSpecialPage() ) {
 808                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 809                         if ( $name == $thisName ) {
 810                                 return true;
 811                         }
 812                 }
 813                 return false;
 814         }
 815
 816         /**
 817          * If the Title refers to a special page alias which is not the local default, resolve
 818          * the alias, and localise the name as necessary.  Otherwise, return $this
 819          *
 820          * @return Title
 821          */
 822         public function fixSpecialName() {
 823                 if ( $this->isSpecialPage() ) {
 824                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 825                         if ( $canonicalName ) {
 826                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 827                                 if ( $localName != $this->mDbkeyform ) {
 828                                         return Title::makeTitle( NS_SPECIAL, $localName );
 829                                 }
 830                         }
 831                 }
 832                 return $this;
 833         }
 834
 835         /**
 836          * Returns true if the title is inside the specified namespace.
 837          *
 838          * Please make use of this instead of comparing to getNamespace()
 839          * This function is much more resistant to changes we may make
 840          * to namespaces than code that makes direct comparisons.
 841          * @param int $ns The namespace
 842          * @return bool
 843          * @since 1.19
 844          */
 845         public function inNamespace( $ns ) {
 846                 return MWNamespace::equals( $this->getNamespace(), $ns );
 847         }
 848
 849         /**
 850          * Returns true if the title is inside one of the specified namespaces.
 851          *
 852          * @param ...$namespaces The namespaces to check for
 853          * @return bool
 854          * @since 1.19
 855          */
 856         public function inNamespaces( /* ... */ ) {
 857                 $namespaces = func_get_args();
 858                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 859                         $namespaces = $namespaces[0];
 860                 }
 861
 862                 foreach ( $namespaces as $ns ) {
 863                         if ( $this->inNamespace( $ns ) ) {
 864                                 return true;
 865                         }
 866                 }
 867
 868                 return false;
 869         }
 870
 871         /**
 872          * Returns true if the title has the same subject namespace as the
 873          * namespace specified.
 874          * For example this method will take NS_USER and return true if namespace
 875          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 876          * as their subject namespace.
 877          *
 878          * This is MUCH simpler than individually testing for equivalence
 879          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 880          * @since 1.19
 881          * @param $ns int
 882          * @return bool
 883          */
 884         public function hasSubjectNamespace( $ns ) {
 885                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 886         }
 887
 888         /**
 889          * Is this Title in a namespace which contains content?
 890          * In other words, is this a content page, for the purposes of calculating
 891          * statistics, etc?
 892          *
 893          * @return Boolean
 894          */
 895         public function isContentPage() {
 896                 return MWNamespace::isContent( $this->getNamespace() );
 897         }
 898
 899         /**
 900          * Would anybody with sufficient privileges be able to move this page?
 901          * Some pages just aren't movable.
 902          *
 903          * @return Bool TRUE or FALSE
 904          */
 905         public function isMovable() {
 906                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 907                         // Interwiki title or immovable namespace. Hooks don't get to override here
 908                         return false;
 909                 }
 910
 911                 $result = true;
 912                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 913                 return $result;
 914         }
 915
 916         /**
 917          * Is this the mainpage?
 918          * @note Title::newFromText seems to be sufficiently optimized by the title
 919          * cache that we don't need to over-optimize by doing direct comparisons and
 920          * accidentally creating new bugs where $title->equals( Title::newFromText() )
 921          * ends up reporting something differently than $title->isMainPage();
 922          *
 923          * @since 1.18
 924          * @return Bool
 925          */
 926         public function isMainPage() {
 927                 return $this->equals( Title::newMainPage() );
 928         }
 929
 930         /**
 931          * Is this a subpage?
 932          *
 933          * @return Bool
 934          */
 935         public function isSubpage() {
 936                 return MWNamespace::hasSubpages( $this->mNamespace )
 937                         ? strpos( $this->getText(), '/' ) !== false
 938                         : false;
 939         }
 940
 941         /**
 942          * Is this a conversion table for the LanguageConverter?
 943          *
 944          * @return Bool
 945          */
 946         public function isConversionTable() {
 947                 //@todo: ConversionTable should become a separate content model.
 948
 949                 return $this->getNamespace() == NS_MEDIAWIKI &&
 950                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 951         }
 952
 953         /**
 954          * Does that page contain wikitext, or it is JS, CSS or whatever?
 955          *
 956          * @return Bool
 957          */
 958         public function isWikitextPage() {
 959                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 960         }
 961
 962         /**
 963          * Could this page contain custom CSS or JavaScript for the global UI.
 964          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 965          * or CONTENT_MODEL_JAVASCRIPT.
 966          *
 967          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 968          *
 969          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 970          *
 971          * @return Bool
 972          */
 973         public function isCssOrJsPage() {
 974                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 975                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 976                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 977
 978                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 979                 #      hook functions can force this method to return true even outside the mediawiki namespace.
 980
 981                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 982
 983                 return $isCssOrJsPage;
 984         }
 985
 986         /**
 987          * Is this a .css or .js subpage of a user page?
 988          * @return Bool
 989          */
 990         public function isCssJsSubpage() {
 991                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 992                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 993                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 994         }
 995
 996         /**
 997          * Trim down a .css or .js subpage title to get the corresponding skin name
 998          *
 999          * @return string containing skin name from .css or .js subpage title
1000          */
1001         public function getSkinFromCssJsSubpage() {
1002                 $subpage = explode( '/', $this->mTextform );
1003                 $subpage = $subpage[count( $subpage ) - 1];
1004                 $lastdot = strrpos( $subpage, '.' );
1005                 if ( $lastdot === false ) {
1006                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1007                 }
1008                 return substr( $subpage, 0, $lastdot );
1009         }
1010
1011         /**
1012          * Is this a .css subpage of a user page?
1013          *
1014          * @return Bool
1015          */
1016         public function isCssSubpage() {
1017                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1018                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1019         }
1020
1021         /**
1022          * Is this a .js subpage of a user page?
1023          *
1024          * @return Bool
1025          */
1026         public function isJsSubpage() {
1027                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1028                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1029         }
1030
1031         /**
1032          * Is this a talk page of some sort?
1033          *
1034          * @return Bool
1035          */
1036         public function isTalkPage() {
1037                 return MWNamespace::isTalk( $this->getNamespace() );
1038         }
1039
1040         /**
1041          * Get a Title object associated with the talk page of this article
1042          *
1043          * @return Title the object for the talk page
1044          */
1045         public function getTalkPage() {
1046                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1047         }
1048
1049         /**
1050          * Get a title object associated with the subject page of this
1051          * talk page
1052          *
1053          * @return Title the object for the subject page
1054          */
1055         public function getSubjectPage() {
1056                 // Is this the same title?
1057                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1058                 if ( $this->getNamespace() == $subjectNS ) {
1059                         return $this;
1060                 }
1061                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1062         }
1063
1064         /**
1065          * Get the default namespace index, for when there is no namespace
1066          *
1067          * @return Int Default namespace index
1068          */
1069         public function getDefaultNamespace() {
1070                 return $this->mDefaultNamespace;
1071         }
1072
1073         /**
1074          * Get title for search index
1075          *
1076          * @return String a stripped-down title string ready for the
1077          *  search index
1078          */
1079         public function getIndexTitle() {
1080                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1081         }
1082
1083         /**
1084          * Get the Title fragment (i.e.\ the bit after the #) in text form
1085          *
1086          * @return String Title fragment
1087          */
1088         public function getFragment() {
1089                 return $this->mFragment;
1090         }
1091
1092         /**
1093          * Get the fragment in URL form, including the "#" character if there is one
1094          * @return String Fragment in URL form
1095          */
1096         public function getFragmentForURL() {
1097                 if ( $this->mFragment == '' ) {
1098                         return '';
1099                 } else {
1100                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1101                 }
1102         }
1103
1104         /**
1105          * Set the fragment for this title. Removes the first character from the
1106          * specified fragment before setting, so it assumes you're passing it with
1107          * an initial "#".
1108          *
1109          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1110          * Still in active use privately.
1111          *
1112          * @param string $fragment text
1113          */
1114         public function setFragment( $fragment ) {
1115                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1116         }
1117
1118         /**
1119          * Prefix some arbitrary text with the namespace or interwiki prefix
1120          * of this object
1121          *
1122          * @param string $name the text
1123          * @return String the prefixed text
1124          * @private
1125          */
1126         private function prefix( $name ) {
1127                 $p = '';
1128                 if ( $this->mInterwiki != '' ) {
1129                         $p = $this->mInterwiki . ':';
1130                 }
1131
1132                 if ( 0 != $this->mNamespace ) {
1133                         $p .= $this->getNsText() . ':';
1134                 }
1135                 return $p . $name;
1136         }
1137
1138         /**
1139          * Get the prefixed database key form
1140          *
1141          * @return String the prefixed title, with underscores and
1142          *  any interwiki and namespace prefixes
1143          */
1144         public function getPrefixedDBkey() {
1145                 $s = $this->prefix( $this->mDbkeyform );
1146                 $s = str_replace( ' ', '_', $s );
1147                 return $s;
1148         }
1149
1150         /**
1151          * Get the prefixed title with spaces.
1152          * This is the form usually used for display
1153          *
1154          * @return String the prefixed title, with spaces
1155          */
1156         public function getPrefixedText() {
1157                 // @todo FIXME: Bad usage of empty() ?
1158                 if ( empty( $this->mPrefixedText ) ) {
1159                         $s = $this->prefix( $this->mTextform );
1160                         $s = str_replace( '_', ' ', $s );
1161                         $this->mPrefixedText = $s;
1162                 }
1163                 return $this->mPrefixedText;
1164         }
1165
1166         /**
1167          * Return a string representation of this title
1168          *
1169          * @return String representation of this title
1170          */
1171         public function __toString() {
1172                 return $this->getPrefixedText();
1173         }
1174
1175         /**
1176          * Get the prefixed title with spaces, plus any fragment
1177          * (part beginning with '#')
1178          *
1179          * @return String the prefixed title, with spaces and the fragment, including '#'
1180          */
1181         public function getFullText() {
1182                 $text = $this->getPrefixedText();
1183                 if ( $this->mFragment != '' ) {
1184                         $text .= '#' . $this->mFragment;
1185                 }
1186                 return $text;
1187         }
1188
1189         /**
1190          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1191          *
1192          * @par Example:
1193          * @code
1194          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1195          * # returns: 'Foo'
1196          * @endcode
1197          *
1198          * @return String Root name
1199          * @since 1.20
1200          */
1201         public function getRootText() {
1202                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1203                         return $this->getText();
1204                 }
1205
1206                 return strtok( $this->getText(), '/' );
1207         }
1208
1209         /**
1210          * Get the root page name title, i.e. the leftmost part before any slashes
1211          *
1212          * @par Example:
1213          * @code
1214          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1215          * # returns: Title{User:Foo}
1216          * @endcode
1217          *
1218          * @return Title Root title
1219          * @since 1.20
1220          */
1221         public function getRootTitle() {
1222                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1223         }
1224
1225         /**
1226          * Get the base page name without a namespace, i.e. the part before the subpage name
1227          *
1228          * @par Example:
1229          * @code
1230          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1231          * # returns: 'Foo/Bar'
1232          * @endcode
1233          *
1234          * @return String Base name
1235          */
1236         public function getBaseText() {
1237                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1238                         return $this->getText();
1239                 }
1240
1241                 $parts = explode( '/', $this->getText() );
1242                 # Don't discard the real title if there's no subpage involved
1243                 if ( count( $parts ) > 1 ) {
1244                         unset( $parts[count( $parts ) - 1] );
1245                 }
1246                 return implode( '/', $parts );
1247         }
1248
1249         /**
1250          * Get the base page name title, i.e. the part before the subpage name
1251          *
1252          * @par Example:
1253          * @code
1254          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1255          * # returns: Title{User:Foo/Bar}
1256          * @endcode
1257          *
1258          * @return Title Base title
1259          * @since 1.20
1260          */
1261         public function getBaseTitle() {
1262                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1263         }
1264
1265         /**
1266          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1267          *
1268          * @par Example:
1269          * @code
1270          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1271          * # returns: "Baz"
1272          * @endcode
1273          *
1274          * @return String Subpage name
1275          */
1276         public function getSubpageText() {
1277                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1278                         return( $this->mTextform );
1279                 }
1280                 $parts = explode( '/', $this->mTextform );
1281                 return( $parts[count( $parts ) - 1] );
1282         }
1283
1284         /**
1285          * Get the title for a subpage of the current page
1286          *
1287          * @par Example:
1288          * @code
1289          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1290          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1291          * @endcode
1292          *
1293          * @param string $text The subpage name to add to the title
1294          * @return Title Subpage title
1295          * @since 1.20
1296          */
1297         public function getSubpage( $text ) {
1298                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1299         }
1300
1301         /**
1302          * Get the HTML-escaped displayable text form.
1303          * Used for the title field in <a> tags.
1304          *
1305          * @return String the text, including any prefixes
1306          * @deprecated since 1.19
1307          */
1308         public function getEscapedText() {
1309                 wfDeprecated( __METHOD__, '1.19' );
1310                 return htmlspecialchars( $this->getPrefixedText() );
1311         }
1312
1313         /**
1314          * Get a URL-encoded form of the subpage text
1315          *
1316          * @return String URL-encoded subpage name
1317          */
1318         public function getSubpageUrlForm() {
1319                 $text = $this->getSubpageText();
1320                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1321                 return( $text );
1322         }
1323
1324         /**
1325          * Get a URL-encoded title (not an actual URL) including interwiki
1326          *
1327          * @return String the URL-encoded form
1328          */
1329         public function getPrefixedURL() {
1330                 $s = $this->prefix( $this->mDbkeyform );
1331                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1332                 return $s;
1333         }
1334
1335         /**
1336          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1337          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1338          * second argument named variant. This was deprecated in favor
1339          * of passing an array of option with a "variant" key
1340          * Once $query2 is removed for good, this helper can be dropped
1341          * and the wfArrayToCgi moved to getLocalURL();
1342          *
1343          * @since 1.19 (r105919)
1344          * @param $query
1345          * @param $query2 bool
1346          * @return String
1347          */
1348         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1349                 if ( $query2 !== false ) {
1350                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1351                                 "method called with a second parameter is deprecated. Add your " .
1352                                 "parameter to an array passed as the first parameter.", "1.19" );
1353                 }
1354                 if ( is_array( $query ) ) {
1355                         $query = wfArrayToCgi( $query );
1356                 }
1357                 if ( $query2 ) {
1358                         if ( is_string( $query2 ) ) {
1359                                 // $query2 is a string, we will consider this to be
1360                                 // a deprecated $variant argument and add it to the query
1361                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1362                         } else {
1363                                 $query2 = wfArrayToCgi( $query2 );
1364                         }
1365                         // If we have $query content add a & to it first
1366                         if ( $query ) {
1367                                 $query .= '&';
1368                         }
1369                         // Now append the queries together
1370                         $query .= $query2;
1371                 }
1372                 return $query;
1373         }
1374
1375         /**
1376          * Get a real URL referring to this title, with interwiki link and
1377          * fragment
1378          *
1379          * See getLocalURL for the arguments.
1380          *
1381          * @see self::getLocalURL
1382          * @see wfExpandUrl
1383          * @param $query
1384          * @param $query2 bool
1385          * @param $proto Protocol type to use in URL
1386          * @return String the URL
1387          */
1388         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1389                 $query = self::fixUrlQueryArgs( $query, $query2 );
1390
1391                 # Hand off all the decisions on urls to getLocalURL
1392                 $url = $this->getLocalURL( $query );
1393
1394                 # Expand the url to make it a full url. Note that getLocalURL has the
1395                 # potential to output full urls for a variety of reasons, so we use
1396                 # wfExpandUrl instead of simply prepending $wgServer
1397                 $url = wfExpandUrl( $url, $proto );
1398
1399                 # Finally, add the fragment.
1400                 $url .= $this->getFragmentForURL();
1401
1402                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1403                 return $url;
1404         }
1405
1406         /**
1407          * Get a URL with no fragment or server name.  If this page is generated
1408          * with action=render, $wgServer is prepended.
1409          *
1410          * @param string|array $query an optional query string,
1411          *   not used for interwiki links. Can be specified as an associative array as well,
1412          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1413          *   Some query patterns will trigger various shorturl path replacements.
1414          * @param $query2 Mixed: An optional secondary query array. This one MUST
1415          *   be an array. If a string is passed it will be interpreted as a deprecated
1416          *   variant argument and urlencoded into a variant= argument.
1417          *   This second query argument will be added to the $query
1418          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1419          *   pair in the first parameter array instead.
1420          *
1421          * @return String the URL
1422          */
1423         public function getLocalURL( $query = '', $query2 = false ) {
1424                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1425
1426                 $query = self::fixUrlQueryArgs( $query, $query2 );
1427
1428                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1429                 if ( $interwiki ) {
1430                         $namespace = $this->getNsText();
1431                         if ( $namespace != '' ) {
1432                                 # Can this actually happen? Interwikis shouldn't be parsed.
1433                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1434                                 $namespace .= ':';
1435                         }
1436                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1437                         $url = wfAppendQuery( $url, $query );
1438                 } else {
1439                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1440                         if ( $query == '' ) {
1441                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1442                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1443                         } else {
1444                                 global $wgVariantArticlePath, $wgActionPaths;
1445                                 $url = false;
1446                                 $matches = array();
1447
1448                                 if ( !empty( $wgActionPaths ) &&
1449                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1450                                 {
1451                                         $action = urldecode( $matches[2] );
1452                                         if ( isset( $wgActionPaths[$action] ) ) {
1453                                                 $query = $matches[1];
1454                                                 if ( isset( $matches[4] ) ) {
1455                                                         $query .= $matches[4];
1456                                                 }
1457                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1458                                                 if ( $query != '' ) {
1459                                                         $url = wfAppendQuery( $url, $query );
1460                                                 }
1461                                         }
1462                                 }
1463
1464                                 if ( $url === false &&
1465                                         $wgVariantArticlePath &&
1466                                         $this->getPageLanguage()->hasVariants() &&
1467                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1468                                 {
1469                                         $variant = urldecode( $matches[1] );
1470                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1471                                                 // Only do the variant replacement if the given variant is a valid
1472                                                 // variant for the page's language.
1473                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1474                                                 $url = str_replace( '$1', $dbkey, $url );
1475                                         }
1476                                 }
1477
1478                                 if ( $url === false ) {
1479                                         if ( $query == '-' ) {
1480                                                 $query = '';
1481                                         }
1482                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1483                                 }
1484                         }
1485
1486                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1487
1488                         // @todo FIXME: This causes breakage in various places when we
1489                         // actually expected a local URL and end up with dupe prefixes.
1490                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1491                                 $url = $wgServer . $url;
1492                         }
1493                 }
1494                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1495                 return $url;
1496         }
1497
1498         /**
1499          * Get a URL that's the simplest URL that will be valid to link, locally,
1500          * to the current Title.  It includes the fragment, but does not include
1501          * the server unless action=render is used (or the link is external).  If
1502          * there's a fragment but the prefixed text is empty, we just return a link
1503          * to the fragment.
1504          *
1505          * The result obviously should not be URL-escaped, but does need to be
1506          * HTML-escaped if it's being output in HTML.
1507          *
1508          * See getLocalURL for the arguments.
1509          *
1510          * @param $query
1511          * @param $query2 bool
1512          * @param $proto Protocol to use; setting this will cause a full URL to be used
1513          * @see self::getLocalURL
1514          * @return String the URL
1515          */
1516         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1517                 wfProfileIn( __METHOD__ );
1518                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1519                         $ret = $this->getFullURL( $query, $query2, $proto );
1520                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1521                         $ret = $this->getFragmentForURL();
1522                 } else {
1523                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1524                 }
1525                 wfProfileOut( __METHOD__ );
1526                 return $ret;
1527         }
1528
1529         /**
1530          * Get an HTML-escaped version of the URL form, suitable for
1531          * using in a link, without a server name or fragment
1532          *
1533          * See getLocalURL for the arguments.
1534          *
1535          * @see self::getLocalURL
1536          * @param $query string
1537          * @param $query2 bool|string
1538          * @return String the URL
1539          * @deprecated since 1.19
1540          */
1541         public function escapeLocalURL( $query = '', $query2 = false ) {
1542                 wfDeprecated( __METHOD__, '1.19' );
1543                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1544         }
1545
1546         /**
1547          * Get an HTML-escaped version of the URL form, suitable for
1548          * using in a link, including the server name and fragment
1549          *
1550          * See getLocalURL for the arguments.
1551          *
1552          * @see self::getLocalURL
1553          * @return String the URL
1554          * @deprecated since 1.19
1555          */
1556         public function escapeFullURL( $query = '', $query2 = false ) {
1557                 wfDeprecated( __METHOD__, '1.19' );
1558                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1559         }
1560
1561         /**
1562          * Get the URL form for an internal link.
1563          * - Used in various Squid-related code, in case we have a different
1564          * internal hostname for the server from the exposed one.
1565          *
1566          * This uses $wgInternalServer to qualify the path, or $wgServer
1567          * if $wgInternalServer is not set. If the server variable used is
1568          * protocol-relative, the URL will be expanded to http://
1569          *
1570          * See getLocalURL for the arguments.
1571          *
1572          * @see self::getLocalURL
1573          * @return String the URL
1574          */
1575         public function getInternalURL( $query = '', $query2 = false ) {
1576                 global $wgInternalServer, $wgServer;
1577                 $query = self::fixUrlQueryArgs( $query, $query2 );
1578                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1579                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1580                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1581                 return $url;
1582         }
1583
1584         /**
1585          * Get the URL for a canonical link, for use in things like IRC and
1586          * e-mail notifications. Uses $wgCanonicalServer and the
1587          * GetCanonicalURL hook.
1588          *
1589          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1590          *
1591          * See getLocalURL for the arguments.
1592          *
1593          * @see self::getLocalURL
1594          * @return string The URL
1595          * @since 1.18
1596          */
1597         public function getCanonicalURL( $query = '', $query2 = false ) {
1598                 $query = self::fixUrlQueryArgs( $query, $query2 );
1599                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1600                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1601                 return $url;
1602         }
1603
1604         /**
1605          * HTML-escaped version of getCanonicalURL()
1606          *
1607          * See getLocalURL for the arguments.
1608          *
1609          * @see self::getLocalURL
1610          * @since 1.18
1611          * @return string
1612          * @deprecated since 1.19
1613          */
1614         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1615                 wfDeprecated( __METHOD__, '1.19' );
1616                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1617         }
1618
1619         /**
1620          * Get the edit URL for this Title
1621          *
1622          * @return String the URL, or a null string if this is an
1623          *  interwiki link
1624          */
1625         public function getEditURL() {
1626                 if ( $this->mInterwiki != '' ) {
1627                         return '';
1628                 }
1629                 $s = $this->getLocalURL( 'action=edit' );
1630
1631                 return $s;
1632         }
1633
1634         /**
1635          * Is $wgUser watching this page?
1636          *
1637          * @deprecated in 1.20; use User::isWatched() instead.
1638          * @return Bool
1639          */
1640         public function userIsWatching() {
1641                 global $wgUser;
1642
1643                 if ( is_null( $this->mWatched ) ) {
1644                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1645                                 $this->mWatched = false;
1646                         } else {
1647                                 $this->mWatched = $wgUser->isWatched( $this );
1648                         }
1649                 }
1650                 return $this->mWatched;
1651         }
1652
1653         /**
1654          * Can $wgUser read this page?
1655          *
1656          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1657          * @return Bool
1658          * @todo fold these checks into userCan()
1659          */
1660         public function userCanRead() {
1661                 wfDeprecated( __METHOD__, '1.19' );
1662                 return $this->userCan( 'read' );
1663         }
1664
1665         /**
1666          * Can $user perform $action on this page?
1667          * This skips potentially expensive cascading permission checks
1668          * as well as avoids expensive error formatting
1669          *
1670          * Suitable for use for nonessential UI controls in common cases, but
1671          * _not_ for functional access control.
1672          *
1673          * May provide false positives, but should never provide a false negative.
1674          *
1675          * @param string $action action that permission needs to be checked for
1676          * @param $user User to check (since 1.19); $wgUser will be used if not
1677          *              provided.
1678          * @return Bool
1679          */
1680         public function quickUserCan( $action, $user = null ) {
1681                 return $this->userCan( $action, $user, false );
1682         }
1683
1684         /**
1685          * Can $user perform $action on this page?
1686          *
1687          * @param string $action action that permission needs to be checked for
1688          * @param $user User to check (since 1.19); $wgUser will be used if not
1689          *   provided.
1690          * @param bool $doExpensiveQueries Set this to false to avoid doing
1691          *   unnecessary queries.
1692          * @return Bool
1693          */
1694         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1695                 if ( !$user instanceof User ) {
1696                         global $wgUser;
1697                         $user = $wgUser;
1698                 }
1699                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1700         }
1701
1702         /**
1703          * Can $user perform $action on this page?
1704          *
1705          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1706          *
1707          * @param string $action action that permission needs to be checked for
1708          * @param $user User to check
1709          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1710          *   queries by skipping checks for cascading protections and user blocks.
1711          * @param array $ignoreErrors of Strings Set this to a list of message keys
1712          *   whose corresponding errors may be ignored.
1713          * @return Array of arguments to wfMessage to explain permissions problems.
1714          */
1715         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1716                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1717
1718                 // Remove the errors being ignored.
1719                 foreach ( $errors as $index => $error ) {
1720                         $error_key = is_array( $error ) ? $error[0] : $error;
1721
1722                         if ( in_array( $error_key, $ignoreErrors ) ) {
1723                                 unset( $errors[$index] );
1724                         }
1725                 }
1726
1727                 return $errors;
1728         }
1729
1730         /**
1731          * Permissions checks that fail most often, and which are easiest to test.
1732          *
1733          * @param string $action the action to check
1734          * @param $user User user to check
1735          * @param array $errors list of current errors
1736          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1737          * @param $short Boolean short circuit on first error
1738          *
1739          * @return Array list of errors
1740          */
1741         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1742                 if ( $action == 'create' ) {
1743                         if (
1744                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1745                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1746                         ) {
1747                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1748                         }
1749                 } elseif ( $action == 'move' ) {
1750                         if ( !$user->isAllowed( 'move-rootuserpages' )
1751                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1752                                 // Show user page-specific message only if the user can move other pages
1753                                 $errors[] = array( 'cant-move-user-page' );
1754                         }
1755
1756                         // Check if user is allowed to move files if it's a file
1757                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1758                                 $errors[] = array( 'movenotallowedfile' );
1759                         }
1760
1761                         if ( !$user->isAllowed( 'move' ) ) {
1762                                 // User can't move anything
1763                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1764                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1765                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1766                                         // custom message if logged-in users without any special rights can move
1767                                         $errors[] = array( 'movenologintext' );
1768                                 } else {
1769                                         $errors[] = array( 'movenotallowed' );
1770                                 }
1771                         }
1772                 } elseif ( $action == 'move-target' ) {
1773                         if ( !$user->isAllowed( 'move' ) ) {
1774                                 // User can't move anything
1775                                 $errors[] = array( 'movenotallowed' );
1776                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1777                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1778                                 // Show user page-specific message only if the user can move other pages
1779                                 $errors[] = array( 'cant-move-to-user-page' );
1780                         }
1781                 } elseif ( !$user->isAllowed( $action ) ) {
1782                         $errors[] = $this->missingPermissionError( $action, $short );
1783                 }
1784
1785                 return $errors;
1786         }
1787
1788         /**
1789          * Add the resulting error code to the errors array
1790          *
1791          * @param array $errors list of current errors
1792          * @param $result Mixed result of errors
1793          *
1794          * @return Array list of errors
1795          */
1796         private function resultToError( $errors, $result ) {
1797                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1798                         // A single array representing an error
1799                         $errors[] = $result;
1800                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1801                         // A nested array representing multiple errors
1802                         $errors = array_merge( $errors, $result );
1803                 } elseif ( $result !== '' && is_string( $result ) ) {
1804                         // A string representing a message-id
1805                         $errors[] = array( $result );
1806                 } elseif ( $result === false ) {
1807                         // a generic "We don't want them to do that"
1808                         $errors[] = array( 'badaccess-group0' );
1809                 }
1810                 return $errors;
1811         }
1812
1813         /**
1814          * Check various permission hooks
1815          *
1816          * @param string $action the action to check
1817          * @param $user User user to check
1818          * @param array $errors list of current errors
1819          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1820          * @param $short Boolean short circuit on first error
1821          *
1822          * @return Array list of errors
1823          */
1824         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1825                 // Use getUserPermissionsErrors instead
1826                 $result = '';
1827                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1828                         return $result ? array() : array( array( 'badaccess-group0' ) );
1829                 }
1830                 // Check getUserPermissionsErrors hook
1831                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1832                         $errors = $this->resultToError( $errors, $result );
1833                 }
1834                 // Check getUserPermissionsErrorsExpensive hook
1835                 if (
1836                         $doExpensiveQueries
1837                         && !( $short && count( $errors ) > 0 )
1838                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
1839                 ) {
1840                         $errors = $this->resultToError( $errors, $result );
1841                 }
1842
1843                 return $errors;
1844         }
1845
1846         /**
1847          * Check permissions on special pages & namespaces
1848          *
1849          * @param string $action the action to check
1850          * @param $user User user to check
1851          * @param array $errors list of current errors
1852          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1853          * @param $short Boolean short circuit on first error
1854          *
1855          * @return Array list of errors
1856          */
1857         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1858                 # Only 'createaccount' can be performed on special pages,
1859                 # which don't actually exist in the DB.
1860                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
1861                         $errors[] = array( 'ns-specialprotected' );
1862                 }
1863
1864                 # Check $wgNamespaceProtection for restricted namespaces
1865                 if ( $this->isNamespaceProtected( $user ) ) {
1866                         $ns = $this->mNamespace == NS_MAIN ?
1867                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1868                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1869                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
1870                 }
1871
1872                 return $errors;
1873         }
1874
1875         /**
1876          * Check CSS/JS sub-page permissions
1877          *
1878          * @param string $action the action to check
1879          * @param $user User user to check
1880          * @param array $errors list of current errors
1881          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1882          * @param $short Boolean short circuit on first error
1883          *
1884          * @return Array list of errors
1885          */
1886         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1887                 # Protect css/js subpages of user pages
1888                 # XXX: this might be better using restrictions
1889                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1890                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1891                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1892                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1893                                 $errors[] = array( 'customcssprotected' );
1894                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1895                                 $errors[] = array( 'customjsprotected' );
1896                         }
1897                 }
1898
1899                 return $errors;
1900         }
1901
1902         /**
1903          * Check against page_restrictions table requirements on this
1904          * page. The user must possess all required rights for this
1905          * action.
1906          *
1907          * @param string $action the action to check
1908          * @param $user User user to check
1909          * @param array $errors list of current errors
1910          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1911          * @param $short Boolean short circuit on first error
1912          *
1913          * @return Array list of errors
1914          */
1915         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1916                 foreach ( $this->getRestrictions( $action ) as $right ) {
1917                         // Backwards compatibility, rewrite sysop -> protect
1918                         if ( $right == 'sysop' ) {
1919                                 $right = 'protect';
1920                         }
1921                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1922                                 // Users with 'editprotected' permission can edit protected pages
1923                                 // without cascading option turned on.
1924                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1925                                         || $this->mCascadeRestriction )
1926                                 {
1927                                         $errors[] = array( 'protectedpagetext', $right );
1928                                 }
1929                         }
1930                 }
1931
1932                 return $errors;
1933         }
1934
1935         /**
1936          * Check restrictions on cascading pages.
1937          *
1938          * @param string $action the action to check
1939          * @param $user User to check
1940          * @param array $errors list of current errors
1941          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1942          * @param $short Boolean short circuit on first error
1943          *
1944          * @return Array list of errors
1945          */
1946         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1947                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1948                         # We /could/ use the protection level on the source page, but it's
1949                         # fairly ugly as we have to establish a precedence hierarchy for pages
1950                         # included by multiple cascade-protected pages. So just restrict
1951                         # it to people with 'protect' permission, as they could remove the
1952                         # protection anyway.
1953                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1954                         # Cascading protection depends on more than this page...
1955                         # Several cascading protected pages may include this page...
1956                         # Check each cascading level
1957                         # This is only for protection restrictions, not for all actions
1958                         if ( isset( $restrictions[$action] ) ) {
1959                                 foreach ( $restrictions[$action] as $right ) {
1960                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1961                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1962                                                 $pages = '';
1963                                                 foreach ( $cascadingSources as $page ) {
1964                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1965                                                 }
1966                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1967                                         }
1968                                 }
1969                         }
1970                 }
1971
1972                 return $errors;
1973         }
1974
1975         /**
1976          * Check action permissions not already checked in checkQuickPermissions
1977          *
1978          * @param string $action the action to check
1979          * @param $user User to check
1980          * @param array $errors list of current errors
1981          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1982          * @param $short Boolean short circuit on first error
1983          *
1984          * @return Array list of errors
1985          */
1986         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1987                 global $wgDeleteRevisionsLimit, $wgLang;
1988
1989                 if ( $action == 'protect' ) {
1990                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1991                                 // If they can't edit, they shouldn't protect.
1992                                 $errors[] = array( 'protect-cantedit' );
1993                         }
1994                 } elseif ( $action == 'create' ) {
1995                         $title_protection = $this->getTitleProtection();
1996                         if ( $title_protection ) {
1997                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
1998                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1999                                 }
2000                                 if ( $title_protection['pt_create_perm'] == '' ||
2001                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
2002                                 {
2003                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2004                                 }
2005                         }
2006                 } elseif ( $action == 'move' ) {
2007                         // Check for immobile pages
2008                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2009                                 // Specific message for this case
2010                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2011                         } elseif ( !$this->isMovable() ) {
2012                                 // Less specific message for rarer cases
2013                                 $errors[] = array( 'immobile-source-page' );
2014                         }
2015                 } elseif ( $action == 'move-target' ) {
2016                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2017                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2018                         } elseif ( !$this->isMovable() ) {
2019                                 $errors[] = array( 'immobile-target-page' );
2020                         }
2021                 } elseif ( $action == 'delete' ) {
2022                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2023                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
2024                         {
2025                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2026                         }
2027                 }
2028                 return $errors;
2029         }
2030
2031         /**
2032          * Check that the user isn't blocked from editing.
2033          *
2034          * @param string $action the action to check
2035          * @param $user User to check
2036          * @param array $errors list of current errors
2037          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2038          * @param $short Boolean short circuit on first error
2039          *
2040          * @return Array list of errors
2041          */
2042         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2043                 // Account creation blocks handled at userlogin.
2044                 // Unblocking handled in SpecialUnblock
2045                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2046                         return $errors;
2047                 }
2048
2049                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
2050
2051                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2052                         $errors[] = array( 'confirmedittext' );
2053                 }
2054
2055                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2056                         // Don't block the user from editing their own talk page unless they've been
2057                         // explicitly blocked from that too.
2058                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2059                         $block = $user->getBlock();
2060
2061                         // This is from OutputPage::blockedPage
2062                         // Copied at r23888 by werdna
2063
2064                         $id = $user->blockedBy();
2065                         $reason = $user->blockedFor();
2066                         if ( $reason == '' ) {
2067                                 $reason = wfMessage( 'blockednoreason' )->text();
2068                         }
2069                         $ip = $user->getRequest()->getIP();
2070
2071                         if ( is_numeric( $id ) ) {
2072                                 $name = User::whoIs( $id );
2073                         } else {
2074                                 $name = $id;
2075                         }
2076
2077                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2078                         $blockid = $block->getId();
2079                         $blockExpiry = $block->getExpiry();
2080                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2081                         if ( $blockExpiry == 'infinity' ) {
2082                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2083                         } else {
2084                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2085                         }
2086
2087                         $intended = strval( $block->getTarget() );
2088
2089                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2090                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2091                 }
2092
2093                 return $errors;
2094         }
2095
2096         /**
2097          * Check that the user is allowed to read this page.
2098          *
2099          * @param string $action the action to check
2100          * @param $user User to check
2101          * @param array $errors list of current errors
2102          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2103          * @param $short Boolean short circuit on first error
2104          *
2105          * @return Array list of errors
2106          */
2107         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2108                 global $wgWhitelistRead, $wgWhitelistReadRegexp, $wgRevokePermissions;
2109                 static $useShortcut = null;
2110
2111                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2112                 if ( is_null( $useShortcut ) ) {
2113                         $useShortcut = true;
2114                         if ( !User::groupHasPermission( '*', 'read' ) ) {
2115                                 # Not a public wiki, so no shortcut
2116                                 $useShortcut = false;
2117                         } elseif ( !empty( $wgRevokePermissions ) ) {
2118                                 /**
2119                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2120                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2121                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2122                                  * reading is allowed.
2123                                  */
2124                                 foreach ( $wgRevokePermissions as $perms ) {
2125                                         if ( !empty( $perms['read'] ) ) {
2126                                                 # We might be removing the read right from the user, so no shortcut
2127                                                 $useShortcut = false;
2128                                                 break;
2129                                         }
2130                                 }
2131                         }
2132                 }
2133
2134                 $whitelisted = false;
2135                 if ( $useShortcut ) {
2136                         # Shortcut for public wikis, allows skipping quite a bit of code
2137                         $whitelisted = true;
2138                 } elseif ( $user->isAllowed( 'read' ) ) {
2139                         # If the user is allowed to read pages, he is allowed to read all pages
2140                         $whitelisted = true;
2141                 } elseif ( $this->isSpecial( 'Userlogin' )
2142                         || $this->isSpecial( 'ChangePassword' )
2143                         || $this->isSpecial( 'PasswordReset' )
2144                 ) {
2145                         # Always grant access to the login page.
2146                         # Even anons need to be able to log in.
2147                         $whitelisted = true;
2148                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2149                         # Time to check the whitelist
2150                         # Only do these checks is there's something to check against
2151                         $name = $this->getPrefixedText();
2152                         $dbName = $this->getPrefixedDBkey();
2153
2154                         // Check for explicit whitelisting with and without underscores
2155                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2156                                 $whitelisted = true;
2157                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2158                                 # Old settings might have the title prefixed with
2159                                 # a colon for main-namespace pages
2160                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2161                                         $whitelisted = true;
2162                                 }
2163                         } elseif ( $this->isSpecialPage() ) {
2164                                 # If it's a special page, ditch the subpage bit and check again
2165                                 $name = $this->getDBkey();
2166                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2167                                 if ( $name ) {
2168                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2169                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2170                                                 $whitelisted = true;
2171                                         }
2172                                 }
2173                         }
2174                 }
2175
2176                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2177                         $name = $this->getPrefixedText();
2178                         // Check for regex whitelisting
2179                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2180                                 if ( preg_match( $listItem, $name ) ) {
2181                                         $whitelisted = true;
2182                                         break;
2183                                 }
2184                         }
2185                 }
2186
2187                 if ( !$whitelisted ) {
2188                         # If the title is not whitelisted, give extensions a chance to do so...
2189                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2190                         if ( !$whitelisted ) {
2191                                 $errors[] = $this->missingPermissionError( $action, $short );
2192                         }
2193                 }
2194
2195                 return $errors;
2196         }
2197
2198         /**
2199          * Get a description array when the user doesn't have the right to perform
2200          * $action (i.e. when User::isAllowed() returns false)
2201          *
2202          * @param string $action the action to check
2203          * @param $short Boolean short circuit on first error
2204          * @return Array list of errors
2205          */
2206         private function missingPermissionError( $action, $short ) {
2207                 // We avoid expensive display logic for quickUserCan's and such
2208                 if ( $short ) {
2209                         return array( 'badaccess-group0' );
2210                 }
2211
2212                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2213                         User::getGroupsWithPermission( $action ) );
2214
2215                 if ( count( $groups ) ) {
2216                         global $wgLang;
2217                         return array(
2218                                 'badaccess-groups',
2219                                 $wgLang->commaList( $groups ),
2220                                 count( $groups )
2221                         );
2222                 } else {
2223                         return array( 'badaccess-group0' );
2224                 }
2225         }
2226
2227         /**
2228          * Can $user perform $action on this page? This is an internal function,
2229          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2230          * checks on wfReadOnly() and blocks)
2231          *
2232          * @param string $action action that permission needs to be checked for
2233          * @param $user User to check
2234          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2235          * @param bool $short Set this to true to stop after the first permission error.
2236          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2237          */
2238         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2239                 wfProfileIn( __METHOD__ );
2240
2241                 # Read has special handling
2242                 if ( $action == 'read' ) {
2243                         $checks = array(
2244                                 'checkPermissionHooks',
2245                                 'checkReadPermissions',
2246                         );
2247                 } else {
2248                         $checks = array(
2249                                 'checkQuickPermissions',
2250                                 'checkPermissionHooks',
2251                                 'checkSpecialsAndNSPermissions',
2252                                 'checkCSSandJSPermissions',
2253                                 'checkPageRestrictions',
2254                                 'checkCascadingSourcesRestrictions',
2255                                 'checkActionPermissions',
2256                                 'checkUserBlock'
2257                         );
2258                 }
2259
2260                 $errors = array();
2261                 while ( count( $checks ) > 0 &&
2262                                 !( $short && count( $errors ) > 0 ) ) {
2263                         $method = array_shift( $checks );
2264                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2265                 }
2266
2267                 wfProfileOut( __METHOD__ );
2268                 return $errors;
2269         }
2270
2271         /**
2272          * Protect css subpages of user pages: can $wgUser edit
2273          * this page?
2274          *
2275          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2276          * @return Bool
2277          */
2278         public function userCanEditCssSubpage() {
2279                 global $wgUser;
2280                 wfDeprecated( __METHOD__, '1.19' );
2281                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2282                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2283         }
2284
2285         /**
2286          * Protect js subpages of user pages: can $wgUser edit
2287          * this page?
2288          *
2289          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2290          * @return Bool
2291          */
2292         public function userCanEditJsSubpage() {
2293                 global $wgUser;
2294                 wfDeprecated( __METHOD__, '1.19' );
2295                 return (
2296                         ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2297                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform )
2298                 );
2299         }
2300
2301         /**
2302          * Get a filtered list of all restriction types supported by this wiki.
2303          * @param bool $exists True to get all restriction types that apply to
2304          * titles that do exist, False for all restriction types that apply to
2305          * titles that do not exist
2306          * @return array
2307          */
2308         public static function getFilteredRestrictionTypes( $exists = true ) {
2309                 global $wgRestrictionTypes;
2310                 $types = $wgRestrictionTypes;
2311                 if ( $exists ) {
2312                         # Remove the create restriction for existing titles
2313                         $types = array_diff( $types, array( 'create' ) );
2314                 } else {
2315                         # Only the create and upload restrictions apply to non-existing titles
2316                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2317                 }
2318                 return $types;
2319         }
2320
2321         /**
2322          * Returns restriction types for the current Title
2323          *
2324          * @return array applicable restriction types
2325          */
2326         public function getRestrictionTypes() {
2327                 if ( $this->isSpecialPage() ) {
2328                         return array();
2329                 }
2330
2331                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2332
2333                 if ( $this->getNamespace() != NS_FILE ) {
2334                         # Remove the upload restriction for non-file titles
2335                         $types = array_diff( $types, array( 'upload' ) );
2336                 }
2337
2338                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2339
2340                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2341                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2342
2343                 return $types;
2344         }
2345
2346         /**
2347          * Is this title subject to title protection?
2348          * Title protection is the one applied against creation of such title.
2349          *
2350          * @return Mixed An associative array representing any existent title
2351          *   protection, or false if there's none.
2352          */
2353         private function getTitleProtection() {
2354                 // Can't protect pages in special namespaces
2355                 if ( $this->getNamespace() < 0 ) {
2356                         return false;
2357                 }
2358
2359                 // Can't protect pages that exist.
2360                 if ( $this->exists() ) {
2361                         return false;
2362                 }
2363
2364                 if ( !isset( $this->mTitleProtection ) ) {
2365                         $dbr = wfGetDB( DB_SLAVE );
2366                         $res = $dbr->select(
2367                                 'protected_titles',
2368                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2369                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2370                                 __METHOD__
2371                         );
2372
2373                         // fetchRow returns false if there are no rows.
2374                         $this->mTitleProtection = $dbr->fetchRow( $res );
2375                 }
2376                 return $this->mTitleProtection;
2377         }
2378
2379         /**
2380          * Update the title protection status
2381          *
2382          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2383          * @param $create_perm String Permission required for creation
2384          * @param string $reason Reason for protection
2385          * @param string $expiry Expiry timestamp
2386          * @return boolean true
2387          */
2388         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2389                 wfDeprecated( __METHOD__, '1.19' );
2390
2391                 global $wgUser;
2392
2393                 $limit = array( 'create' => $create_perm );
2394                 $expiry = array( 'create' => $expiry );
2395
2396                 $page = WikiPage::factory( $this );
2397                 $cascade = false;
2398                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2399
2400                 return $status->isOK();
2401         }
2402
2403         /**
2404          * Remove any title protection due to page existing
2405          */
2406         public function deleteTitleProtection() {
2407                 $dbw = wfGetDB( DB_MASTER );
2408
2409                 $dbw->delete(
2410                         'protected_titles',
2411                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2412                         __METHOD__
2413                 );
2414                 $this->mTitleProtection = false;
2415         }
2416
2417         /**
2418          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2419          *
2420          * @param string $action Action to check (default: edit)
2421          * @return Bool
2422          */
2423         public function isSemiProtected( $action = 'edit' ) {
2424                 if ( $this->exists() ) {
2425                         $restrictions = $this->getRestrictions( $action );
2426                         if ( count( $restrictions ) > 0 ) {
2427                                 foreach ( $restrictions as $restriction ) {
2428                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2429                                                 return false;
2430                                         }
2431                                 }
2432                         } else {
2433                                 # Not protected
2434                                 return false;
2435                         }
2436                         return true;
2437                 } else {
2438                         # If it doesn't exist, it can't be protected
2439                         return false;
2440                 }
2441         }
2442
2443         /**
2444          * Does the title correspond to a protected article?
2445          *
2446          * @param string $action the action the page is protected from,
2447          * by default checks all actions.
2448          * @return Bool
2449          */
2450         public function isProtected( $action = '' ) {
2451                 global $wgRestrictionLevels;
2452
2453                 $restrictionTypes = $this->getRestrictionTypes();
2454
2455                 # Special pages have inherent protection
2456                 if ( $this->isSpecialPage() ) {
2457                         return true;
2458                 }
2459
2460                 # Check regular protection levels
2461                 foreach ( $restrictionTypes as $type ) {
2462                         if ( $action == $type || $action == '' ) {
2463                                 $r = $this->getRestrictions( $type );
2464                                 foreach ( $wgRestrictionLevels as $level ) {
2465                                         if ( in_array( $level, $r ) && $level != '' ) {
2466                                                 return true;
2467                                         }
2468                                 }
2469                         }
2470                 }
2471
2472                 return false;
2473         }
2474
2475         /**
2476          * Determines if $user is unable to edit this page because it has been protected
2477          * by $wgNamespaceProtection.
2478          *
2479          * @param $user User object to check permissions
2480          * @return Bool
2481          */
2482         public function isNamespaceProtected( User $user ) {
2483                 global $wgNamespaceProtection;
2484
2485                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2486                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2487                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2488                                         return true;
2489                                 }
2490                         }
2491                 }
2492                 return false;
2493         }
2494
2495         /**
2496          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2497          *
2498          * @return Bool If the page is subject to cascading restrictions.
2499          */
2500         public function isCascadeProtected() {
2501                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2502                 return ( $sources > 0 );
2503         }
2504
2505         /**
2506          * Cascading protection: Get the source of any cascading restrictions on this page.
2507          *
2508          * @param bool $getPages Whether or not to retrieve the actual pages
2509          *        that the restrictions have come from.
2510          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2511          *     have come, false for none, or true if such restrictions exist, but $getPages
2512          *     was not set.  The restriction array is an array of each type, each of which
2513          *     contains a array of unique groups.
2514          */
2515         public function getCascadeProtectionSources( $getPages = true ) {
2516                 global $wgContLang;
2517                 $pagerestrictions = array();
2518
2519                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2520                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2521                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2522                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2523                 }
2524
2525                 wfProfileIn( __METHOD__ );
2526
2527                 $dbr = wfGetDB( DB_SLAVE );
2528
2529                 if ( $this->getNamespace() == NS_FILE ) {
2530                         $tables = array( 'imagelinks', 'page_restrictions' );
2531                         $where_clauses = array(
2532                                 'il_to' => $this->getDBkey(),
2533                                 'il_from=pr_page',
2534                                 'pr_cascade' => 1
2535                         );
2536                 } else {
2537                         $tables = array( 'templatelinks', 'page_restrictions' );
2538                         $where_clauses = array(
2539                                 'tl_namespace' => $this->getNamespace(),
2540                                 'tl_title' => $this->getDBkey(),
2541                                 'tl_from=pr_page',
2542                                 'pr_cascade' => 1
2543                         );
2544                 }
2545
2546                 if ( $getPages ) {
2547                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2548                                 'pr_expiry', 'pr_type', 'pr_level' );
2549                         $where_clauses[] = 'page_id=pr_page';
2550                         $tables[] = 'page';
2551                 } else {
2552                         $cols = array( 'pr_expiry' );
2553                 }
2554
2555                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2556
2557                 $sources = $getPages ? array() : false;
2558                 $now = wfTimestampNow();
2559                 $purgeExpired = false;
2560
2561                 foreach ( $res as $row ) {
2562                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2563                         if ( $expiry > $now ) {
2564                                 if ( $getPages ) {
2565                                         $page_id = $row->pr_page;
2566                                         $page_ns = $row->page_namespace;
2567                                         $page_title = $row->page_title;
2568                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2569                                         # Add groups needed for each restriction type if its not already there
2570                                         # Make sure this restriction type still exists
2571
2572                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2573                                                 $pagerestrictions[$row->pr_type] = array();
2574                                         }
2575
2576                                         if (
2577                                                 isset( $pagerestrictions[$row->pr_type] )
2578                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2579                                         ) {
2580                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2581                                         }
2582                                 } else {
2583                                         $sources = true;
2584                                 }
2585                         } else {
2586                                 // Trigger lazy purge of expired restrictions from the db
2587                                 $purgeExpired = true;
2588                         }
2589                 }
2590                 if ( $purgeExpired ) {
2591                         Title::purgeExpiredRestrictions();
2592                 }
2593
2594                 if ( $getPages ) {
2595                         $this->mCascadeSources = $sources;
2596                         $this->mCascadingRestrictions = $pagerestrictions;
2597                 } else {
2598                         $this->mHasCascadingRestrictions = $sources;
2599                 }
2600
2601                 wfProfileOut( __METHOD__ );
2602                 return array( $sources, $pagerestrictions );
2603         }
2604
2605         /**
2606          * Accessor/initialisation for mRestrictions
2607          *
2608          * @param string $action action that permission needs to be checked for
2609          * @return Array of Strings the array of groups allowed to edit this article
2610          */
2611         public function getRestrictions( $action ) {
2612                 if ( !$this->mRestrictionsLoaded ) {
2613                         $this->loadRestrictions();
2614                 }
2615                 return isset( $this->mRestrictions[$action] )
2616                                 ? $this->mRestrictions[$action]
2617                                 : array();
2618         }
2619
2620         /**
2621          * Get the expiry time for the restriction against a given action
2622          *
2623          * @param $action
2624          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2625          *     or not protected at all, or false if the action is not recognised.
2626          */
2627         public function getRestrictionExpiry( $action ) {
2628                 if ( !$this->mRestrictionsLoaded ) {
2629                         $this->loadRestrictions();
2630                 }
2631                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2632         }
2633
2634         /**
2635          * Returns cascading restrictions for the current article
2636          *
2637          * @return Boolean
2638          */
2639         function areRestrictionsCascading() {
2640                 if ( !$this->mRestrictionsLoaded ) {
2641                         $this->loadRestrictions();
2642                 }
2643
2644                 return $this->mCascadeRestriction;
2645         }
2646
2647         /**
2648          * Loads a string into mRestrictions array
2649          *
2650          * @param $res Resource restrictions as an SQL result.
2651          * @param string $oldFashionedRestrictions comma-separated list of page
2652          *        restrictions from page table (pre 1.10)
2653          */
2654         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2655                 $rows = array();
2656
2657                 foreach ( $res as $row ) {
2658                         $rows[] = $row;
2659                 }
2660
2661                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2662         }
2663
2664         /**
2665          * Compiles list of active page restrictions from both page table (pre 1.10)
2666          * and page_restrictions table for this existing page.
2667          * Public for usage by LiquidThreads.
2668          *
2669          * @param array $rows of db result objects
2670          * @param string $oldFashionedRestrictions comma-separated list of page
2671          *        restrictions from page table (pre 1.10)
2672          */
2673         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2674                 global $wgContLang;
2675                 $dbr = wfGetDB( DB_SLAVE );
2676
2677                 $restrictionTypes = $this->getRestrictionTypes();
2678
2679                 foreach ( $restrictionTypes as $type ) {
2680                         $this->mRestrictions[$type] = array();
2681                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2682                 }
2683
2684                 $this->mCascadeRestriction = false;
2685
2686                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2687
2688                 if ( $oldFashionedRestrictions === null ) {
2689                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2690                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2691                 }
2692
2693                 if ( $oldFashionedRestrictions != '' ) {
2694
2695                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2696                                 $temp = explode( '=', trim( $restrict ) );
2697                                 if ( count( $temp ) == 1 ) {
2698                                         // old old format should be treated as edit/move restriction
2699                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2700                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2701                                 } else {
2702                                         $restriction = trim( $temp[1] );
2703                                         if ( $restriction != '' ) { //some old entries are empty
2704                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2705                                         }
2706                                 }
2707                         }
2708
2709                         $this->mOldRestrictions = true;
2710
2711                 }
2712
2713                 if ( count( $rows ) ) {
2714                         # Current system - load second to make them override.
2715                         $now = wfTimestampNow();
2716                         $purgeExpired = false;
2717
2718                         # Cycle through all the restrictions.
2719                         foreach ( $rows as $row ) {
2720
2721                                 // Don't take care of restrictions types that aren't allowed
2722                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2723                                         continue;
2724                                 }
2725
2726                                 // This code should be refactored, now that it's being used more generally,
2727                                 // But I don't really see any harm in leaving it in Block for now -werdna
2728                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2729
2730                                 // Only apply the restrictions if they haven't expired!
2731                                 if ( !$expiry || $expiry > $now ) {
2732                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2733                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2734
2735                                         $this->mCascadeRestriction |= $row->pr_cascade;
2736                                 } else {
2737                                         // Trigger a lazy purge of expired restrictions
2738                                         $purgeExpired = true;
2739                                 }
2740                         }
2741
2742                         if ( $purgeExpired ) {
2743                                 Title::purgeExpiredRestrictions();
2744                         }
2745                 }
2746
2747                 $this->mRestrictionsLoaded = true;
2748         }
2749
2750         /**
2751          * Load restrictions from the page_restrictions table
2752          *
2753          * @param string $oldFashionedRestrictions comma-separated list of page
2754          *        restrictions from page table (pre 1.10)
2755          */
2756         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2757                 global $wgContLang;
2758                 if ( !$this->mRestrictionsLoaded ) {
2759                         if ( $this->exists() ) {
2760                                 $dbr = wfGetDB( DB_SLAVE );
2761
2762                                 $res = $dbr->select(
2763                                         'page_restrictions',
2764                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2765                                         array( 'pr_page' => $this->getArticleID() ),
2766                                         __METHOD__
2767                                 );
2768
2769                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2770                         } else {
2771                                 $title_protection = $this->getTitleProtection();
2772
2773                                 if ( $title_protection ) {
2774                                         $now = wfTimestampNow();
2775                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2776
2777                                         if ( !$expiry || $expiry > $now ) {
2778                                                 // Apply the restrictions
2779                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2780                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2781                                         } else { // Get rid of the old restrictions
2782                                                 Title::purgeExpiredRestrictions();
2783                                                 $this->mTitleProtection = false;
2784                                         }
2785                                 } else {
2786                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2787                                 }
2788                                 $this->mRestrictionsLoaded = true;
2789                         }
2790                 }
2791         }
2792
2793         /**
2794          * Flush the protection cache in this object and force reload from the database.
2795          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2796          */
2797         public function flushRestrictions() {
2798                 $this->mRestrictionsLoaded = false;
2799                 $this->mTitleProtection = null;
2800         }
2801
2802         /**
2803          * Purge expired restrictions from the page_restrictions table
2804          */
2805         static function purgeExpiredRestrictions() {
2806                 if ( wfReadOnly() ) {
2807                         return;
2808                 }
2809
2810                 $dbw = wfGetDB( DB_MASTER );
2811                 $dbw->delete(
2812                         'page_restrictions',
2813                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2814                         __METHOD__
2815                 );
2816
2817                 $dbw->delete(
2818                         'protected_titles',
2819                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2820                         __METHOD__
2821                 );
2822         }
2823
2824         /**
2825          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2826          *
2827          * @return Bool
2828          */
2829         public function hasSubpages() {
2830                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2831                         # Duh
2832                         return false;
2833                 }
2834
2835                 # We dynamically add a member variable for the purpose of this method
2836                 # alone to cache the result.  There's no point in having it hanging
2837                 # around uninitialized in every Title object; therefore we only add it
2838                 # if needed and don't declare it statically.
2839                 if ( isset( $this->mHasSubpages ) ) {
2840                         return $this->mHasSubpages;
2841                 }
2842
2843                 $subpages = $this->getSubpages( 1 );
2844                 if ( $subpages instanceof TitleArray ) {
2845                         return $this->mHasSubpages = (bool)$subpages->count();
2846                 }
2847                 return $this->mHasSubpages = false;
2848         }
2849
2850         /**
2851          * Get all subpages of this page.
2852          *
2853          * @param int $limit maximum number of subpages to fetch; -1 for no limit
2854          * @return mixed TitleArray, or empty array if this page's namespace
2855          *  doesn't allow subpages
2856          */
2857         public function getSubpages( $limit = -1 ) {
2858                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2859                         return array();
2860                 }
2861
2862                 $dbr = wfGetDB( DB_SLAVE );
2863                 $conds['page_namespace'] = $this->getNamespace();
2864                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2865                 $options = array();
2866                 if ( $limit > -1 ) {
2867                         $options['LIMIT'] = $limit;
2868                 }
2869                 return $this->mSubpages = TitleArray::newFromResult(
2870                         $dbr->select( 'page',
2871                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2872                                 $conds,
2873                                 __METHOD__,
2874                                 $options
2875                         )
2876                 );
2877         }
2878
2879         /**
2880          * Is there a version of this page in the deletion archive?
2881          *
2882          * @return Int the number of archived revisions
2883          */
2884         public function isDeleted() {
2885                 if ( $this->getNamespace() < 0 ) {
2886                         $n = 0;
2887                 } else {
2888                         $dbr = wfGetDB( DB_SLAVE );
2889
2890                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2891                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2892                                 __METHOD__
2893                         );
2894                         if ( $this->getNamespace() == NS_FILE ) {
2895                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2896                                         array( 'fa_name' => $this->getDBkey() ),
2897                                         __METHOD__
2898                                 );
2899                         }
2900                 }
2901                 return (int)$n;
2902         }
2903
2904         /**
2905          * Is there a version of this page in the deletion archive?
2906          *
2907          * @return Boolean
2908          */
2909         public function isDeletedQuick() {
2910                 if ( $this->getNamespace() < 0 ) {
2911                         return false;
2912                 }
2913                 $dbr = wfGetDB( DB_SLAVE );
2914                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2915                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2916                         __METHOD__
2917                 );
2918                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2919                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2920                                 array( 'fa_name' => $this->getDBkey() ),
2921                                 __METHOD__
2922                         );
2923                 }
2924                 return $deleted;
2925         }
2926
2927         /**
2928          * Get the article ID for this Title from the link cache,
2929          * adding it if necessary
2930          *
2931          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select
2932          *  for update
2933          * @return Int the ID
2934          */
2935         public function getArticleID( $flags = 0 ) {
2936                 if ( $this->getNamespace() < 0 ) {
2937                         return $this->mArticleID = 0;
2938                 }
2939                 $linkCache = LinkCache::singleton();
2940                 if ( $flags & self::GAID_FOR_UPDATE ) {
2941                         $oldUpdate = $linkCache->forUpdate( true );
2942                         $linkCache->clearLink( $this );
2943                         $this->mArticleID = $linkCache->addLinkObj( $this );
2944                         $linkCache->forUpdate( $oldUpdate );
2945                 } else {
2946                         if ( -1 == $this->mArticleID ) {
2947                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2948                         }
2949                 }
2950                 return $this->mArticleID;
2951         }
2952
2953         /**
2954          * Is this an article that is a redirect page?
2955          * Uses link cache, adding it if necessary
2956          *
2957          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
2958          * @return Bool
2959          */
2960         public function isRedirect( $flags = 0 ) {
2961                 if ( !is_null( $this->mRedirect ) ) {
2962                         return $this->mRedirect;
2963                 }
2964                 # Calling getArticleID() loads the field from cache as needed
2965                 if ( !$this->getArticleID( $flags ) ) {
2966                         return $this->mRedirect = false;
2967                 }
2968
2969                 $linkCache = LinkCache::singleton();
2970                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2971                 if ( $cached === null ) {
2972                         // TODO: check the assumption that the cache actually knows about this title
2973                         // and handle this, such as get the title from the database.
2974                         // See https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2975                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2976                         wfDebug( wfBacktrace() );
2977                 }
2978
2979                 $this->mRedirect = (bool)$cached;
2980
2981                 return $this->mRedirect;
2982         }
2983
2984         /**
2985          * What is the length of this page?
2986          * Uses link cache, adding it if necessary
2987          *
2988          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
2989          * @return Int
2990          */
2991         public function getLength( $flags = 0 ) {
2992                 if ( $this->mLength != -1 ) {
2993                         return $this->mLength;
2994                 }
2995                 # Calling getArticleID() loads the field from cache as needed
2996                 if ( !$this->getArticleID( $flags ) ) {
2997                         return $this->mLength = 0;
2998                 }
2999                 $linkCache = LinkCache::singleton();
3000                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3001                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
3002                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
3003                         #      as a stop gap, perhaps log this, but don't throw an exception?
3004                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
3005                         wfDebug( wfBacktrace() );
3006                 }
3007
3008                 $this->mLength = intval( $cached );
3009
3010                 return $this->mLength;
3011         }
3012
3013         /**
3014          * What is the page_latest field for this page?
3015          *
3016          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3017          * @throws MWException
3018          * @return Int or 0 if the page doesn't exist
3019          */
3020         public function getLatestRevID( $flags = 0 ) {
3021                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3022                         return intval( $this->mLatestID );
3023                 }
3024                 # Calling getArticleID() loads the field from cache as needed
3025                 if ( !$this->getArticleID( $flags ) ) {
3026                         return $this->mLatestID = 0;
3027                 }
3028                 $linkCache = LinkCache::singleton();
3029                 $linkCache->addLinkObj( $this );
3030                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3031                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
3032                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
3033                         #      as a stop gap, perhaps log this, but don't throw an exception?
3034                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
3035                 }
3036
3037                 $this->mLatestID = intval( $cached );
3038
3039                 return $this->mLatestID;
3040         }
3041
3042         /**
3043          * This clears some fields in this object, and clears any associated
3044          * keys in the "bad links" section of the link cache.
3045          *
3046          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3047          * loading of the new page_id. It's also called from
3048          * WikiPage::doDeleteArticleReal()
3049          *
3050          * @param int $newid the new Article ID
3051          */
3052         public function resetArticleID( $newid ) {
3053                 $linkCache = LinkCache::singleton();
3054                 $linkCache->clearLink( $this );
3055
3056                 if ( $newid === false ) {
3057                         $this->mArticleID = -1;
3058                 } else {
3059                         $this->mArticleID = intval( $newid );
3060                 }
3061                 $this->mRestrictionsLoaded = false;
3062                 $this->mRestrictions = array();
3063                 $this->mRedirect = null;
3064                 $this->mLength = -1;
3065                 $this->mLatestID = false;
3066                 $this->mContentModel = false;
3067                 $this->mEstimateRevisions = null;
3068         }
3069
3070         /**
3071          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3072          *
3073          * @param string $text containing title to capitalize
3074          * @param int $ns namespace index, defaults to NS_MAIN
3075          * @return String containing capitalized title
3076          */
3077         public static function capitalize( $text, $ns = NS_MAIN ) {
3078                 global $wgContLang;
3079
3080                 if ( MWNamespace::isCapitalized( $ns ) ) {
3081                         return $wgContLang->ucfirst( $text );
3082                 } else {
3083                         return $text;
3084                 }
3085         }
3086
3087         /**
3088          * Secure and split - main initialisation function for this object
3089          *
3090          * Assumes that mDbkeyform has been set, and is urldecoded
3091          * and uses underscores, but not otherwise munged.  This function
3092          * removes illegal characters, splits off the interwiki and
3093          * namespace prefixes, sets the other forms, and canonicalizes
3094          * everything.
3095          *
3096          * @return Bool true on success
3097          */
3098         private function secureAndSplit() {
3099                 global $wgContLang, $wgLocalInterwiki;
3100
3101                 # Initialisation
3102                 $this->mInterwiki = $this->mFragment = '';
3103                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3104
3105                 $dbkey = $this->mDbkeyform;
3106
3107                 # Strip Unicode bidi override characters.
3108                 # Sometimes they slip into cut-n-pasted page titles, where the
3109                 # override chars get included in list displays.
3110                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3111
3112                 # Clean up whitespace
3113                 # Note: use of the /u option on preg_replace here will cause
3114                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3115                 # conveniently disabling them.
3116                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3117                 $dbkey = trim( $dbkey, '_' );
3118
3119                 if ( $dbkey == '' ) {
3120                         return false;
3121                 }
3122
3123                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3124                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3125                         return false;
3126                 }
3127
3128                 $this->mDbkeyform = $dbkey;
3129
3130                 # Initial colon indicates main namespace rather than specified default
3131                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3132                 if ( ':' == $dbkey[0] ) {
3133                         $this->mNamespace = NS_MAIN;
3134                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3135                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3136                 }
3137
3138                 # Namespace or interwiki prefix
3139                 $firstPass = true;
3140                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3141                 do {
3142                         $m = array();
3143                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3144                                 $p = $m[1];
3145                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3146                                         # Ordinary namespace
3147                                         $dbkey = $m[2];
3148                                         $this->mNamespace = $ns;
3149                                         # For Talk:X pages, check if X has a "namespace" prefix
3150                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3151                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3152                                                         # Disallow Talk:File:x type titles...
3153                                                         return false;
3154                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3155                                                         # Disallow Talk:Interwiki:x type titles...
3156                                                         return false;
3157                                                 }
3158                                         }
3159                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3160                                         if ( !$firstPass ) {
3161                                                 # Can't make a local interwiki link to an interwiki link.
3162                                                 # That's just crazy!
3163                                                 return false;
3164                                         }
3165
3166                                         # Interwiki link
3167                                         $dbkey = $m[2];
3168                                         $this->mInterwiki = $wgContLang->lc( $p );
3169
3170                                         # Redundant interwiki prefix to the local wiki
3171                                         if ( $wgLocalInterwiki !== false
3172                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3173                                         {
3174                                                 if ( $dbkey == '' ) {
3175                                                         # Can't have an empty self-link
3176                                                         return false;
3177                                                 }
3178                                                 $this->mInterwiki = '';
3179                                                 $firstPass = false;
3180                                                 # Do another namespace split...
3181                                                 continue;
3182                                         }
3183
3184                                         # If there's an initial colon after the interwiki, that also
3185                                         # resets the default namespace
3186                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3187                                                 $this->mNamespace = NS_MAIN;
3188                                                 $dbkey = substr( $dbkey, 1 );
3189                                         }
3190                                 }
3191                                 # If there's no recognized interwiki or namespace,
3192                                 # then let the colon expression be part of the title.
3193                         }
3194                         break;
3195                 } while ( true );
3196
3197                 # We already know that some pages won't be in the database!
3198                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3199                         $this->mArticleID = 0;
3200                 }
3201                 $fragment = strstr( $dbkey, '#' );
3202                 if ( false !== $fragment ) {
3203                         $this->setFragment( $fragment );
3204                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3205                         # remove whitespace again: prevents "Foo_bar_#"
3206                         # becoming "Foo_bar_"
3207                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3208                 }
3209
3210                 # Reject illegal characters.
3211                 $rxTc = self::getTitleInvalidRegex();
3212                 if ( preg_match( $rxTc, $dbkey ) ) {
3213                         return false;
3214                 }
3215
3216                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3217                 # reachable due to the way web browsers deal with 'relative' URLs.
3218                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3219                 if (
3220                         strpos( $dbkey, '.' ) !== false &&
3221                         (
3222                                 $dbkey === '.' || $dbkey === '..' ||
3223                                 strpos( $dbkey, './' ) === 0 ||
3224                                 strpos( $dbkey, '../' ) === 0 ||
3225                                 strpos( $dbkey, '/./' ) !== false ||
3226                                 strpos( $dbkey, '/../' ) !== false ||
3227                                 substr( $dbkey, -2 ) == '/.' ||
3228                                 substr( $dbkey, -3 ) == '/..'
3229                         )
3230                 ) {
3231                         return false;
3232                 }
3233
3234                 # Magic tilde sequences? Nu-uh!
3235                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3236                         return false;
3237                 }
3238
3239                 # Limit the size of titles to 255 bytes. This is typically the size of the
3240                 # underlying database field. We make an exception for special pages, which
3241                 # don't need to be stored in the database, and may edge over 255 bytes due
3242                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3243                 if (
3244                         ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 )
3245                         || strlen( $dbkey ) > 512
3246                 ) {
3247                         return false;
3248                 }
3249
3250                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3251                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3252                 # other site might be case-sensitive.
3253                 $this->mUserCaseDBKey = $dbkey;
3254                 if ( $this->mInterwiki == '' ) {
3255                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3256                 }
3257
3258                 # Can't make a link to a namespace alone... "empty" local links can only be
3259                 # self-links with a fragment identifier.
3260                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3261                         return false;
3262                 }
3263
3264                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3265                 // IP names are not allowed for accounts, and can only be referring to
3266                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3267                 // there are numerous ways to present the same IP. Having sp:contribs scan
3268                 // them all is silly and having some show the edits and others not is
3269                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3270                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3271                         ? IP::sanitizeIP( $dbkey )
3272                         : $dbkey;
3273
3274                 // Any remaining initial :s are illegal.
3275                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3276                         return false;
3277                 }
3278
3279                 # Fill fields
3280                 $this->mDbkeyform = $dbkey;
3281                 $this->mUrlform = wfUrlencode( $dbkey );
3282
3283                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3284
3285                 return true;
3286         }
3287
3288         /**
3289          * Get an array of Title objects linking to this Title
3290          * Also stores the IDs in the link cache.
3291          *
3292          * WARNING: do not use this function on arbitrary user-supplied titles!
3293          * On heavily-used templates it will max out the memory.
3294          *
3295          * @param array $options may be FOR UPDATE
3296          * @param string $table table name
3297          * @param string $prefix fields prefix
3298          * @return Array of Title objects linking here
3299          */
3300         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3301                 if ( count( $options ) > 0 ) {
3302                         $db = wfGetDB( DB_MASTER );
3303                 } else {
3304                         $db = wfGetDB( DB_SLAVE );
3305                 }
3306
3307                 $res = $db->select(
3308                         array( 'page', $table ),
3309                         self::getSelectFields(),
3310                         array(
3311                                 "{$prefix}_from=page_id",
3312                                 "{$prefix}_namespace" => $this->getNamespace(),
3313                                 "{$prefix}_title" => $this->getDBkey() ),
3314                         __METHOD__,
3315                         $options
3316                 );
3317
3318                 $retVal = array();
3319                 if ( $res->numRows() ) {
3320                         $linkCache = LinkCache::singleton();
3321                         foreach ( $res as $row ) {
3322                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3323                                 if ( $titleObj ) {
3324                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3325                                         $retVal[] = $titleObj;
3326                                 }
3327                         }
3328                 }
3329                 return $retVal;
3330         }
3331
3332         /**
3333          * Get an array of Title objects using this Title as a template
3334          * Also stores the IDs in the link cache.
3335          *
3336          * WARNING: do not use this function on arbitrary user-supplied titles!
3337          * On heavily-used templates it will max out the memory.
3338          *
3339          * @param array $options may be FOR UPDATE
3340          * @return Array of Title the Title objects linking here
3341          */
3342         public function getTemplateLinksTo( $options = array() ) {
3343                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3344         }
3345
3346         /**
3347          * Get an array of Title objects linked from this Title
3348          * Also stores the IDs in the link cache.
3349          *
3350          * WARNING: do not use this function on arbitrary user-supplied titles!
3351          * On heavily-used templates it will max out the memory.
3352          *
3353          * @param array $options may be FOR UPDATE
3354          * @param string $table table name
3355          * @param string $prefix fields prefix
3356          * @return Array of Title objects linking here
3357          */
3358         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3359                 global $wgContentHandlerUseDB;
3360
3361                 $id = $this->getArticleID();
3362
3363                 # If the page doesn't exist; there can't be any link from this page
3364                 if ( !$id ) {
3365                         return array();
3366                 }
3367
3368                 if ( count( $options ) > 0 ) {
3369                         $db = wfGetDB( DB_MASTER );
3370                 } else {
3371                         $db = wfGetDB( DB_SLAVE );
3372                 }
3373
3374                 $namespaceFiled = "{$prefix}_namespace";
3375                 $titleField = "{$prefix}_title";
3376
3377                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3378                 if ( $wgContentHandlerUseDB ) {
3379                         $fields[] = 'page_content_model';
3380                 }
3381
3382                 $res = $db->select(
3383                         array( $table, 'page' ),
3384                         $fields,
3385                         array( "{$prefix}_from" => $id ),
3386                         __METHOD__,
3387                         $options,
3388                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3389                 );
3390
3391                 $retVal = array();
3392                 if ( $res->numRows() ) {
3393                         $linkCache = LinkCache::singleton();
3394                         foreach ( $res as $row ) {
3395                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3396                                 if ( $titleObj ) {
3397                                         if ( $row->page_id ) {
3398                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3399                                         } else {
3400                                                 $linkCache->addBadLinkObj( $titleObj );
3401                                         }
3402                                         $retVal[] = $titleObj;
3403                                 }
3404                         }
3405                 }
3406                 return $retVal;
3407         }
3408
3409         /**
3410          * Get an array of Title objects used on this Title as a template
3411          * Also stores the IDs in the link cache.
3412          *
3413          * WARNING: do not use this function on arbitrary user-supplied titles!
3414          * On heavily-used templates it will max out the memory.
3415          *
3416          * @param array $options may be FOR UPDATE
3417          * @return Array of Title the Title objects used here
3418          */
3419         public function getTemplateLinksFrom( $options = array() ) {
3420                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3421         }
3422
3423         /**
3424          * Get an array of Title objects referring to non-existent articles linked from this page
3425          *
3426          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3427          * @return Array of Title the Title objects
3428          */
3429         public function getBrokenLinksFrom() {
3430                 if ( $this->getArticleID() == 0 ) {
3431                         # All links from article ID 0 are false positives
3432                         return array();
3433                 }
3434
3435                 $dbr = wfGetDB( DB_SLAVE );
3436                 $res = $dbr->select(
3437                         array( 'page', 'pagelinks' ),
3438                         array( 'pl_namespace', 'pl_title' ),
3439                         array(
3440                                 'pl_from' => $this->getArticleID(),
3441                                 'page_namespace IS NULL'
3442                         ),
3443                         __METHOD__, array(),
3444                         array(
3445                                 'page' => array(
3446                                         'LEFT JOIN',
3447                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3448                                 )
3449                         )
3450                 );
3451
3452                 $retVal = array();
3453                 foreach ( $res as $row ) {
3454                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3455                 }
3456                 return $retVal;
3457         }
3458
3459         /**
3460          * Get a list of URLs to purge from the Squid cache when this
3461          * page changes
3462          *
3463          * @return Array of String the URLs
3464          */
3465         public function getSquidURLs() {
3466                 $urls = array(
3467                         $this->getInternalURL(),
3468                         $this->getInternalURL( 'action=history' )
3469                 );
3470
3471                 $pageLang = $this->getPageLanguage();
3472                 if ( $pageLang->hasVariants() ) {
3473                         $variants = $pageLang->getVariants();
3474                         foreach ( $variants as $vCode ) {
3475                                 $urls[] = $this->getInternalURL( '', $vCode );
3476                         }
3477                 }
3478
3479                 return $urls;
3480         }
3481
3482         /**
3483          * Purge all applicable Squid URLs
3484          */
3485         public function purgeSquid() {
3486                 global $wgUseSquid;
3487                 if ( $wgUseSquid ) {
3488                         $urls = $this->getSquidURLs();
3489                         $u = new SquidUpdate( $urls );
3490                         $u->doUpdate();
3491                 }
3492         }
3493
3494         /**
3495          * Move this page without authentication
3496          *
3497          * @param $nt Title the new page Title
3498          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3499          */
3500         public function moveNoAuth( &$nt ) {
3501                 return $this->moveTo( $nt, false );
3502         }
3503
3504         /**
3505          * Check whether a given move operation would be valid.
3506          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3507          *
3508          * @param $nt Title the new title
3509          * @param bool $auth indicates whether $wgUser's permissions
3510          *  should be checked
3511          * @param string $reason is the log summary of the move, used for spam checking
3512          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3513          */
3514         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3515                 global $wgUser, $wgContentHandlerUseDB;
3516
3517                 $errors = array();
3518                 if ( !$nt ) {
3519                         // Normally we'd add this to $errors, but we'll get
3520                         // lots of syntax errors if $nt is not an object
3521                         return array( array( 'badtitletext' ) );
3522                 }
3523                 if ( $this->equals( $nt ) ) {
3524                         $errors[] = array( 'selfmove' );
3525                 }
3526                 if ( !$this->isMovable() ) {
3527                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3528                 }
3529                 if ( $nt->getInterwiki() != '' ) {
3530                         $errors[] = array( 'immobile-target-namespace-iw' );
3531                 }
3532                 if ( !$nt->isMovable() ) {
3533                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3534                 }
3535
3536                 $oldid = $this->getArticleID();
3537                 $newid = $nt->getArticleID();
3538
3539                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3540                         $errors[] = array( 'articleexists' );
3541                 }
3542                 if (
3543                         ( $this->getDBkey() == '' ) ||
3544                         ( !$oldid ) ||
3545                         ( $nt->getDBkey() == '' )
3546                 ) {
3547                         $errors[] = array( 'badarticleerror' );
3548                 }
3549
3550                 // Content model checks
3551                 if ( !$wgContentHandlerUseDB &&
3552                                 $this->getContentModel() !== $nt->getContentModel() ) {
3553                         // can't move a page if that would change the page's content model
3554                         $errors[] = array(
3555                                 'bad-target-model',
3556                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3557                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3558                         );
3559                 }
3560
3561                 // Image-specific checks
3562                 if ( $this->getNamespace() == NS_FILE ) {
3563                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3564                 }
3565
3566                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3567                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3568                 }
3569
3570                 if ( $auth ) {
3571                         $errors = wfMergeErrorArrays( $errors,
3572                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3573                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3574                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3575                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3576                 }
3577
3578                 $match = EditPage::matchSummarySpamRegex( $reason );
3579                 if ( $match !== false ) {
3580                         // This is kind of lame, won't display nice
3581                         $errors[] = array( 'spamprotectiontext' );
3582                 }
3583
3584                 $err = null;
3585                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3586                         $errors[] = array( 'hookaborted', $err );
3587                 }
3588
3589                 # The move is allowed only if (1) the target doesn't exist, or
3590                 # (2) the target is a redirect to the source, and has no history
3591                 # (so we can undo bad moves right after they're done).
3592
3593                 if ( 0 != $newid ) { # Target exists; check for validity
3594                         if ( !$this->isValidMoveTarget( $nt ) ) {
3595                                 $errors[] = array( 'articleexists' );
3596                         }
3597                 } else {
3598                         $tp = $nt->getTitleProtection();
3599                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3600                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3601                                 $errors[] = array( 'cantmove-titleprotected' );
3602                         }
3603                 }
3604                 if ( empty( $errors ) ) {
3605                         return true;
3606                 }
3607                 return $errors;
3608         }
3609
3610         /**
3611          * Check if the requested move target is a valid file move target
3612          * @param Title $nt Target title
3613          * @return array List of errors
3614          */
3615         protected function validateFileMoveOperation( $nt ) {
3616                 global $wgUser;
3617
3618                 $errors = array();
3619
3620                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3621
3622                 $file = wfLocalFile( $this );
3623                 if ( $file->exists() ) {
3624                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3625                                 $errors[] = array( 'imageinvalidfilename' );
3626                         }
3627                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3628                                 $errors[] = array( 'imagetypemismatch' );
3629                         }
3630                 }
3631
3632                 if ( $nt->getNamespace() != NS_FILE ) {
3633                         $errors[] = array( 'imagenocrossnamespace' );
3634                         // From here we want to do checks on a file object, so if we can't
3635                         // create one, we must return.
3636                         return $errors;
3637                 }
3638
3639                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3640
3641                 $destFile = wfLocalFile( $nt );
3642                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3643                         $errors[] = array( 'file-exists-sharedrepo' );
3644                 }
3645
3646                 return $errors;
3647         }
3648
3649         /**
3650          * Move a title to a new location
3651          *
3652          * @param $nt Title the new title
3653          * @param bool $auth indicates whether $wgUser's permissions
3654          *  should be checked
3655          * @param string $reason the reason for the move
3656          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3657          *  Ignored if the user doesn't have the suppressredirect right.
3658          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3659          */
3660         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3661                 global $wgUser;
3662                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3663                 if ( is_array( $err ) ) {
3664                         // Auto-block user's IP if the account was "hard" blocked
3665                         $wgUser->spreadAnyEditBlock();
3666                         return $err;
3667                 }
3668                 // Check suppressredirect permission
3669                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3670                         $createRedirect = true;
3671                 }
3672
3673                 // If it is a file, move it first.
3674                 // It is done before all other moving stuff is done because it's hard to revert.
3675                 $dbw = wfGetDB( DB_MASTER );
3676                 if ( $this->getNamespace() == NS_FILE ) {
3677                         $file = wfLocalFile( $this );
3678                         if ( $file->exists() ) {
3679                                 $status = $file->move( $nt );
3680                                 if ( !$status->isOk() ) {
3681                                         return $status->getErrorsArray();
3682                                 }
3683                         }
3684                         // Clear RepoGroup process cache
3685                         RepoGroup::singleton()->clearCache( $this );
3686                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3687                 }
3688
3689                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3690                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3691                 $protected = $this->isProtected();
3692
3693                 // Do the actual move
3694                 $this->moveToInternal( $nt, $reason, $createRedirect );
3695
3696                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3697                 // cl_timestamp, which may disturb time-based lists on some sites.
3698                 $prefixes = $dbw->select(
3699                         'categorylinks',
3700                         array( 'cl_sortkey_prefix', 'cl_to' ),
3701                         array( 'cl_from' => $pageid ),
3702                         __METHOD__
3703                 );
3704                 foreach ( $prefixes as $prefixRow ) {
3705                         $prefix = $prefixRow->cl_sortkey_prefix;
3706                         $catTo = $prefixRow->cl_to;
3707                         $dbw->update( 'categorylinks',
3708                                 array(
3709                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3710                                                 $nt->getCategorySortkey( $prefix ) ),
3711                                         'cl_timestamp=cl_timestamp' ),
3712                                 array(
3713                                         'cl_from' => $pageid,
3714                                         'cl_to' => $catTo ),
3715                                 __METHOD__
3716                         );
3717                 }
3718
3719                 $redirid = $this->getArticleID();
3720
3721                 if ( $protected ) {
3722                         # Protect the redirect title as the title used to be...
3723                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3724                                 array(
3725                                         'pr_page' => $redirid,
3726                                         'pr_type' => 'pr_type',
3727                                         'pr_level' => 'pr_level',
3728                                         'pr_cascade' => 'pr_cascade',
3729                                         'pr_user' => 'pr_user',
3730                                         'pr_expiry' => 'pr_expiry'
3731                                 ),
3732                                 array( 'pr_page' => $pageid ),
3733                                 __METHOD__,
3734                                 array( 'IGNORE' )
3735                         );
3736                         # Update the protection log
3737                         $log = new LogPage( 'protect' );
3738                         $comment = wfMessage(
3739                                 'prot_1movedto2',
3740                                 $this->getPrefixedText(),
3741                                 $nt->getPrefixedText()
3742                         )->inContentLanguage()->text();
3743                         if ( $reason ) {
3744                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3745                         }
3746                         // @todo FIXME: $params?
3747                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3748                 }
3749
3750                 # Update watchlists
3751                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3752                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3753                 $oldtitle = $this->getDBkey();
3754                 $newtitle = $nt->getDBkey();
3755
3756                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3757                         WatchedItem::duplicateEntries( $this, $nt );
3758                 }
3759
3760                 $dbw->commit( __METHOD__ );
3761
3762                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3763                 return true;
3764         }
3765
3766         /**
3767          * Move page to a title which is either a redirect to the
3768          * source page or nonexistent
3769          *
3770          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3771          * @param string $reason The reason for the move
3772          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3773          *   if the user has the suppressredirect right
3774          * @throws MWException
3775          */
3776         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3777                 global $wgUser, $wgContLang;
3778
3779                 if ( $nt->exists() ) {
3780                         $moveOverRedirect = true;
3781                         $logType = 'move_redir';
3782                 } else {
3783                         $moveOverRedirect = false;
3784                         $logType = 'move';
3785                 }
3786
3787                 if ( $createRedirect ) {
3788                         $contentHandler = ContentHandler::getForTitle( $this );
3789                         $redirectContent = $contentHandler->makeRedirectContent( $nt );
3790
3791                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3792                 } else {
3793                         $redirectContent = null;
3794                 }
3795
3796                 $logEntry = new ManualLogEntry( 'move', $logType );
3797                 $logEntry->setPerformer( $wgUser );
3798                 $logEntry->setTarget( $this );
3799                 $logEntry->setComment( $reason );
3800                 $logEntry->setParameters( array(
3801                         '4::target' => $nt->getPrefixedText(),
3802                         '5::noredir' => $redirectContent ? '0': '1',
3803                 ) );
3804
3805                 $formatter = LogFormatter::newFromEntry( $logEntry );
3806                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3807                 $comment = $formatter->getPlainActionText();
3808                 if ( $reason ) {
3809                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3810                 }
3811                 # Truncate for whole multibyte characters.
3812                 $comment = $wgContLang->truncate( $comment, 255 );
3813
3814                 $oldid = $this->getArticleID();
3815
3816                 $dbw = wfGetDB( DB_MASTER );
3817
3818                 $newpage = WikiPage::factory( $nt );
3819
3820                 if ( $moveOverRedirect ) {
3821                         $newid = $nt->getArticleID();
3822
3823                         # Delete the old redirect. We don't save it to history since
3824                         # by definition if we've got here it's rather uninteresting.
3825                         # We have to remove it so that the next step doesn't trigger
3826                         # a conflict on the unique namespace+title index...
3827                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3828
3829                         $newpage->doDeleteUpdates( $newid );
3830                 }
3831
3832                 # Save a null revision in the page's history notifying of the move
3833                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3834                 if ( !is_object( $nullRevision ) ) {
3835                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3836                 }
3837
3838                 $nullRevision->insertOn( $dbw );
3839
3840                 # Change the name of the target page:
3841                 $dbw->update( 'page',
3842                         /* SET */ array(
3843                                 'page_namespace' => $nt->getNamespace(),
3844                                 'page_title' => $nt->getDBkey(),
3845                         ),
3846                         /* WHERE */ array( 'page_id' => $oldid ),
3847                         __METHOD__
3848                 );
3849
3850                 $this->resetArticleID( 0 );
3851                 $nt->resetArticleID( $oldid );
3852                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3853
3854                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3855
3856                 wfRunHooks( 'NewRevisionFromEditComplete',
3857                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3858
3859                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3860
3861                 if ( !$moveOverRedirect ) {
3862                         WikiPage::onArticleCreate( $nt );
3863                 }
3864
3865                 # Recreate the redirect, this time in the other direction.
3866                 if ( !$redirectContent ) {
3867                         WikiPage::onArticleDelete( $this );
3868                 } else {
3869                         $redirectArticle = WikiPage::factory( $this );
3870                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
3871                         $newid = $redirectArticle->insertOn( $dbw );
3872                         if ( $newid ) { // sanity
3873                                 $redirectRevision = new Revision( array(
3874                                         'title' => $this, // for determining the default content model
3875                                         'page' => $newid,
3876                                         'comment' => $comment,
3877                                         'content' => $redirectContent ) );
3878                                 $redirectRevision->insertOn( $dbw );
3879                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3880
3881                                 wfRunHooks( 'NewRevisionFromEditComplete',
3882                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3883
3884                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3885                         }
3886                 }
3887
3888                 # Log the move
3889                 $logid = $logEntry->insert();
3890                 $logEntry->publish( $logid );
3891         }
3892
3893         /**
3894          * Move this page's subpages to be subpages of $nt
3895          *
3896          * @param $nt Title Move target
3897          * @param bool $auth Whether $wgUser's permissions should be checked
3898          * @param string $reason The reason for the move
3899          * @param bool $createRedirect Whether to create redirects from the old subpages to
3900          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3901          * @return mixed array with old page titles as keys, and strings (new page titles) or
3902          *     arrays (errors) as values, or an error array with numeric indices if no pages
3903          *     were moved
3904          */
3905         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3906                 global $wgMaximumMovedPages;
3907                 // Check permissions
3908                 if ( !$this->userCan( 'move-subpages' ) ) {
3909                         return array( 'cant-move-subpages' );
3910                 }
3911                 // Do the source and target namespaces support subpages?
3912                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3913                         return array( 'namespace-nosubpages',
3914                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3915                 }
3916                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3917                         return array( 'namespace-nosubpages',
3918                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3919                 }
3920
3921                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3922                 $retval = array();
3923                 $count = 0;
3924                 foreach ( $subpages as $oldSubpage ) {
3925                         $count++;
3926                         if ( $count > $wgMaximumMovedPages ) {
3927                                 $retval[$oldSubpage->getPrefixedTitle()] =
3928                                                 array( 'movepage-max-pages',
3929                                                         $wgMaximumMovedPages );
3930                                 break;
3931                         }
3932
3933                         // We don't know whether this function was called before
3934                         // or after moving the root page, so check both
3935                         // $this and $nt
3936                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3937                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3938                         {
3939                                 // When moving a page to a subpage of itself,
3940                                 // don't move it twice
3941                                 continue;
3942                         }
3943                         $newPageName = preg_replace(
3944                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3945                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3946                                         $oldSubpage->getDBkey() );
3947                         if ( $oldSubpage->isTalkPage() ) {
3948                                 $newNs = $nt->getTalkPage()->getNamespace();
3949                         } else {
3950                                 $newNs = $nt->getSubjectPage()->getNamespace();
3951                         }
3952                         # Bug 14385: we need makeTitleSafe because the new page names may
3953                         # be longer than 255 characters.
3954                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3955
3956                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3957                         if ( $success === true ) {
3958                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3959                         } else {
3960                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3961                         }
3962                 }
3963                 return $retval;
3964         }
3965
3966         /**
3967          * Checks if this page is just a one-rev redirect.
3968          * Adds lock, so don't use just for light purposes.
3969          *
3970          * @return Bool
3971          */
3972         public function isSingleRevRedirect() {
3973                 global $wgContentHandlerUseDB;
3974
3975                 $dbw = wfGetDB( DB_MASTER );
3976
3977                 # Is it a redirect?
3978                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3979                 if ( $wgContentHandlerUseDB ) {
3980                         $fields[] = 'page_content_model';
3981                 }
3982
3983                 $row = $dbw->selectRow( 'page',
3984                         $fields,
3985                         $this->pageCond(),
3986                         __METHOD__,
3987                         array( 'FOR UPDATE' )
3988                 );
3989                 # Cache some fields we may want
3990                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3991                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3992                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3993                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
3994                 if ( !$this->mRedirect ) {
3995                         return false;
3996                 }
3997                 # Does the article have a history?
3998                 $row = $dbw->selectField( array( 'page', 'revision' ),
3999                         'rev_id',
4000                         array( 'page_namespace' => $this->getNamespace(),
4001                                 'page_title' => $this->getDBkey(),
4002                                 'page_id=rev_page',
4003                                 'page_latest != rev_id'
4004                         ),
4005                         __METHOD__,
4006                         array( 'FOR UPDATE' )
4007                 );
4008                 # Return true if there was no history
4009                 return ( $row === false );
4010         }
4011
4012         /**
4013          * Checks if $this can be moved to a given Title
4014          * - Selects for update, so don't call it unless you mean business
4015          *
4016          * @param $nt Title the new title to check
4017          * @return Bool
4018          */
4019         public function isValidMoveTarget( $nt ) {
4020                 # Is it an existing file?
4021                 if ( $nt->getNamespace() == NS_FILE ) {
4022                         $file = wfLocalFile( $nt );
4023                         if ( $file->exists() ) {
4024                                 wfDebug( __METHOD__ . ": file exists\n" );
4025                                 return false;
4026                         }
4027                 }
4028                 # Is it a redirect with no history?
4029                 if ( !$nt->isSingleRevRedirect() ) {
4030                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4031                         return false;
4032                 }
4033                 # Get the article text
4034                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4035                 if ( !is_object( $rev ) ) {
4036                         return false;
4037                 }
4038                 $content = $rev->getContent();
4039                 # Does the redirect point to the source?
4040                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4041                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4042
4043                 if ( $redirTitle ) {
4044                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4045                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4046                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4047                                 return false;
4048                         } else {
4049                                 return true;
4050                         }
4051                 } else {
4052                         # Fail safe (not a redirect after all. strange.)
4053                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4054                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4055                         return false;
4056                 }
4057         }
4058
4059         /**
4060          * Get categories to which this Title belongs and return an array of
4061          * categories' names.
4062          *
4063          * @return Array of parents in the form:
4064          *        $parent => $currentarticle
4065          */
4066         public function getParentCategories() {
4067                 global $wgContLang;
4068
4069                 $data = array();
4070
4071                 $titleKey = $this->getArticleID();
4072
4073                 if ( $titleKey === 0 ) {
4074                         return $data;
4075                 }
4076
4077                 $dbr = wfGetDB( DB_SLAVE );
4078
4079                 $res = $dbr->select(
4080                         'categorylinks',
4081                         'cl_to',
4082                         array( 'cl_from' => $titleKey ),
4083                         __METHOD__
4084                 );
4085
4086                 if ( $res->numRows() > 0 ) {
4087                         foreach ( $res as $row ) {
4088                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4089                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4090                         }
4091                 }
4092                 return $data;
4093         }
4094
4095         /**
4096          * Get a tree of parent categories
4097          *
4098          * @param array $children with the children in the keys, to check for circular refs
4099          * @return Array Tree of parent categories
4100          */
4101         public function getParentCategoryTree( $children = array() ) {
4102                 $stack = array();
4103                 $parents = $this->getParentCategories();
4104
4105                 if ( $parents ) {
4106                         foreach ( $parents as $parent => $current ) {
4107                                 if ( array_key_exists( $parent, $children ) ) {
4108                                         # Circular reference
4109                                         $stack[$parent] = array();
4110                                 } else {
4111                                         $nt = Title::newFromText( $parent );
4112                                         if ( $nt ) {
4113                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4114                                         }
4115                                 }
4116                         }
4117                 }
4118
4119                 return $stack;
4120         }
4121
4122         /**
4123          * Get an associative array for selecting this title from
4124          * the "page" table
4125          *
4126          * @return Array suitable for the $where parameter of DB::select()
4127          */
4128         public function pageCond() {
4129                 if ( $this->mArticleID > 0 ) {
4130                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4131                         return array( 'page_id' => $this->mArticleID );
4132                 } else {
4133                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4134                 }
4135         }
4136
4137         /**
4138          * Get the revision ID of the previous revision
4139          *
4140          * @param int $revId Revision ID. Get the revision that was before this one.
4141          * @param int $flags Title::GAID_FOR_UPDATE
4142          * @return Int|Bool Old revision ID, or FALSE if none exists
4143          */
4144         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4145                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4146                 $revId = $db->selectField( 'revision', 'rev_id',
4147                         array(
4148                                 'rev_page' => $this->getArticleID( $flags ),
4149                                 'rev_id < ' . intval( $revId )
4150                         ),
4151                         __METHOD__,
4152                         array( 'ORDER BY' => 'rev_id DESC' )
4153                 );
4154
4155                 if ( $revId === false ) {
4156                         return false;
4157                 } else {
4158                         return intval( $revId );
4159                 }
4160         }
4161
4162         /**
4163          * Get the revision ID of the next revision
4164          *
4165          * @param int $revId Revision ID. Get the revision that was after this one.
4166          * @param int $flags Title::GAID_FOR_UPDATE
4167          * @return Int|Bool Next revision ID, or FALSE if none exists
4168          */
4169         public function getNextRevisionID( $revId, $flags = 0 ) {
4170                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4171                 $revId = $db->selectField( 'revision', 'rev_id',
4172                         array(
4173                                 'rev_page' => $this->getArticleID( $flags ),
4174                                 'rev_id > ' . intval( $revId )
4175                         ),
4176                         __METHOD__,
4177                         array( 'ORDER BY' => 'rev_id' )
4178                 );
4179
4180                 if ( $revId === false ) {
4181                         return false;
4182                 } else {
4183                         return intval( $revId );
4184                 }
4185         }
4186
4187         /**
4188          * Get the first revision of the page
4189          *
4190          * @param int $flags Title::GAID_FOR_UPDATE
4191          * @return Revision|Null if page doesn't exist
4192          */
4193         public function getFirstRevision( $flags = 0 ) {
4194                 $pageId = $this->getArticleID( $flags );
4195                 if ( $pageId ) {
4196                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4197                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4198                                 array( 'rev_page' => $pageId ),
4199                                 __METHOD__,
4200                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4201                         );
4202                         if ( $row ) {
4203                                 return new Revision( $row );
4204                         }
4205                 }
4206                 return null;
4207         }
4208
4209         /**
4210          * Get the oldest revision timestamp of this page
4211          *
4212          * @param int $flags Title::GAID_FOR_UPDATE
4213          * @return String: MW timestamp
4214          */
4215         public function getEarliestRevTime( $flags = 0 ) {
4216                 $rev = $this->getFirstRevision( $flags );
4217                 return $rev ? $rev->getTimestamp() : null;
4218         }
4219
4220         /**
4221          * Check if this is a new page
4222          *
4223          * @return bool
4224          */
4225         public function isNewPage() {
4226                 $dbr = wfGetDB( DB_SLAVE );
4227                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4228         }
4229
4230         /**
4231          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4232          *
4233          * @return bool
4234          */
4235         public function isBigDeletion() {
4236                 global $wgDeleteRevisionsLimit;
4237
4238                 if ( !$wgDeleteRevisionsLimit ) {
4239                         return false;
4240                 }
4241
4242                 $revCount = $this->estimateRevisionCount();
4243                 return $revCount > $wgDeleteRevisionsLimit;
4244         }
4245
4246         /**
4247          * Get the  approximate revision count of this page.
4248          *
4249          * @return int
4250          */
4251         public function estimateRevisionCount() {
4252                 if ( !$this->exists() ) {
4253                         return 0;
4254                 }
4255
4256                 if ( $this->mEstimateRevisions === null ) {
4257                         $dbr = wfGetDB( DB_SLAVE );
4258                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4259                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4260                 }
4261
4262                 return $this->mEstimateRevisions;
4263         }
4264
4265         /**
4266          * Get the number of revisions between the given revision.
4267          * Used for diffs and other things that really need it.
4268          *
4269          * @param int|Revision $old Old revision or rev ID (first before range)
4270          * @param int|Revision $new New revision or rev ID (first after range)
4271          * @return Int Number of revisions between these revisions.
4272          */
4273         public function countRevisionsBetween( $old, $new ) {
4274                 if ( !( $old instanceof Revision ) ) {
4275                         $old = Revision::newFromTitle( $this, (int)$old );
4276                 }
4277                 if ( !( $new instanceof Revision ) ) {
4278                         $new = Revision::newFromTitle( $this, (int)$new );
4279                 }
4280                 if ( !$old || !$new ) {
4281                         return 0; // nothing to compare
4282                 }
4283                 $dbr = wfGetDB( DB_SLAVE );
4284                 return (int)$dbr->selectField( 'revision', 'count(*)',
4285                         array(
4286                                 'rev_page' => $this->getArticleID(),
4287                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4288                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4289                         ),
4290                         __METHOD__
4291                 );
4292         }
4293
4294         /**
4295          * Get the number of authors between the given revisions or revision IDs.
4296          * Used for diffs and other things that really need it.
4297          *
4298          * @param int|Revision $old Old revision or rev ID (first before range by default)
4299          * @param int|Revision $new New revision or rev ID (first after range by default)
4300          * @param int $limit Maximum number of authors
4301          * @param string|array $options (Optional): Single option, or an array of options:
4302          *     'include_old' Include $old in the range; $new is excluded.
4303          *     'include_new' Include $new in the range; $old is excluded.
4304          *     'include_both' Include both $old and $new in the range.
4305          *     Unknown option values are ignored.
4306          * @return int Number of revision authors in the range; zero if not both revisions exist
4307          */
4308         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4309                 if ( !( $old instanceof Revision ) ) {
4310                         $old = Revision::newFromTitle( $this, (int)$old );
4311                 }
4312                 if ( !( $new instanceof Revision ) ) {
4313                         $new = Revision::newFromTitle( $this, (int)$new );
4314                 }
4315                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4316                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4317                 // in the sanity check below?
4318                 if ( !$old || !$new ) {
4319                         return 0; // nothing to compare
4320                 }
4321                 $old_cmp = '>';
4322                 $new_cmp = '<';
4323                 $options = (array)$options;
4324                 if ( in_array( 'include_old', $options ) ) {
4325                         $old_cmp = '>=';
4326                 }
4327                 if ( in_array( 'include_new', $options ) ) {
4328                         $new_cmp = '<=';
4329                 }
4330                 if ( in_array( 'include_both', $options ) ) {
4331                         $old_cmp = '>=';
4332                         $new_cmp = '<=';
4333                 }
4334                 // No DB query needed if $old and $new are the same or successive revisions:
4335                 if ( $old->getId() === $new->getId() ) {
4336                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4337                 } elseif ( $old->getId() === $new->getParentId() ) {
4338                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4339                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4340                         }
4341                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4342                 }
4343                 $dbr = wfGetDB( DB_SLAVE );
4344                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4345                         array(
4346                                 'rev_page' => $this->getArticleID(),
4347                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4348                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4349                         ), __METHOD__,
4350                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4351                 );
4352                 return (int)$dbr->numRows( $res );
4353         }
4354
4355         /**
4356          * Compare with another title.
4357          *
4358          * @param $title Title
4359          * @return Bool
4360          */
4361         public function equals( Title $title ) {
4362                 // Note: === is necessary for proper matching of number-like titles.
4363                 return $this->getInterwiki() === $title->getInterwiki()
4364                         && $this->getNamespace() == $title->getNamespace()
4365                         && $this->getDBkey() === $title->getDBkey();
4366         }
4367
4368         /**
4369          * Check if this title is a subpage of another title
4370          *
4371          * @param $title Title
4372          * @return Bool
4373          */
4374         public function isSubpageOf( Title $title ) {
4375                 return $this->getInterwiki() === $title->getInterwiki()
4376                         && $this->getNamespace() == $title->getNamespace()
4377                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4378         }
4379
4380         /**
4381          * Check if page exists.  For historical reasons, this function simply
4382          * checks for the existence of the title in the page table, and will
4383          * thus return false for interwiki links, special pages and the like.
4384          * If you want to know if a title can be meaningfully viewed, you should
4385          * probably call the isKnown() method instead.
4386          *
4387          * @return Bool
4388          */
4389         public function exists() {
4390                 return $this->getArticleID() != 0;
4391         }
4392
4393         /**
4394          * Should links to this title be shown as potentially viewable (i.e. as
4395          * "bluelinks"), even if there's no record by this title in the page
4396          * table?
4397          *
4398          * This function is semi-deprecated for public use, as well as somewhat
4399          * misleadingly named.  You probably just want to call isKnown(), which
4400          * calls this function internally.
4401          *
4402          * (ISSUE: Most of these checks are cheap, but the file existence check
4403          * can potentially be quite expensive.  Including it here fixes a lot of
4404          * existing code, but we might want to add an optional parameter to skip
4405          * it and any other expensive checks.)
4406          *
4407          * @return Bool
4408          */
4409         public function isAlwaysKnown() {
4410                 $isKnown = null;
4411
4412                 /**
4413                  * Allows overriding default behavior for determining if a page exists.
4414                  * If $isKnown is kept as null, regular checks happen. If it's
4415                  * a boolean, this value is returned by the isKnown method.
4416                  *
4417                  * @since 1.20
4418                  *
4419                  * @param Title $title
4420                  * @param boolean|null $isKnown
4421                  */
4422                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4423
4424                 if ( !is_null( $isKnown ) ) {
4425                         return $isKnown;
4426                 }
4427
4428                 if ( $this->mInterwiki != '' ) {
4429                         return true;  // any interwiki link might be viewable, for all we know
4430                 }
4431
4432                 switch( $this->mNamespace ) {
4433                         case NS_MEDIA:
4434                         case NS_FILE:
4435                                 // file exists, possibly in a foreign repo
4436                                 return (bool)wfFindFile( $this );
4437                         case NS_SPECIAL:
4438                                 // valid special page
4439                                 return SpecialPageFactory::exists( $this->getDBkey() );
4440                         case NS_MAIN:
4441                                 // selflink, possibly with fragment
4442                                 return $this->mDbkeyform == '';
4443                         case NS_MEDIAWIKI:
4444                                 // known system message
4445                                 return $this->hasSourceText() !== false;
4446                         default:
4447                                 return false;
4448                 }
4449         }
4450
4451         /**
4452          * Does this title refer to a page that can (or might) be meaningfully
4453          * viewed?  In particular, this function may be used to determine if
4454          * links to the title should be rendered as "bluelinks" (as opposed to
4455          * "redlinks" to non-existent pages).
4456          * Adding something else to this function will cause inconsistency
4457          * since LinkHolderArray calls isAlwaysKnown() and does its own
4458          * page existence check.
4459          *
4460          * @return Bool
4461          */
4462         public function isKnown() {
4463                 return $this->isAlwaysKnown() || $this->exists();
4464         }
4465
4466         /**
4467          * Does this page have source text?
4468          *
4469          * @return Boolean
4470          */
4471         public function hasSourceText() {
4472                 if ( $this->exists() ) {
4473                         return true;
4474                 }
4475
4476                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4477                         // If the page doesn't exist but is a known system message, default
4478                         // message content will be displayed, same for language subpages-
4479                         // Use always content language to avoid loading hundreds of languages
4480                         // to get the link color.
4481                         global $wgContLang;
4482                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4483                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4484                         return $message->exists();
4485                 }
4486
4487                 return false;
4488         }
4489
4490         /**
4491          * Get the default message text or false if the message doesn't exist
4492          *
4493          * @return String or false
4494          */
4495         public function getDefaultMessageText() {
4496                 global $wgContLang;
4497
4498                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4499                         return false;
4500                 }
4501
4502                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4503                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4504
4505                 if ( $message->exists() ) {
4506                         return $message->plain();
4507                 } else {
4508                         return false;
4509                 }
4510         }
4511
4512         /**
4513          * Updates page_touched for this page; called from LinksUpdate.php
4514          *
4515          * @return Bool true if the update succeeded
4516          */
4517         public function invalidateCache() {
4518                 global $wgMemc;
4519
4520                 if ( wfReadOnly() ) {
4521                         return false;
4522                 }
4523
4524                 $dbw = wfGetDB( DB_MASTER );
4525                 $conds = $this->pageCond();
4526                 $dbw->onTransactionIdle( function() use ( $dbw, $conds ) {
4527                         $dbw->update(
4528                                 'page',
4529                                 array( 'page_touched' => $dbw->timestamp() ),
4530                                 $conds,
4531                                 __METHOD__
4532                         );
4533                 } );
4534                 HTMLFileCache::clearFileCache( $this );
4535
4536                 // Clear page info.
4537                 $revision = WikiPage::factory( $this )->getRevision();
4538                 if ( $revision !== null ) {
4539                         $memcKey = wfMemcKey( 'infoaction', $this->getPrefixedText(), $revision->getId() );
4540                         $success = $wgMemc->delete( $memcKey );
4541                 } else {
4542                         $success = true;
4543                 }
4544
4545                 return $success;
4546         }
4547
4548         /**
4549          * Update page_touched timestamps and send squid purge messages for
4550          * pages linking to this title. May be sent to the job queue depending
4551          * on the number of links. Typically called on create and delete.
4552          */
4553         public function touchLinks() {
4554                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4555                 $u->doUpdate();
4556
4557                 if ( $this->getNamespace() == NS_CATEGORY ) {
4558                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4559                         $u->doUpdate();
4560                 }
4561         }
4562
4563         /**
4564          * Get the last touched timestamp
4565          *
4566          * @param $db DatabaseBase: optional db
4567          * @return String last-touched timestamp
4568          */
4569         public function getTouched( $db = null ) {
4570                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4571                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4572                 return $touched;
4573         }
4574
4575         /**
4576          * Get the timestamp when this page was updated since the user last saw it.
4577          *
4578          * @param $user User
4579          * @return String|Null
4580          */
4581         public function getNotificationTimestamp( $user = null ) {
4582                 global $wgUser, $wgShowUpdatedMarker;
4583                 // Assume current user if none given
4584                 if ( !$user ) {
4585                         $user = $wgUser;
4586                 }
4587                 // Check cache first
4588                 $uid = $user->getId();
4589                 // avoid isset here, as it'll return false for null entries
4590                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4591                         return $this->mNotificationTimestamp[$uid];
4592                 }
4593                 if ( !$uid || !$wgShowUpdatedMarker ) {
4594                         return $this->mNotificationTimestamp[$uid] = false;
4595                 }
4596                 // Don't cache too much!
4597                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4598                         $this->mNotificationTimestamp = array();
4599                 }
4600                 $dbr = wfGetDB( DB_SLAVE );
4601                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4602                         'wl_notificationtimestamp',
4603                         array(
4604                                 'wl_user' => $user->getId(),
4605                                 'wl_namespace' => $this->getNamespace(),
4606                                 'wl_title' => $this->getDBkey(),
4607                         ),
4608                         __METHOD__
4609                 );
4610                 return $this->mNotificationTimestamp[$uid];
4611         }
4612
4613         /**
4614          * Generate strings used for xml 'id' names in monobook tabs
4615          *
4616          * @param string $prepend defaults to 'nstab-'
4617          * @return String XML 'id' name
4618          */
4619         public function getNamespaceKey( $prepend = 'nstab-' ) {
4620                 global $wgContLang;
4621                 // Gets the subject namespace if this title
4622                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4623                 // Checks if canonical namespace name exists for namespace
4624                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4625                         // Uses canonical namespace name
4626                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4627                 } else {
4628                         // Uses text of namespace
4629                         $namespaceKey = $this->getSubjectNsText();
4630                 }
4631                 // Makes namespace key lowercase
4632                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4633                 // Uses main
4634                 if ( $namespaceKey == '' ) {
4635                         $namespaceKey = 'main';
4636                 }
4637                 // Changes file to image for backwards compatibility
4638                 if ( $namespaceKey == 'file' ) {
4639                         $namespaceKey = 'image';
4640                 }
4641                 return $prepend . $namespaceKey;
4642         }
4643
4644         /**
4645          * Get all extant redirects to this Title
4646          *
4647          * @param int|Null $ns Single namespace to consider; NULL to consider all namespaces
4648          * @return Array of Title redirects to this title
4649          */
4650         public function getRedirectsHere( $ns = null ) {
4651                 $redirs = array();
4652
4653                 $dbr = wfGetDB( DB_SLAVE );
4654                 $where = array(
4655                         'rd_namespace' => $this->getNamespace(),
4656                         'rd_title' => $this->getDBkey(),
4657                         'rd_from = page_id'
4658                 );
4659                 if ( $this->isExternal() ) {
4660                         $where['rd_interwiki'] = $this->getInterwiki();
4661                 } else {
4662                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4663                 }
4664                 if ( !is_null( $ns ) ) {
4665                         $where['page_namespace'] = $ns;
4666                 }
4667
4668                 $res = $dbr->select(
4669                         array( 'redirect', 'page' ),
4670                         array( 'page_namespace', 'page_title' ),
4671                         $where,
4672                         __METHOD__
4673                 );
4674
4675                 foreach ( $res as $row ) {
4676                         $redirs[] = self::newFromRow( $row );
4677                 }
4678                 return $redirs;
4679         }
4680
4681         /**
4682          * Check if this Title is a valid redirect target
4683          *
4684          * @return Bool
4685          */
4686         public function isValidRedirectTarget() {
4687                 global $wgInvalidRedirectTargets;
4688
4689                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4690                 if ( $this->isSpecial( 'Userlogout' ) ) {
4691                         return false;
4692                 }
4693
4694                 foreach ( $wgInvalidRedirectTargets as $target ) {
4695                         if ( $this->isSpecial( $target ) ) {
4696                                 return false;
4697                         }
4698                 }
4699
4700                 return true;
4701         }
4702
4703         /**
4704          * Get a backlink cache object
4705          *
4706          * @return BacklinkCache
4707          */
4708         public function getBacklinkCache() {
4709                 return BacklinkCache::get( $this );
4710         }
4711
4712         /**
4713          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4714          *
4715          * @return Boolean
4716          */
4717         public function canUseNoindex() {
4718                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4719
4720                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4721                         ? $wgContentNamespaces
4722                         : $wgExemptFromUserRobotsControl;
4723
4724                 return !in_array( $this->mNamespace, $bannedNamespaces );
4725
4726         }
4727
4728         /**
4729          * Returns the raw sort key to be used for categories, with the specified
4730          * prefix.  This will be fed to Collation::getSortKey() to get a
4731          * binary sortkey that can be used for actual sorting.
4732          *
4733          * @param string $prefix The prefix to be used, specified using
4734          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4735          *   prefix.
4736          * @return string
4737          */
4738         public function getCategorySortkey( $prefix = '' ) {
4739                 $unprefixed = $this->getText();
4740
4741                 // Anything that uses this hook should only depend
4742                 // on the Title object passed in, and should probably
4743                 // tell the users to run updateCollations.php --force
4744                 // in order to re-sort existing category relations.
4745                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4746                 if ( $prefix !== '' ) {
4747                         # Separate with a line feed, so the unprefixed part is only used as
4748                         # a tiebreaker when two pages have the exact same prefix.
4749                         # In UCA, tab is the only character that can sort above LF
4750                         # so we strip both of them from the original prefix.
4751                         $prefix = strtr( $prefix, "\n\t", '  ' );
4752                         return "$prefix\n$unprefixed";
4753                 }
4754                 return $unprefixed;
4755         }
4756
4757         /**
4758          * Get the language in which the content of this page is written in
4759          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4760          * e.g. $wgLang (such as special pages, which are in the user language).
4761          *
4762          * @since 1.18
4763          * @return Language
4764          */
4765         public function getPageLanguage() {
4766                 global $wgLang;
4767                 if ( $this->isSpecialPage() ) {
4768                         // special pages are in the user language
4769                         return $wgLang;
4770                 }
4771
4772                 //TODO: use the LinkCache to cache this! Note that this may depend on user settings, so the cache should be only per-request.
4773                 //NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4774                 $contentHandler = ContentHandler::getForTitle( $this );
4775                 $pageLang = $contentHandler->getPageLanguage( $this );
4776
4777                 return wfGetLangObj( $pageLang );
4778         }
4779
4780         /**
4781          * Get the language in which the content of this page is written when
4782          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4783          * e.g. $wgLang (such as special pages, which are in the user language).
4784          *
4785          * @since 1.20
4786          * @return Language
4787          */
4788         public function getPageViewLanguage() {
4789                 global $wgLang;
4790
4791                 if ( $this->isSpecialPage() ) {
4792                         // If the user chooses a variant, the content is actually
4793                         // in a language whose code is the variant code.
4794                         $variant = $wgLang->getPreferredVariant();
4795                         if ( $wgLang->getCode() !== $variant ) {
4796                                 return Language::factory( $variant );
4797                         }
4798
4799                         return $wgLang;
4800                 }
4801
4802                 //NOTE: can't be cached persistently, depends on user settings
4803                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4804                 $contentHandler = ContentHandler::getForTitle( $this );
4805                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4806                 return $pageLang;
4807         }
4808
4809         /**
4810          * Get a list of rendered edit notices for this page.
4811          *
4812          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4813          * they will already be wrapped in paragraphs.
4814          *
4815          * @since 1.21
4816          * @return Array
4817          */
4818         public function getEditNotices() {
4819                 $notices = array();
4820
4821                 # Optional notices on a per-namespace and per-page basis
4822                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4823                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4824                 if ( $editnotice_ns_message->exists() ) {
4825                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4826                 }
4827                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4828                         $parts = explode( '/', $this->getDBkey() );
4829                         $editnotice_base = $editnotice_ns;
4830                         while ( count( $parts ) > 0 ) {
4831                                 $editnotice_base .= '-' . array_shift( $parts );
4832                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4833                                 if ( $editnotice_base_msg->exists() ) {
4834                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4835                                 }
4836                         }
4837                 } else {
4838                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4839                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4840                         $editnoticeMsg = wfMessage( $editnoticeText );
4841                         if ( $editnoticeMsg->exists() ) {
4842                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4843                         }
4844                 }
4845                 return $notices;
4846         }
4847 }