includes/Title.php

   1 <?php
   2 /**
   3  * Representation of 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  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  *
  33  * @internal documentation reviewed 15 Mar 2010
  34  */
  35 class Title {
  36         /** @var MapCacheLRU */
  37         static private $titleCache = null;
  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
  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 = null;        ///< 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         # Zero except in {{transclusion}} tags
  83         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  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         private $mPageLanguage = false;   // /< The (string) language code of the page's language and content code.
  90         private $mTitleValue = null;      // /< A corresponding TitleValue object
  91         // @}
  92
  93         /**
  94          * B/C kludge: provide a TitleParser for use by Title.
  95          * Ideally, Title would have no methods that need this.
  96          * Avoid usage of this singleton by using TitleValue
  97          * and the associated services when possible.
  98          *
  99          * @return TitleParser
 100          */
 101         private static function getTitleParser() {
 102                 global $wgContLang, $wgLocalInterwikis;
 103
 104                 static $titleCodec = null;
 105                 static $titleCodecFingerprint = null;
 106
 107                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 108                 // make sure we are using the right one. To detect changes over the course
 109                 // of a request, we remember a fingerprint of the config used to create the
 110                 // codec singleton, and re-create it if the fingerprint doesn't match.
 111                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 112
 113                 if ( $fingerprint !== $titleCodecFingerprint ) {
 114                         $titleCodec = null;
 115                 }
 116
 117                 if ( !$titleCodec ) {
 118                         $titleCodec = new MediaWikiTitleCodec( $wgContLang, GenderCache::singleton(), $wgLocalInterwikis );
 119                         $titleCodecFingerprint = $fingerprint;
 120                 }
 121
 122                 return $titleCodec;
 123         }
 124
 125         /**
 126          * B/C kludge: provide a TitleParser for use by Title.
 127          * Ideally, Title would have no methods that need this.
 128          * Avoid usage of this singleton by using TitleValue
 129          * and the associated services when possible.
 130          *
 131          * @return TitleFormatter
 132          */
 133         private static function getTitleFormatter() {
 134                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 135                 //      which implements TitleFormatter.
 136                 return self::getTitleParser();
 137         }
 138
 139         /**
 140          * Constructor
 141          */
 142         /*protected*/ function __construct() { }
 143
 144         /**
 145          * Create a new Title from a prefixed DB key
 146          *
 147          * @param string $key The database key, which has underscores
 148          *      instead of spaces, possibly including namespace and
 149          *      interwiki prefixes
 150          * @return Title|null Title, or null on an error
 151          */
 152         public static function newFromDBkey( $key ) {
 153                 $t = new Title();
 154                 $t->mDbkeyform = $key;
 155                 if ( $t->secureAndSplit() ) {
 156                         return $t;
 157                 } else {
 158                         return null;
 159                 }
 160         }
 161
 162         /**
 163          * Create a new Title from a TitleValue
 164          *
 165          * @param TitleValue $titleValue Assumed to be safe.
 166          *
 167          * @return Title
 168          */
 169         public static function newFromTitleValue( TitleValue $titleValue ) {
 170                 return self::makeTitle(
 171                         $titleValue->getNamespace(),
 172                         $titleValue->getText(),
 173                         $titleValue->getFragment() );
 174         }
 175
 176         /**
 177          * Create a new Title from text, such as what one would find in a link. De-
 178          * codes any HTML entities in the text.
 179          *
 180          * @param string $text The link text; spaces, prefixes, and an
 181          *   initial ':' indicating the main namespace are accepted.
 182          * @param int $defaultNamespace The namespace to use if none is specified
 183          *   by a prefix.  If you want to force a specific namespace even if
 184          *   $text might begin with a namespace prefix, use makeTitle() or
 185          *   makeTitleSafe().
 186          * @throws MWException
 187          * @return Title|null Title or null on an error.
 188          */
 189         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 190                 if ( is_object( $text ) ) {
 191                         throw new MWException( 'Title::newFromText given an object' );
 192                 }
 193
 194                 $cache = self::getTitleCache();
 195
 196                 /**
 197                  * Wiki pages often contain multiple links to the same page.
 198                  * Title normalization and parsing can become expensive on
 199                  * pages with many links, so we can save a little time by
 200                  * caching them.
 201                  *
 202                  * In theory these are value objects and won't get changed...
 203                  */
 204                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 205                         return $cache->get( $text );
 206                 }
 207
 208                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 209                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 210
 211                 $t = new Title();
 212                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 213                 $t->mDefaultNamespace = intval( $defaultNamespace );
 214
 215                 if ( $t->secureAndSplit() ) {
 216                         if ( $defaultNamespace == NS_MAIN ) {
 217                                 $cache->set( $text, $t );
 218                         }
 219                         return $t;
 220                 } else {
 221                         $ret = null;
 222                         return $ret;
 223                 }
 224         }
 225
 226         /**
 227          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 228          *
 229          * Example of wrong and broken code:
 230          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 231          *
 232          * Example of right code:
 233          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 234          *
 235          * Create a new Title from URL-encoded text. Ensures that
 236          * the given title's length does not exceed the maximum.
 237          *
 238          * @param string $url The title, as might be taken from a URL
 239          * @return Title|null The new object, or null on an error
 240          */
 241         public static function newFromURL( $url ) {
 242                 $t = new Title();
 243
 244                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 245                 # but some URLs used it as a space replacement and they still come
 246                 # from some external search tools.
 247                 if ( strpos( self::legalChars(), '+' ) === false ) {
 248                         $url = str_replace( '+', ' ', $url );
 249                 }
 250
 251                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 252                 if ( $t->secureAndSplit() ) {
 253                         return $t;
 254                 } else {
 255                         return null;
 256                 }
 257         }
 258
 259         /**
 260          * @return MapCacheLRU
 261          */
 262         private static function getTitleCache() {
 263                 if ( self::$titleCache == null ) {
 264                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 265                 }
 266                 return self::$titleCache;
 267         }
 268
 269         /**
 270          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 271          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 272          *
 273          * @return array
 274          */
 275         protected static function getSelectFields() {
 276                 global $wgContentHandlerUseDB;
 277
 278                 $fields = array(
 279                         'page_namespace', 'page_title', 'page_id',
 280                         'page_len', 'page_is_redirect', 'page_latest',
 281                 );
 282
 283                 if ( $wgContentHandlerUseDB ) {
 284                         $fields[] = 'page_content_model';
 285                 }
 286
 287                 return $fields;
 288         }
 289
 290         /**
 291          * Create a new Title from an article ID
 292          *
 293          * @param int $id The page_id corresponding to the Title to create
 294          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 295          * @return Title|null The new object, or null on an error
 296          */
 297         public static function newFromID( $id, $flags = 0 ) {
 298                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 299                 $row = $db->selectRow(
 300                         'page',
 301                         self::getSelectFields(),
 302                         array( 'page_id' => $id ),
 303                         __METHOD__
 304                 );
 305                 if ( $row !== false ) {
 306                         $title = Title::newFromRow( $row );
 307                 } else {
 308                         $title = null;
 309                 }
 310                 return $title;
 311         }
 312
 313         /**
 314          * Make an array of titles from an array of IDs
 315          *
 316          * @param int[] $ids Array of IDs
 317          * @return Title[] Array of Titles
 318          */
 319         public static function newFromIDs( $ids ) {
 320                 if ( !count( $ids ) ) {
 321                         return array();
 322                 }
 323                 $dbr = wfGetDB( DB_SLAVE );
 324
 325                 $res = $dbr->select(
 326                         'page',
 327                         self::getSelectFields(),
 328                         array( 'page_id' => $ids ),
 329                         __METHOD__
 330                 );
 331
 332                 $titles = array();
 333                 foreach ( $res as $row ) {
 334                         $titles[] = Title::newFromRow( $row );
 335                 }
 336                 return $titles;
 337         }
 338
 339         /**
 340          * Make a Title object from a DB row
 341          *
 342          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 343          * @return Title Corresponding Title
 344          */
 345         public static function newFromRow( $row ) {
 346                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 347                 $t->loadFromRow( $row );
 348                 return $t;
 349         }
 350
 351         /**
 352          * Load Title object fields from a DB row.
 353          * If false is given, the title will be treated as non-existing.
 354          *
 355          * @param stdClass|bool $row Database row
 356          */
 357         public function loadFromRow( $row ) {
 358                 if ( $row ) { // page found
 359                         if ( isset( $row->page_id ) ) {
 360                                 $this->mArticleID = (int)$row->page_id;
 361                         }
 362                         if ( isset( $row->page_len ) ) {
 363                                 $this->mLength = (int)$row->page_len;
 364                         }
 365                         if ( isset( $row->page_is_redirect ) ) {
 366                                 $this->mRedirect = (bool)$row->page_is_redirect;
 367                         }
 368                         if ( isset( $row->page_latest ) ) {
 369                                 $this->mLatestID = (int)$row->page_latest;
 370                         }
 371                         if ( isset( $row->page_content_model ) ) {
 372                                 $this->mContentModel = strval( $row->page_content_model );
 373                         } else {
 374                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 375                         }
 376                 } else { // page not found
 377                         $this->mArticleID = 0;
 378                         $this->mLength = 0;
 379                         $this->mRedirect = false;
 380                         $this->mLatestID = 0;
 381                         $this->mContentModel = false; # initialized lazily in getContentModel()
 382                 }
 383         }
 384
 385         /**
 386          * Create a new Title from a namespace index and a DB key.
 387          * It's assumed that $ns and $title are *valid*, for instance when
 388          * they came directly from the database or a special page name.
 389          * For convenience, spaces are converted to underscores so that
 390          * eg user_text fields can be used directly.
 391          *
 392          * @param int $ns The namespace of the article
 393          * @param string $title The unprefixed database key form
 394          * @param string $fragment The link fragment (after the "#")
 395          * @param string $interwiki The interwiki prefix
 396          * @return Title The new object
 397          */
 398         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 399                 $t = new Title();
 400                 $t->mInterwiki = $interwiki;
 401                 $t->mFragment = $fragment;
 402                 $t->mNamespace = $ns = intval( $ns );
 403                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 404                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 405                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 406                 $t->mTextform = str_replace( '_', ' ', $title );
 407                 $t->mContentModel = false; # initialized lazily in getContentModel()
 408                 return $t;
 409         }
 410
 411         /**
 412          * Create a new Title from a namespace index and a DB key.
 413          * The parameters will be checked for validity, which is a bit slower
 414          * than makeTitle() but safer for user-provided data.
 415          *
 416          * @param int $ns The namespace of the article
 417          * @param string $title Database key form
 418          * @param string $fragment The link fragment (after the "#")
 419          * @param string $interwiki Interwiki prefix
 420          * @return Title The new object, or null on an error
 421          */
 422         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 423                 if ( !MWNamespace::exists( $ns ) ) {
 424                         return null;
 425                 }
 426
 427                 $t = new Title();
 428                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 429                 if ( $t->secureAndSplit() ) {
 430                         return $t;
 431                 } else {
 432                         return null;
 433                 }
 434         }
 435
 436         /**
 437          * Create a new Title for the Main Page
 438          *
 439          * @return Title The new object
 440          */
 441         public static function newMainPage() {
 442                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 443                 // Don't give fatal errors if the message is broken
 444                 if ( !$title ) {
 445                         $title = Title::newFromText( 'Main Page' );
 446                 }
 447                 return $title;
 448         }
 449
 450         /**
 451          * Extract a redirect destination from a string and return the
 452          * Title, or null if the text doesn't contain a valid redirect
 453          * This will only return the very next target, useful for
 454          * the redirect table and other checks that don't need full recursion
 455          *
 456          * @param string $text Text with possible redirect
 457          * @return Title The corresponding Title
 458          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 459          */
 460         public static function newFromRedirect( $text ) {
 461                 ContentHandler::deprecated( __METHOD__, '1.21' );
 462
 463                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 464                 return $content->getRedirectTarget();
 465         }
 466
 467         /**
 468          * Extract a redirect destination from a string and return the
 469          * Title, or null if the text doesn't contain a valid redirect
 470          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 471          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 472          *
 473          * @param string $text Text with possible redirect
 474          * @return Title
 475          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 476          */
 477         public static function newFromRedirectRecurse( $text ) {
 478                 ContentHandler::deprecated( __METHOD__, '1.21' );
 479
 480                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 481                 return $content->getUltimateRedirectTarget();
 482         }
 483
 484         /**
 485          * Extract a redirect destination from a string and return an
 486          * array of Titles, or null if the text doesn't contain a valid redirect
 487          * The last element in the array is the final destination after all redirects
 488          * have been resolved (up to $wgMaxRedirects times)
 489          *
 490          * @param string $text Text with possible redirect
 491          * @return Title[] Array of Titles, with the destination last
 492          * @deprecated since 1.21, use Content::getRedirectChain instead.
 493          */
 494         public static function newFromRedirectArray( $text ) {
 495                 ContentHandler::deprecated( __METHOD__, '1.21' );
 496
 497                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 498                 return $content->getRedirectChain();
 499         }
 500
 501         /**
 502          * Get the prefixed DB key associated with an ID
 503          *
 504          * @param int $id The page_id of the article
 505          * @return Title|null An object representing the article, or null if no such article was found
 506          */
 507         public static function nameOf( $id ) {
 508                 $dbr = wfGetDB( DB_SLAVE );
 509
 510                 $s = $dbr->selectRow(
 511                         'page',
 512                         array( 'page_namespace', 'page_title' ),
 513                         array( 'page_id' => $id ),
 514                         __METHOD__
 515                 );
 516                 if ( $s === false ) {
 517                         return null;
 518                 }
 519
 520                 $n = self::makeName( $s->page_namespace, $s->page_title );
 521                 return $n;
 522         }
 523
 524         /**
 525          * Get a regex character class describing the legal characters in a link
 526          *
 527          * @return string The list of characters, not delimited
 528          */
 529         public static function legalChars() {
 530                 global $wgLegalTitleChars;
 531                 return $wgLegalTitleChars;
 532         }
 533
 534         /**
 535          * Returns a simple regex that will match on characters and sequences invalid in titles.
 536          * Note that this doesn't pick up many things that could be wrong with titles, but that
 537          * replacing this regex with something valid will make many titles valid.
 538          *
 539          * @todo: move this into MediaWikiTitleCodec
 540          *
 541          * @return string Regex string
 542          */
 543         static function getTitleInvalidRegex() {
 544                 static $rxTc = false;
 545                 if ( !$rxTc ) {
 546                         # Matching titles will be held as illegal.
 547                         $rxTc = '/' .
 548                                 # Any character not allowed is forbidden...
 549                                 '[^' . self::legalChars() . ']' .
 550                                 # URL percent encoding sequences interfere with the ability
 551                                 # to round-trip titles -- you can't link to them consistently.
 552                                 '|%[0-9A-Fa-f]{2}' .
 553                                 # XML/HTML character references produce similar issues.
 554                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 555                                 '|&#[0-9]+;' .
 556                                 '|&#x[0-9A-Fa-f]+;' .
 557                                 '/S';
 558                 }
 559
 560                 return $rxTc;
 561         }
 562
 563         /**
 564          * Utility method for converting a character sequence from bytes to Unicode.
 565          *
 566          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 567          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 568          *
 569          * @param string $byteClass
 570          * @return string
 571          */
 572         public static function convertByteClassToUnicodeClass( $byteClass ) {
 573                 $length = strlen( $byteClass );
 574                 // Input token queue
 575                 $x0 = $x1 = $x2 = '';
 576                 // Decoded queue
 577                 $d0 = $d1 = $d2 = '';
 578                 // Decoded integer codepoints
 579                 $ord0 = $ord1 = $ord2 = 0;
 580                 // Re-encoded queue
 581                 $r0 = $r1 = $r2 = '';
 582                 // Output
 583                 $out = '';
 584                 // Flags
 585                 $allowUnicode = false;
 586                 for ( $pos = 0; $pos < $length; $pos++ ) {
 587                         // Shift the queues down
 588                         $x2 = $x1;
 589                         $x1 = $x0;
 590                         $d2 = $d1;
 591                         $d1 = $d0;
 592                         $ord2 = $ord1;
 593                         $ord1 = $ord0;
 594                         $r2 = $r1;
 595                         $r1 = $r0;
 596                         // Load the current input token and decoded values
 597                         $inChar = $byteClass[$pos];
 598                         if ( $inChar == '\\' ) {
 599                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 600                                         $x0 = $inChar . $m[0];
 601                                         $d0 = chr( hexdec( $m[1] ) );
 602                                         $pos += strlen( $m[0] );
 603                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 604                                         $x0 = $inChar . $m[0];
 605                                         $d0 = chr( octdec( $m[0] ) );
 606                                         $pos += strlen( $m[0] );
 607                                 } elseif ( $pos + 1 >= $length ) {
 608                                         $x0 = $d0 = '\\';
 609                                 } else {
 610                                         $d0 = $byteClass[$pos + 1];
 611                                         $x0 = $inChar . $d0;
 612                                         $pos += 1;
 613                                 }
 614                         } else {
 615                                 $x0 = $d0 = $inChar;
 616                         }
 617                         $ord0 = ord( $d0 );
 618                         // Load the current re-encoded value
 619                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 620                                 $r0 = sprintf( '\x%02x', $ord0 );
 621                         } elseif ( $ord0 >= 0x80 ) {
 622                                 // Allow unicode if a single high-bit character appears
 623                                 $r0 = sprintf( '\x%02x', $ord0 );
 624                                 $allowUnicode = true;
 625                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 626                                 $r0 = '\\' . $d0;
 627                         } else {
 628                                 $r0 = $d0;
 629                         }
 630                         // Do the output
 631                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 632                                 // Range
 633                                 if ( $ord2 > $ord0 ) {
 634                                         // Empty range
 635                                 } elseif ( $ord0 >= 0x80 ) {
 636                                         // Unicode range
 637                                         $allowUnicode = true;
 638                                         if ( $ord2 < 0x80 ) {
 639                                                 // Keep the non-unicode section of the range
 640                                                 $out .= "$r2-\\x7F";
 641                                         }
 642                                 } else {
 643                                         // Normal range
 644                                         $out .= "$r2-$r0";
 645                                 }
 646                                 // Reset state to the initial value
 647                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 648                         } elseif ( $ord2 < 0x80 ) {
 649                                 // ASCII character
 650                                 $out .= $r2;
 651                         }
 652                 }
 653                 if ( $ord1 < 0x80 ) {
 654                         $out .= $r1;
 655                 }
 656                 if ( $ord0 < 0x80 ) {
 657                         $out .= $r0;
 658                 }
 659                 if ( $allowUnicode ) {
 660                         $out .= '\u0080-\uFFFF';
 661                 }
 662                 return $out;
 663         }
 664
 665         /**
 666          * Make a prefixed DB key from a DB key and a namespace index
 667          *
 668          * @param int $ns Numerical representation of the namespace
 669          * @param string $title The DB key form the title
 670          * @param string $fragment The link fragment (after the "#")
 671          * @param string $interwiki The interwiki prefix
 672          * @return string The prefixed form of the title
 673          */
 674         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 675                 global $wgContLang;
 676
 677                 $namespace = $wgContLang->getNsText( $ns );
 678                 $name = $namespace == '' ? $title : "$namespace:$title";
 679                 if ( strval( $interwiki ) != '' ) {
 680                         $name = "$interwiki:$name";
 681                 }
 682                 if ( strval( $fragment ) != '' ) {
 683                         $name .= '#' . $fragment;
 684                 }
 685                 return $name;
 686         }
 687
 688         /**
 689          * Escape a text fragment, say from a link, for a URL
 690          *
 691          * @param string $fragment Containing a URL or link fragment (after the "#")
 692          * @return string Escaped string
 693          */
 694         static function escapeFragmentForURL( $fragment ) {
 695                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 696                 # fragments appear not to work in IE (at least up to 7) or in at least
 697                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 698                 # to care if they aren't encoded.
 699                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 700         }
 701
 702         /**
 703          * Callback for usort() to do title sorts by (namespace, title)
 704          *
 705          * @param Title $a
 706          * @param Title $b
 707          *
 708          * @return int Result of string comparison, or namespace comparison
 709          */
 710         public static function compare( $a, $b ) {
 711                 if ( $a->getNamespace() == $b->getNamespace() ) {
 712                         return strcmp( $a->getText(), $b->getText() );
 713                 } else {
 714                         return $a->getNamespace() - $b->getNamespace();
 715                 }
 716         }
 717
 718         /**
 719          * Determine whether the object refers to a page within
 720          * this project.
 721          *
 722          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 723          */
 724         public function isLocal() {
 725                 if ( $this->isExternal() ) {
 726                         $iw = Interwiki::fetch( $this->mInterwiki );
 727                         if ( $iw ) {
 728                                 return $iw->isLocal();
 729                         }
 730                 }
 731                 return true;
 732         }
 733
 734         /**
 735          * Is this Title interwiki?
 736          *
 737          * @return bool
 738          */
 739         public function isExternal() {
 740                 return $this->mInterwiki !== '';
 741         }
 742
 743         /**
 744          * Get the interwiki prefix
 745          *
 746          * Use Title::isExternal to check if a interwiki is set
 747          *
 748          * @return string Interwiki prefix
 749          */
 750         public function getInterwiki() {
 751                 return $this->mInterwiki;
 752         }
 753
 754         /**
 755          * Determine whether the object refers to a page within
 756          * this project and is transcludable.
 757          *
 758          * @return bool True if this is transcludable
 759          */
 760         public function isTrans() {
 761                 if ( !$this->isExternal() ) {
 762                         return false;
 763                 }
 764
 765                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 766         }
 767
 768         /**
 769          * Returns the DB name of the distant wiki which owns the object.
 770          *
 771          * @return string The DB name
 772          */
 773         public function getTransWikiID() {
 774                 if ( !$this->isExternal() ) {
 775                         return false;
 776                 }
 777
 778                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 779         }
 780
 781         /**
 782          * Get a TitleValue object representing this Title.
 783          *
 784          * @note: Not all valid Titles have a corresponding valid TitleValue
 785          * (e.g. TitleValues cannot represent page-local links that have a
 786          * fragment but no title text).
 787          *
 788          * @return TitleValue|null
 789          */
 790         public function getTitleValue() {
 791                 if ( $this->mTitleValue === null ) {
 792                         try {
 793                                 $this->mTitleValue = new TitleValue(
 794                                         $this->getNamespace(),
 795                                         $this->getDBkey(),
 796                                         $this->getFragment() );
 797                         } catch ( InvalidArgumentException $ex ) {
 798                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 799                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 800                         }
 801                 }
 802
 803                 return $this->mTitleValue;
 804         }
 805
 806         /**
 807          * Get the text form (spaces not underscores) of the main part
 808          *
 809          * @return string Main part of the title
 810          */
 811         public function getText() {
 812                 return $this->mTextform;
 813         }
 814
 815         /**
 816          * Get the URL-encoded form of the main part
 817          *
 818          * @return string Main part of the title, URL-encoded
 819          */
 820         public function getPartialURL() {
 821                 return $this->mUrlform;
 822         }
 823
 824         /**
 825          * Get the main part with underscores
 826          *
 827          * @return string Main part of the title, with underscores
 828          */
 829         public function getDBkey() {
 830                 return $this->mDbkeyform;
 831         }
 832
 833         /**
 834          * Get the DB key with the initial letter case as specified by the user
 835          *
 836          * @return string DB key
 837          */
 838         function getUserCaseDBKey() {
 839                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 840                         return $this->mUserCaseDBKey;
 841                 } else {
 842                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 843                         return $this->mDbkeyform;
 844                 }
 845         }
 846
 847         /**
 848          * Get the namespace index, i.e. one of the NS_xxxx constants.
 849          *
 850          * @return int Namespace index
 851          */
 852         public function getNamespace() {
 853                 return $this->mNamespace;
 854         }
 855
 856         /**
 857          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 858          *
 859          * @throws MWException
 860          * @return string Content model id
 861          */
 862         public function getContentModel() {
 863                 if ( !$this->mContentModel ) {
 864                         $linkCache = LinkCache::singleton();
 865                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 866                 }
 867
 868                 if ( !$this->mContentModel ) {
 869                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 870                 }
 871
 872                 if ( !$this->mContentModel ) {
 873                         throw new MWException( 'Failed to determine content model!' );
 874                 }
 875
 876                 return $this->mContentModel;
 877         }
 878
 879         /**
 880          * Convenience method for checking a title's content model name
 881          *
 882          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 883          * @return bool True if $this->getContentModel() == $id
 884          */
 885         public function hasContentModel( $id ) {
 886                 return $this->getContentModel() == $id;
 887         }
 888
 889         /**
 890          * Get the namespace text
 891          *
 892          * @return string Namespace text
 893          */
 894         public function getNsText() {
 895                 if ( $this->isExternal() ) {
 896                         // This probably shouldn't even happen. ohh man, oh yuck.
 897                         // But for interwiki transclusion it sometimes does.
 898                         // Shit. Shit shit shit.
 899                         //
 900                         // Use the canonical namespaces if possible to try to
 901                         // resolve a foreign namespace.
 902                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 903                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 904                         }
 905                 }
 906
 907                 try {
 908                         $formatter = $this->getTitleFormatter();
 909                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 910                 } catch ( InvalidArgumentException $ex )  {
 911                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 912                         return false;
 913                 }
 914         }
 915
 916         /**
 917          * Get the namespace text of the subject (rather than talk) page
 918          *
 919          * @return string Namespace text
 920          */
 921         public function getSubjectNsText() {
 922                 global $wgContLang;
 923                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 924         }
 925
 926         /**
 927          * Get the namespace text of the talk page
 928          *
 929          * @return string Namespace text
 930          */
 931         public function getTalkNsText() {
 932                 global $wgContLang;
 933                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 934         }
 935
 936         /**
 937          * Could this title have a corresponding talk page?
 938          *
 939          * @return bool
 940          */
 941         public function canTalk() {
 942                 return MWNamespace::canTalk( $this->mNamespace );
 943         }
 944
 945         /**
 946          * Is this in a namespace that allows actual pages?
 947          *
 948          * @return bool
 949          * @internal note -- uses hardcoded namespace index instead of constants
 950          */
 951         public function canExist() {
 952                 return $this->mNamespace >= NS_MAIN;
 953         }
 954
 955         /**
 956          * Can this title be added to a user's watchlist?
 957          *
 958          * @return bool
 959          */
 960         public function isWatchable() {
 961                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 962         }
 963
 964         /**
 965          * Returns true if this is a special page.
 966          *
 967          * @return bool
 968          */
 969         public function isSpecialPage() {
 970                 return $this->getNamespace() == NS_SPECIAL;
 971         }
 972
 973         /**
 974          * Returns true if this title resolves to the named special page
 975          *
 976          * @param string $name The special page name
 977          * @return bool
 978          */
 979         public function isSpecial( $name ) {
 980                 if ( $this->isSpecialPage() ) {
 981                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 982                         if ( $name == $thisName ) {
 983                                 return true;
 984                         }
 985                 }
 986                 return false;
 987         }
 988
 989         /**
 990          * If the Title refers to a special page alias which is not the local default, resolve
 991          * the alias, and localise the name as necessary.  Otherwise, return $this
 992          *
 993          * @return Title
 994          */
 995         public function fixSpecialName() {
 996                 if ( $this->isSpecialPage() ) {
 997                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 998                         if ( $canonicalName ) {
 999                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1000                                 if ( $localName != $this->mDbkeyform ) {
1001                                         return Title::makeTitle( NS_SPECIAL, $localName );
1002                                 }
1003                         }
1004                 }
1005                 return $this;
1006         }
1007
1008         /**
1009          * Returns true if the title is inside the specified namespace.
1010          *
1011          * Please make use of this instead of comparing to getNamespace()
1012          * This function is much more resistant to changes we may make
1013          * to namespaces than code that makes direct comparisons.
1014          * @param int $ns The namespace
1015          * @return bool
1016          * @since 1.19
1017          */
1018         public function inNamespace( $ns ) {
1019                 return MWNamespace::equals( $this->getNamespace(), $ns );
1020         }
1021
1022         /**
1023          * Returns true if the title is inside one of the specified namespaces.
1024          *
1025          * @param ...$namespaces The namespaces to check for
1026          * @return bool
1027          * @since 1.19
1028          */
1029         public function inNamespaces( /* ... */ ) {
1030                 $namespaces = func_get_args();
1031                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1032                         $namespaces = $namespaces[0];
1033                 }
1034
1035                 foreach ( $namespaces as $ns ) {
1036                         if ( $this->inNamespace( $ns ) ) {
1037                                 return true;
1038                         }
1039                 }
1040
1041                 return false;
1042         }
1043
1044         /**
1045          * Returns true if the title has the same subject namespace as the
1046          * namespace specified.
1047          * For example this method will take NS_USER and return true if namespace
1048          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1049          * as their subject namespace.
1050          *
1051          * This is MUCH simpler than individually testing for equivalence
1052          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1053          * @since 1.19
1054          * @param int $ns
1055          * @return bool
1056          */
1057         public function hasSubjectNamespace( $ns ) {
1058                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1059         }
1060
1061         /**
1062          * Is this Title in a namespace which contains content?
1063          * In other words, is this a content page, for the purposes of calculating
1064          * statistics, etc?
1065          *
1066          * @return bool
1067          */
1068         public function isContentPage() {
1069                 return MWNamespace::isContent( $this->getNamespace() );
1070         }
1071
1072         /**
1073          * Would anybody with sufficient privileges be able to move this page?
1074          * Some pages just aren't movable.
1075          *
1076          * @return bool
1077          */
1078         public function isMovable() {
1079                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1080                         // Interwiki title or immovable namespace. Hooks don't get to override here
1081                         return false;
1082                 }
1083
1084                 $result = true;
1085                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1086                 return $result;
1087         }
1088
1089         /**
1090          * Is this the mainpage?
1091          * @note Title::newFromText seems to be sufficiently optimized by the title
1092          * cache that we don't need to over-optimize by doing direct comparisons and
1093          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1094          * ends up reporting something differently than $title->isMainPage();
1095          *
1096          * @since 1.18
1097          * @return bool
1098          */
1099         public function isMainPage() {
1100                 return $this->equals( Title::newMainPage() );
1101         }
1102
1103         /**
1104          * Is this a subpage?
1105          *
1106          * @return bool
1107          */
1108         public function isSubpage() {
1109                 return MWNamespace::hasSubpages( $this->mNamespace )
1110                         ? strpos( $this->getText(), '/' ) !== false
1111                         : false;
1112         }
1113
1114         /**
1115          * Is this a conversion table for the LanguageConverter?
1116          *
1117          * @return bool
1118          */
1119         public function isConversionTable() {
1120                 // @todo ConversionTable should become a separate content model.
1121
1122                 return $this->getNamespace() == NS_MEDIAWIKI &&
1123                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1124         }
1125
1126         /**
1127          * Does that page contain wikitext, or it is JS, CSS or whatever?
1128          *
1129          * @return bool
1130          */
1131         public function isWikitextPage() {
1132                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1133         }
1134
1135         /**
1136          * Could this page contain custom CSS or JavaScript for the global UI.
1137          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1138          * or CONTENT_MODEL_JAVASCRIPT.
1139          *
1140          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
1141          *
1142          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
1143          *
1144          * @return bool
1145          */
1146         public function isCssOrJsPage() {
1147                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1148                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1149                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1150
1151                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
1152                 #      hook functions can force this method to return true even outside the mediawiki namespace.
1153
1154                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1155
1156                 return $isCssOrJsPage;
1157         }
1158
1159         /**
1160          * Is this a .css or .js subpage of a user page?
1161          * @return bool
1162          */
1163         public function isCssJsSubpage() {
1164                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1165                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1166                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1167         }
1168
1169         /**
1170          * Trim down a .css or .js subpage title to get the corresponding skin name
1171          *
1172          * @return string Containing skin name from .css or .js subpage title
1173          */
1174         public function getSkinFromCssJsSubpage() {
1175                 $subpage = explode( '/', $this->mTextform );
1176                 $subpage = $subpage[count( $subpage ) - 1];
1177                 $lastdot = strrpos( $subpage, '.' );
1178                 if ( $lastdot === false ) {
1179                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1180                 }
1181                 return substr( $subpage, 0, $lastdot );
1182         }
1183
1184         /**
1185          * Is this a .css subpage of a user page?
1186          *
1187          * @return bool
1188          */
1189         public function isCssSubpage() {
1190                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1191                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1192         }
1193
1194         /**
1195          * Is this a .js subpage of a user page?
1196          *
1197          * @return bool
1198          */
1199         public function isJsSubpage() {
1200                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1201                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1202         }
1203
1204         /**
1205          * Is this a talk page of some sort?
1206          *
1207          * @return bool
1208          */
1209         public function isTalkPage() {
1210                 return MWNamespace::isTalk( $this->getNamespace() );
1211         }
1212
1213         /**
1214          * Get a Title object associated with the talk page of this article
1215          *
1216          * @return Title The object for the talk page
1217          */
1218         public function getTalkPage() {
1219                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1220         }
1221
1222         /**
1223          * Get a title object associated with the subject page of this
1224          * talk page
1225          *
1226          * @return Title The object for the subject page
1227          */
1228         public function getSubjectPage() {
1229                 // Is this the same title?
1230                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1231                 if ( $this->getNamespace() == $subjectNS ) {
1232                         return $this;
1233                 }
1234                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1235         }
1236
1237         /**
1238          * Get the default namespace index, for when there is no namespace
1239          *
1240          * @return int Default namespace index
1241          */
1242         public function getDefaultNamespace() {
1243                 return $this->mDefaultNamespace;
1244         }
1245
1246         /**
1247          * Get the Title fragment (i.e.\ the bit after the #) in text form
1248          *
1249          * Use Title::hasFragment to check for a fragment
1250          *
1251          * @return string Title fragment
1252          */
1253         public function getFragment() {
1254                 return $this->mFragment;
1255         }
1256
1257         /**
1258          * Check if a Title fragment is set
1259          *
1260          * @return bool
1261          * @since 1.23
1262          */
1263         public function hasFragment() {
1264                 return $this->mFragment !== '';
1265         }
1266
1267         /**
1268          * Get the fragment in URL form, including the "#" character if there is one
1269          * @return string Fragment in URL form
1270          */
1271         public function getFragmentForURL() {
1272                 if ( !$this->hasFragment() ) {
1273                         return '';
1274                 } else {
1275                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1276                 }
1277         }
1278
1279         /**
1280          * Set the fragment for this title. Removes the first character from the
1281          * specified fragment before setting, so it assumes you're passing it with
1282          * an initial "#".
1283          *
1284          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1285          * Still in active use privately.
1286          *
1287          * @param string $fragment Text
1288          */
1289         public function setFragment( $fragment ) {
1290                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1291         }
1292
1293         /**
1294          * Prefix some arbitrary text with the namespace or interwiki prefix
1295          * of this object
1296          *
1297          * @param string $name The text
1298          * @return string The prefixed text
1299          * @private
1300          */
1301         private function prefix( $name ) {
1302                 $p = '';
1303                 if ( $this->isExternal() ) {
1304                         $p = $this->mInterwiki . ':';
1305                 }
1306
1307                 if ( 0 != $this->mNamespace ) {
1308                         $p .= $this->getNsText() . ':';
1309                 }
1310                 return $p . $name;
1311         }
1312
1313         /**
1314          * Get the prefixed database key form
1315          *
1316          * @return string The prefixed title, with underscores and
1317          *  any interwiki and namespace prefixes
1318          */
1319         public function getPrefixedDBkey() {
1320                 $s = $this->prefix( $this->mDbkeyform );
1321                 $s = str_replace( ' ', '_', $s );
1322                 return $s;
1323         }
1324
1325         /**
1326          * Get the prefixed title with spaces.
1327          * This is the form usually used for display
1328          *
1329          * @return string The prefixed title, with spaces
1330          */
1331         public function getPrefixedText() {
1332                 if ( $this->mPrefixedText === null ) {
1333                         $s = $this->prefix( $this->mTextform );
1334                         $s = str_replace( '_', ' ', $s );
1335                         $this->mPrefixedText = $s;
1336                 }
1337                 return $this->mPrefixedText;
1338         }
1339
1340         /**
1341          * Return a string representation of this title
1342          *
1343          * @return string Representation of this title
1344          */
1345         public function __toString() {
1346                 return $this->getPrefixedText();
1347         }
1348
1349         /**
1350          * Get the prefixed title with spaces, plus any fragment
1351          * (part beginning with '#')
1352          *
1353          * @return string The prefixed title, with spaces and the fragment, including '#'
1354          */
1355         public function getFullText() {
1356                 $text = $this->getPrefixedText();
1357                 if ( $this->hasFragment() ) {
1358                         $text .= '#' . $this->getFragment();
1359                 }
1360                 return $text;
1361         }
1362
1363         /**
1364          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1365          *
1366          * @par Example:
1367          * @code
1368          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1369          * # returns: 'Foo'
1370          * @endcode
1371          *
1372          * @return string Root name
1373          * @since 1.20
1374          */
1375         public function getRootText() {
1376                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1377                         return $this->getText();
1378                 }
1379
1380                 return strtok( $this->getText(), '/' );
1381         }
1382
1383         /**
1384          * Get the root page name title, i.e. the leftmost part before any slashes
1385          *
1386          * @par Example:
1387          * @code
1388          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1389          * # returns: Title{User:Foo}
1390          * @endcode
1391          *
1392          * @return Title Root title
1393          * @since 1.20
1394          */
1395         public function getRootTitle() {
1396                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1397         }
1398
1399         /**
1400          * Get the base page name without a namespace, i.e. the part before the subpage name
1401          *
1402          * @par Example:
1403          * @code
1404          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1405          * # returns: 'Foo/Bar'
1406          * @endcode
1407          *
1408          * @return string Base name
1409          */
1410         public function getBaseText() {
1411                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1412                         return $this->getText();
1413                 }
1414
1415                 $parts = explode( '/', $this->getText() );
1416                 # Don't discard the real title if there's no subpage involved
1417                 if ( count( $parts ) > 1 ) {
1418                         unset( $parts[count( $parts ) - 1] );
1419                 }
1420                 return implode( '/', $parts );
1421         }
1422
1423         /**
1424          * Get the base page name title, i.e. the part before the subpage name
1425          *
1426          * @par Example:
1427          * @code
1428          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1429          * # returns: Title{User:Foo/Bar}
1430          * @endcode
1431          *
1432          * @return Title Base title
1433          * @since 1.20
1434          */
1435         public function getBaseTitle() {
1436                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1437         }
1438
1439         /**
1440          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1441          *
1442          * @par Example:
1443          * @code
1444          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1445          * # returns: "Baz"
1446          * @endcode
1447          *
1448          * @return string Subpage name
1449          */
1450         public function getSubpageText() {
1451                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1452                         return $this->mTextform;
1453                 }
1454                 $parts = explode( '/', $this->mTextform );
1455                 return $parts[count( $parts ) - 1];
1456         }
1457
1458         /**
1459          * Get the title for a subpage of the current page
1460          *
1461          * @par Example:
1462          * @code
1463          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1464          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1465          * @endcode
1466          *
1467          * @param string $text The subpage name to add to the title
1468          * @return Title Subpage title
1469          * @since 1.20
1470          */
1471         public function getSubpage( $text ) {
1472                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1473         }
1474
1475         /**
1476          * Get the HTML-escaped displayable text form.
1477          * Used for the title field in <a> tags.
1478          *
1479          * @return string The text, including any prefixes
1480          * @deprecated since 1.19
1481          */
1482         public function getEscapedText() {
1483                 wfDeprecated( __METHOD__, '1.19' );
1484                 return htmlspecialchars( $this->getPrefixedText() );
1485         }
1486
1487         /**
1488          * Get a URL-encoded form of the subpage text
1489          *
1490          * @return string URL-encoded subpage name
1491          */
1492         public function getSubpageUrlForm() {
1493                 $text = $this->getSubpageText();
1494                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1495                 return $text;
1496         }
1497
1498         /**
1499          * Get a URL-encoded title (not an actual URL) including interwiki
1500          *
1501          * @return string The URL-encoded form
1502          */
1503         public function getPrefixedURL() {
1504                 $s = $this->prefix( $this->mDbkeyform );
1505                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1506                 return $s;
1507         }
1508
1509         /**
1510          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1511          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1512          * second argument named variant. This was deprecated in favor
1513          * of passing an array of option with a "variant" key
1514          * Once $query2 is removed for good, this helper can be dropped
1515          * and the wfArrayToCgi moved to getLocalURL();
1516          *
1517          * @since 1.19 (r105919)
1518          * @param array|string $query
1519          * @param bool $query2
1520          * @return string
1521          */
1522         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1523                 if ( $query2 !== false ) {
1524                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1525                                 "method called with a second parameter is deprecated. Add your " .
1526                                 "parameter to an array passed as the first parameter.", "1.19" );
1527                 }
1528                 if ( is_array( $query ) ) {
1529                         $query = wfArrayToCgi( $query );
1530                 }
1531                 if ( $query2 ) {
1532                         if ( is_string( $query2 ) ) {
1533                                 // $query2 is a string, we will consider this to be
1534                                 // a deprecated $variant argument and add it to the query
1535                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1536                         } else {
1537                                 $query2 = wfArrayToCgi( $query2 );
1538                         }
1539                         // If we have $query content add a & to it first
1540                         if ( $query ) {
1541                                 $query .= '&';
1542                         }
1543                         // Now append the queries together
1544                         $query .= $query2;
1545                 }
1546                 return $query;
1547         }
1548
1549         /**
1550          * Get a real URL referring to this title, with interwiki link and
1551          * fragment
1552          *
1553          * @see self::getLocalURL for the arguments.
1554          * @see wfExpandUrl
1555          * @param array|string $query
1556          * @param bool $query2
1557          * @param string $proto Protocol type to use in URL
1558          * @return string The URL
1559          */
1560         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1561                 $query = self::fixUrlQueryArgs( $query, $query2 );
1562
1563                 # Hand off all the decisions on urls to getLocalURL
1564                 $url = $this->getLocalURL( $query );
1565
1566                 # Expand the url to make it a full url. Note that getLocalURL has the
1567                 # potential to output full urls for a variety of reasons, so we use
1568                 # wfExpandUrl instead of simply prepending $wgServer
1569                 $url = wfExpandUrl( $url, $proto );
1570
1571                 # Finally, add the fragment.
1572                 $url .= $this->getFragmentForURL();
1573
1574                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1575                 return $url;
1576         }
1577
1578         /**
1579          * Get a URL with no fragment or server name (relative URL) from a Title object.
1580          * If this page is generated with action=render, however,
1581          * $wgServer is prepended to make an absolute URL.
1582          *
1583          * @see self::getFullURL to always get an absolute URL.
1584          * @see self::newFromText to produce a Title object.
1585          *
1586          * @param string|array $query an optional query string,
1587          *   not used for interwiki links. Can be specified as an associative array as well,
1588          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1589          *   Some query patterns will trigger various shorturl path replacements.
1590          * @param array $query2 An optional secondary query array. This one MUST
1591          *   be an array. If a string is passed it will be interpreted as a deprecated
1592          *   variant argument and urlencoded into a variant= argument.
1593          *   This second query argument will be added to the $query
1594          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1595          *   pair in the first parameter array instead.
1596          *
1597          * @return string String of the URL.
1598          */
1599         public function getLocalURL( $query = '', $query2 = false ) {
1600                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1601
1602                 $query = self::fixUrlQueryArgs( $query, $query2 );
1603
1604                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1605                 if ( $interwiki ) {
1606                         $namespace = $this->getNsText();
1607                         if ( $namespace != '' ) {
1608                                 # Can this actually happen? Interwikis shouldn't be parsed.
1609                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1610                                 $namespace .= ':';
1611                         }
1612                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1613                         $url = wfAppendQuery( $url, $query );
1614                 } else {
1615                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1616                         if ( $query == '' ) {
1617                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1618                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1619                         } else {
1620                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1621                                 $url = false;
1622                                 $matches = array();
1623
1624                                 if ( !empty( $wgActionPaths )
1625                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1626                                 ) {
1627                                         $action = urldecode( $matches[2] );
1628                                         if ( isset( $wgActionPaths[$action] ) ) {
1629                                                 $query = $matches[1];
1630                                                 if ( isset( $matches[4] ) ) {
1631                                                         $query .= $matches[4];
1632                                                 }
1633                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1634                                                 if ( $query != '' ) {
1635                                                         $url = wfAppendQuery( $url, $query );
1636                                                 }
1637                                         }
1638                                 }
1639
1640                                 if ( $url === false
1641                                         && $wgVariantArticlePath
1642                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1643                                         && $this->getPageLanguage()->hasVariants()
1644                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1645                                 ) {
1646                                         $variant = urldecode( $matches[1] );
1647                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1648                                                 // Only do the variant replacement if the given variant is a valid
1649                                                 // variant for the page's language.
1650                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1651                                                 $url = str_replace( '$1', $dbkey, $url );
1652                                         }
1653                                 }
1654
1655                                 if ( $url === false ) {
1656                                         if ( $query == '-' ) {
1657                                                 $query = '';
1658                                         }
1659                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1660                                 }
1661                         }
1662
1663                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1664
1665                         // @todo FIXME: This causes breakage in various places when we
1666                         // actually expected a local URL and end up with dupe prefixes.
1667                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1668                                 $url = $wgServer . $url;
1669                         }
1670                 }
1671                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1672                 return $url;
1673         }
1674
1675         /**
1676          * Get a URL that's the simplest URL that will be valid to link, locally,
1677          * to the current Title.  It includes the fragment, but does not include
1678          * the server unless action=render is used (or the link is external).  If
1679          * there's a fragment but the prefixed text is empty, we just return a link
1680          * to the fragment.
1681          *
1682          * The result obviously should not be URL-escaped, but does need to be
1683          * HTML-escaped if it's being output in HTML.
1684          *
1685          * @param array $query
1686          * @param bool $query2
1687          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1688          * @see self::getLocalURL for the arguments.
1689          * @return string The URL
1690          */
1691         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1692                 wfProfileIn( __METHOD__ );
1693                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1694                         $ret = $this->getFullURL( $query, $query2, $proto );
1695                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1696                         $ret = $this->getFragmentForURL();
1697                 } else {
1698                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1699                 }
1700                 wfProfileOut( __METHOD__ );
1701                 return $ret;
1702         }
1703
1704         /**
1705          * Get an HTML-escaped version of the URL form, suitable for
1706          * using in a link, without a server name or fragment
1707          *
1708          * @see self::getLocalURL for the arguments.
1709          * @param string $query
1710          * @param bool|string $query2
1711          * @return string The URL
1712          * @deprecated since 1.19
1713          */
1714         public function escapeLocalURL( $query = '', $query2 = false ) {
1715                 wfDeprecated( __METHOD__, '1.19' );
1716                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1717         }
1718
1719         /**
1720          * Get an HTML-escaped version of the URL form, suitable for
1721          * using in a link, including the server name and fragment
1722          *
1723          * @see self::getLocalURL for the arguments.
1724          * @return string The URL
1725          * @deprecated since 1.19
1726          */
1727         public function escapeFullURL( $query = '', $query2 = false ) {
1728                 wfDeprecated( __METHOD__, '1.19' );
1729                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1730         }
1731
1732         /**
1733          * Get the URL form for an internal link.
1734          * - Used in various Squid-related code, in case we have a different
1735          * internal hostname for the server from the exposed one.
1736          *
1737          * This uses $wgInternalServer to qualify the path, or $wgServer
1738          * if $wgInternalServer is not set. If the server variable used is
1739          * protocol-relative, the URL will be expanded to http://
1740          *
1741          * @see self::getLocalURL for the arguments.
1742          * @return string The URL
1743          */
1744         public function getInternalURL( $query = '', $query2 = false ) {
1745                 global $wgInternalServer, $wgServer;
1746                 $query = self::fixUrlQueryArgs( $query, $query2 );
1747                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1748                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1749                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1750                 return $url;
1751         }
1752
1753         /**
1754          * Get the URL for a canonical link, for use in things like IRC and
1755          * e-mail notifications. Uses $wgCanonicalServer and the
1756          * GetCanonicalURL hook.
1757          *
1758          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1759          *
1760          * @see self::getLocalURL for the arguments.
1761          * @return string The URL
1762          * @since 1.18
1763          */
1764         public function getCanonicalURL( $query = '', $query2 = false ) {
1765                 $query = self::fixUrlQueryArgs( $query, $query2 );
1766                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1767                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1768                 return $url;
1769         }
1770
1771         /**
1772          * HTML-escaped version of getCanonicalURL()
1773          *
1774          * @see self::getLocalURL for the arguments.
1775          * @since 1.18
1776          * @return string
1777          * @deprecated since 1.19
1778          */
1779         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1780                 wfDeprecated( __METHOD__, '1.19' );
1781                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1782         }
1783
1784         /**
1785          * Get the edit URL for this Title
1786          *
1787          * @return string The URL, or a null string if this is an interwiki link
1788          */
1789         public function getEditURL() {
1790                 if ( $this->isExternal() ) {
1791                         return '';
1792                 }
1793                 $s = $this->getLocalURL( 'action=edit' );
1794
1795                 return $s;
1796         }
1797
1798         /**
1799          * Is $wgUser watching this page?
1800          *
1801          * @deprecated since 1.20; use User::isWatched() instead.
1802          * @return bool
1803          */
1804         public function userIsWatching() {
1805                 global $wgUser;
1806
1807                 if ( is_null( $this->mWatched ) ) {
1808                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1809                                 $this->mWatched = false;
1810                         } else {
1811                                 $this->mWatched = $wgUser->isWatched( $this );
1812                         }
1813                 }
1814                 return $this->mWatched;
1815         }
1816
1817         /**
1818          * Can $wgUser read this page?
1819          *
1820          * @deprecated since 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1821          * @return bool
1822          */
1823         public function userCanRead() {
1824                 wfDeprecated( __METHOD__, '1.19' );
1825                 return $this->userCan( 'read' );
1826         }
1827
1828         /**
1829          * Can $user perform $action on this page?
1830          * This skips potentially expensive cascading permission checks
1831          * as well as avoids expensive error formatting
1832          *
1833          * Suitable for use for nonessential UI controls in common cases, but
1834          * _not_ for functional access control.
1835          *
1836          * May provide false positives, but should never provide a false negative.
1837          *
1838          * @param string $action Action that permission needs to be checked for
1839          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1840          * @return bool
1841          */
1842         public function quickUserCan( $action, $user = null ) {
1843                 return $this->userCan( $action, $user, false );
1844         }
1845
1846         /**
1847          * Can $user perform $action on this page?
1848          *
1849          * @param string $action Action that permission needs to be checked for
1850          * @param User $user User to check (since 1.19); $wgUser will be used if not
1851          *   provided.
1852          * @param bool $doExpensiveQueries Set this to false to avoid doing
1853          *   unnecessary queries.
1854          * @return bool
1855          */
1856         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1857                 if ( !$user instanceof User ) {
1858                         global $wgUser;
1859                         $user = $wgUser;
1860                 }
1861                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1862         }
1863
1864         /**
1865          * Can $user perform $action on this page?
1866          *
1867          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1868          *
1869          * @param string $action action that permission needs to be checked for
1870          * @param User $user User to check
1871          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1872          *   queries by skipping checks for cascading protections and user blocks.
1873          * @param array $ignoreErrors of Strings Set this to a list of message keys
1874          *   whose corresponding errors may be ignored.
1875          * @return array Array of arguments to wfMessage to explain permissions problems.
1876          */
1877         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1878                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1879
1880                 // Remove the errors being ignored.
1881                 foreach ( $errors as $index => $error ) {
1882                         $error_key = is_array( $error ) ? $error[0] : $error;
1883
1884                         if ( in_array( $error_key, $ignoreErrors ) ) {
1885                                 unset( $errors[$index] );
1886                         }
1887                 }
1888
1889                 return $errors;
1890         }
1891
1892         /**
1893          * Permissions checks that fail most often, and which are easiest to test.
1894          *
1895          * @param string $action the action to check
1896          * @param User $user User to check
1897          * @param array $errors List of current errors
1898          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1899          * @param bool $short Short circuit on first error
1900          *
1901          * @return array List of errors
1902          */
1903         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1904                 if ( !wfRunHooks( 'TitleQuickPermissions', array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) ) ) {
1905                         return $errors;
1906                 }
1907
1908                 if ( $action == 'create' ) {
1909                         if (
1910                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1911                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1912                         ) {
1913                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1914                         }
1915                 } elseif ( $action == 'move' ) {
1916                         if ( !$user->isAllowed( 'move-rootuserpages' )
1917                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1918                                 // Show user page-specific message only if the user can move other pages
1919                                 $errors[] = array( 'cant-move-user-page' );
1920                         }
1921
1922                         // Check if user is allowed to move files if it's a file
1923                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1924                                 $errors[] = array( 'movenotallowedfile' );
1925                         }
1926
1927                         if ( !$user->isAllowed( 'move' ) ) {
1928                                 // User can't move anything
1929                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1930                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1931                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1932                                         // custom message if logged-in users without any special rights can move
1933                                         $errors[] = array( 'movenologintext' );
1934                                 } else {
1935                                         $errors[] = array( 'movenotallowed' );
1936                                 }
1937                         }
1938                 } elseif ( $action == 'move-target' ) {
1939                         if ( !$user->isAllowed( 'move' ) ) {
1940                                 // User can't move anything
1941                                 $errors[] = array( 'movenotallowed' );
1942                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1943                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1944                                 // Show user page-specific message only if the user can move other pages
1945                                 $errors[] = array( 'cant-move-to-user-page' );
1946                         }
1947                 } elseif ( !$user->isAllowed( $action ) ) {
1948                         $errors[] = $this->missingPermissionError( $action, $short );
1949                 }
1950
1951                 return $errors;
1952         }
1953
1954         /**
1955          * Add the resulting error code to the errors array
1956          *
1957          * @param array $errors List of current errors
1958          * @param array $result Result of errors
1959          *
1960          * @return array List of errors
1961          */
1962         private function resultToError( $errors, $result ) {
1963                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1964                         // A single array representing an error
1965                         $errors[] = $result;
1966                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1967                         // A nested array representing multiple errors
1968                         $errors = array_merge( $errors, $result );
1969                 } elseif ( $result !== '' && is_string( $result ) ) {
1970                         // A string representing a message-id
1971                         $errors[] = array( $result );
1972                 } elseif ( $result === false ) {
1973                         // a generic "We don't want them to do that"
1974                         $errors[] = array( 'badaccess-group0' );
1975                 }
1976                 return $errors;
1977         }
1978
1979         /**
1980          * Check various permission hooks
1981          *
1982          * @param string $action The action to check
1983          * @param User $user User to check
1984          * @param array $errors List of current errors
1985          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1986          * @param bool $short Short circuit on first error
1987          *
1988          * @return array List of errors
1989          */
1990         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1991                 // Use getUserPermissionsErrors instead
1992                 $result = '';
1993                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1994                         return $result ? array() : array( array( 'badaccess-group0' ) );
1995                 }
1996                 // Check getUserPermissionsErrors hook
1997                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1998                         $errors = $this->resultToError( $errors, $result );
1999                 }
2000                 // Check getUserPermissionsErrorsExpensive hook
2001                 if (
2002                         $doExpensiveQueries
2003                         && !( $short && count( $errors ) > 0 )
2004                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2005                 ) {
2006                         $errors = $this->resultToError( $errors, $result );
2007                 }
2008
2009                 return $errors;
2010         }
2011
2012         /**
2013          * Check permissions on special pages & namespaces
2014          *
2015          * @param string $action The action to check
2016          * @param User $user User to check
2017          * @param array $errors List of current errors
2018          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2019          * @param bool $short Short circuit on first error
2020          *
2021          * @return array List of errors
2022          */
2023         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2024                 # Only 'createaccount' can be performed on special pages,
2025                 # which don't actually exist in the DB.
2026                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2027                         $errors[] = array( 'ns-specialprotected' );
2028                 }
2029
2030                 # Check $wgNamespaceProtection for restricted namespaces
2031                 if ( $this->isNamespaceProtected( $user ) ) {
2032                         $ns = $this->mNamespace == NS_MAIN ?
2033                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2034                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2035                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
2036                 }
2037
2038                 return $errors;
2039         }
2040
2041         /**
2042          * Check CSS/JS sub-page permissions
2043          *
2044          * @param string $action The action to check
2045          * @param User $user User to check
2046          * @param array $errors List of current errors
2047          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2048          * @param bool $short Short circuit on first error
2049          *
2050          * @return array List of errors
2051          */
2052         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2053                 # Protect css/js subpages of user pages
2054                 # XXX: this might be better using restrictions
2055                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2056                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2057                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2058                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2059                                         $errors[] = array( 'mycustomcssprotected' );
2060                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2061                                         $errors[] = array( 'mycustomjsprotected' );
2062                                 }
2063                         } else {
2064                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2065                                         $errors[] = array( 'customcssprotected' );
2066                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2067                                         $errors[] = array( 'customjsprotected' );
2068                                 }
2069                         }
2070                 }
2071
2072                 return $errors;
2073         }
2074
2075         /**
2076          * Check against page_restrictions table requirements on this
2077          * page. The user must possess all required rights for this
2078          * action.
2079          *
2080          * @param string $action The action to check
2081          * @param User $user User to check
2082          * @param array $errors List of current errors
2083          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2084          * @param bool $short Short circuit on first error
2085          *
2086          * @return array List of errors
2087          */
2088         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2089                 foreach ( $this->getRestrictions( $action ) as $right ) {
2090                         // Backwards compatibility, rewrite sysop -> editprotected
2091                         if ( $right == 'sysop' ) {
2092                                 $right = 'editprotected';
2093                         }
2094                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2095                         if ( $right == 'autoconfirmed' ) {
2096                                 $right = 'editsemiprotected';
2097                         }
2098                         if ( $right == '' ) {
2099                                 continue;
2100                         }
2101                         if ( !$user->isAllowed( $right ) ) {
2102                                 $errors[] = array( 'protectedpagetext', $right );
2103                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2104                                 $errors[] = array( 'protectedpagetext', 'protect' );
2105                         }
2106                 }
2107
2108                 return $errors;
2109         }
2110
2111         /**
2112          * Check restrictions on cascading pages.
2113          *
2114          * @param string $action The action to check
2115          * @param User $user User to check
2116          * @param array $errors List of current errors
2117          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2118          * @param bool $short Short circuit on first error
2119          *
2120          * @return array List of errors
2121          */
2122         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2123                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2124                         # We /could/ use the protection level on the source page, but it's
2125                         # fairly ugly as we have to establish a precedence hierarchy for pages
2126                         # included by multiple cascade-protected pages. So just restrict
2127                         # it to people with 'protect' permission, as they could remove the
2128                         # protection anyway.
2129                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2130                         # Cascading protection depends on more than this page...
2131                         # Several cascading protected pages may include this page...
2132                         # Check each cascading level
2133                         # This is only for protection restrictions, not for all actions
2134                         if ( isset( $restrictions[$action] ) ) {
2135                                 foreach ( $restrictions[$action] as $right ) {
2136                                         // Backwards compatibility, rewrite sysop -> editprotected
2137                                         if ( $right == 'sysop' ) {
2138                                                 $right = 'editprotected';
2139                                         }
2140                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2141                                         if ( $right == 'autoconfirmed' ) {
2142                                                 $right = 'editsemiprotected';
2143                                         }
2144                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2145                                                 $pages = '';
2146                                                 foreach ( $cascadingSources as $page ) {
2147                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2148                                                 }
2149                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2150                                         }
2151                                 }
2152                         }
2153                 }
2154
2155                 return $errors;
2156         }
2157
2158         /**
2159          * Check action permissions not already checked in checkQuickPermissions
2160          *
2161          * @param string $action The action to check
2162          * @param User $user User to check
2163          * @param array $errors List of current errors
2164          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2165          * @param bool $short Short circuit on first error
2166          *
2167          * @return array List of errors
2168          */
2169         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2170                 global $wgDeleteRevisionsLimit, $wgLang;
2171
2172                 if ( $action == 'protect' ) {
2173                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
2174                                 // If they can't edit, they shouldn't protect.
2175                                 $errors[] = array( 'protect-cantedit' );
2176                         }
2177                 } elseif ( $action == 'create' ) {
2178                         $title_protection = $this->getTitleProtection();
2179                         if ( $title_protection ) {
2180                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2181                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2182                                 }
2183                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2184                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2185                                 }
2186                                 if ( $title_protection['pt_create_perm'] == ''
2187                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2188                                 ) {
2189                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2190                                 }
2191                         }
2192                 } elseif ( $action == 'move' ) {
2193                         // Check for immobile pages
2194                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2195                                 // Specific message for this case
2196                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2197                         } elseif ( !$this->isMovable() ) {
2198                                 // Less specific message for rarer cases
2199                                 $errors[] = array( 'immobile-source-page' );
2200                         }
2201                 } elseif ( $action == 'move-target' ) {
2202                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2203                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2204                         } elseif ( !$this->isMovable() ) {
2205                                 $errors[] = array( 'immobile-target-page' );
2206                         }
2207                 } elseif ( $action == 'delete' ) {
2208                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2209                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2210                         ) {
2211                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2212                         }
2213                 }
2214                 return $errors;
2215         }
2216
2217         /**
2218          * Check that the user isn't blocked from editing.
2219          *
2220          * @param string $action The action to check
2221          * @param User $user User to check
2222          * @param array $errors List of current errors
2223          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2224          * @param bool $short Short circuit on first error
2225          *
2226          * @return array List of errors
2227          */
2228         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2229                 // Account creation blocks handled at userlogin.
2230                 // Unblocking handled in SpecialUnblock
2231                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2232                         return $errors;
2233                 }
2234
2235                 global $wgEmailConfirmToEdit;
2236
2237                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2238                         $errors[] = array( 'confirmedittext' );
2239                 }
2240
2241                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2242                         // Don't block the user from editing their own talk page unless they've been
2243                         // explicitly blocked from that too.
2244                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2245                         // @todo FIXME: Pass the relevant context into this function.
2246                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2247                 }
2248
2249                 return $errors;
2250         }
2251
2252         /**
2253          * Check that the user is allowed to read this page.
2254          *
2255          * @param string $action The action to check
2256          * @param User $user User to check
2257          * @param array $errors List of current errors
2258          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2259          * @param bool $short Short circuit on first error
2260          *
2261          * @return array List of errors
2262          */
2263         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2264                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2265
2266                 $whitelisted = false;
2267                 if ( User::isEveryoneAllowed( 'read' ) ) {
2268                         # Shortcut for public wikis, allows skipping quite a bit of code
2269                         $whitelisted = true;
2270                 } elseif ( $user->isAllowed( 'read' ) ) {
2271                         # If the user is allowed to read pages, he is allowed to read all pages
2272                         $whitelisted = true;
2273                 } elseif ( $this->isSpecial( 'Userlogin' )
2274                         || $this->isSpecial( 'ChangePassword' )
2275                         || $this->isSpecial( 'PasswordReset' )
2276                 ) {
2277                         # Always grant access to the login page.
2278                         # Even anons need to be able to log in.
2279                         $whitelisted = true;
2280                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2281                         # Time to check the whitelist
2282                         # Only do these checks is there's something to check against
2283                         $name = $this->getPrefixedText();
2284                         $dbName = $this->getPrefixedDBkey();
2285
2286                         // Check for explicit whitelisting with and without underscores
2287                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2288                                 $whitelisted = true;
2289                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2290                                 # Old settings might have the title prefixed with
2291                                 # a colon for main-namespace pages
2292                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2293                                         $whitelisted = true;
2294                                 }
2295                         } elseif ( $this->isSpecialPage() ) {
2296                                 # If it's a special page, ditch the subpage bit and check again
2297                                 $name = $this->getDBkey();
2298                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2299                                 if ( $name ) {
2300                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2301                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2302                                                 $whitelisted = true;
2303                                         }
2304                                 }
2305                         }
2306                 }
2307
2308                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2309                         $name = $this->getPrefixedText();
2310                         // Check for regex whitelisting
2311                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2312                                 if ( preg_match( $listItem, $name ) ) {
2313                                         $whitelisted = true;
2314                                         break;
2315                                 }
2316                         }
2317                 }
2318
2319                 if ( !$whitelisted ) {
2320                         # If the title is not whitelisted, give extensions a chance to do so...
2321                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2322                         if ( !$whitelisted ) {
2323                                 $errors[] = $this->missingPermissionError( $action, $short );
2324                         }
2325                 }
2326
2327                 return $errors;
2328         }
2329
2330         /**
2331          * Get a description array when the user doesn't have the right to perform
2332          * $action (i.e. when User::isAllowed() returns false)
2333          *
2334          * @param string $action The action to check
2335          * @param bool $short Short circuit on first error
2336          * @return array List of errors
2337          */
2338         private function missingPermissionError( $action, $short ) {
2339                 // We avoid expensive display logic for quickUserCan's and such
2340                 if ( $short ) {
2341                         return array( 'badaccess-group0' );
2342                 }
2343
2344                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2345                         User::getGroupsWithPermission( $action ) );
2346
2347                 if ( count( $groups ) ) {
2348                         global $wgLang;
2349                         return array(
2350                                 'badaccess-groups',
2351                                 $wgLang->commaList( $groups ),
2352                                 count( $groups )
2353                         );
2354                 } else {
2355                         return array( 'badaccess-group0' );
2356                 }
2357         }
2358
2359         /**
2360          * Can $user perform $action on this page? This is an internal function,
2361          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2362          * checks on wfReadOnly() and blocks)
2363          *
2364          * @param string $action Action that permission needs to be checked for
2365          * @param User $user User to check
2366          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2367          * @param bool $short Set this to true to stop after the first permission error.
2368          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2369          */
2370         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2371                 wfProfileIn( __METHOD__ );
2372
2373                 # Read has special handling
2374                 if ( $action == 'read' ) {
2375                         $checks = array(
2376                                 'checkPermissionHooks',
2377                                 'checkReadPermissions',
2378                         );
2379                 } else {
2380                         $checks = array(
2381                                 'checkQuickPermissions',
2382                                 'checkPermissionHooks',
2383                                 'checkSpecialsAndNSPermissions',
2384                                 'checkCSSandJSPermissions',
2385                                 'checkPageRestrictions',
2386                                 'checkCascadingSourcesRestrictions',
2387                                 'checkActionPermissions',
2388                                 'checkUserBlock'
2389                         );
2390                 }
2391
2392                 $errors = array();
2393                 while ( count( $checks ) > 0 &&
2394                                 !( $short && count( $errors ) > 0 ) ) {
2395                         $method = array_shift( $checks );
2396                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2397                 }
2398
2399                 wfProfileOut( __METHOD__ );
2400                 return $errors;
2401         }
2402
2403         /**
2404          * Get a filtered list of all restriction types supported by this wiki.
2405          * @param bool $exists True to get all restriction types that apply to
2406          * titles that do exist, False for all restriction types that apply to
2407          * titles that do not exist
2408          * @return array
2409          */
2410         public static function getFilteredRestrictionTypes( $exists = true ) {
2411                 global $wgRestrictionTypes;
2412                 $types = $wgRestrictionTypes;
2413                 if ( $exists ) {
2414                         # Remove the create restriction for existing titles
2415                         $types = array_diff( $types, array( 'create' ) );
2416                 } else {
2417                         # Only the create and upload restrictions apply to non-existing titles
2418                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2419                 }
2420                 return $types;
2421         }
2422
2423         /**
2424          * Returns restriction types for the current Title
2425          *
2426          * @return array Applicable restriction types
2427          */
2428         public function getRestrictionTypes() {
2429                 if ( $this->isSpecialPage() ) {
2430                         return array();
2431                 }
2432
2433                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2434
2435                 if ( $this->getNamespace() != NS_FILE ) {
2436                         # Remove the upload restriction for non-file titles
2437                         $types = array_diff( $types, array( 'upload' ) );
2438                 }
2439
2440                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2441
2442                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2443                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2444
2445                 return $types;
2446         }
2447
2448         /**
2449          * Is this title subject to title protection?
2450          * Title protection is the one applied against creation of such title.
2451          *
2452          * @return array|bool An associative array representing any existent title
2453          *   protection, or false if there's none.
2454          */
2455         private function getTitleProtection() {
2456                 // Can't protect pages in special namespaces
2457                 if ( $this->getNamespace() < 0 ) {
2458                         return false;
2459                 }
2460
2461                 // Can't protect pages that exist.
2462                 if ( $this->exists() ) {
2463                         return false;
2464                 }
2465
2466                 if ( !isset( $this->mTitleProtection ) ) {
2467                         $dbr = wfGetDB( DB_SLAVE );
2468                         $res = $dbr->select(
2469                                 'protected_titles',
2470                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2471                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2472                                 __METHOD__
2473                         );
2474
2475                         // fetchRow returns false if there are no rows.
2476                         $this->mTitleProtection = $dbr->fetchRow( $res );
2477                 }
2478                 return $this->mTitleProtection;
2479         }
2480
2481         /**
2482          * Update the title protection status
2483          *
2484          * @deprecated since 1.19; use WikiPage::doUpdateRestrictions() instead.
2485          * @param string $create_perm Permission required for creation
2486          * @param string $reason Reason for protection
2487          * @param string $expiry Expiry timestamp
2488          * @return bool
2489          */
2490         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2491                 wfDeprecated( __METHOD__, '1.19' );
2492
2493                 global $wgUser;
2494
2495                 $limit = array( 'create' => $create_perm );
2496                 $expiry = array( 'create' => $expiry );
2497
2498                 $page = WikiPage::factory( $this );
2499                 $cascade = false;
2500                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2501
2502                 return $status->isOK();
2503         }
2504
2505         /**
2506          * Remove any title protection due to page existing
2507          */
2508         public function deleteTitleProtection() {
2509                 $dbw = wfGetDB( DB_MASTER );
2510
2511                 $dbw->delete(
2512                         'protected_titles',
2513                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2514                         __METHOD__
2515                 );
2516                 $this->mTitleProtection = false;
2517         }
2518
2519         /**
2520          * Is this page "semi-protected" - the *only* protection levels are listed
2521          * in $wgSemiprotectedRestrictionLevels?
2522          *
2523          * @param string $action Action to check (default: edit)
2524          * @return bool
2525          */
2526         public function isSemiProtected( $action = 'edit' ) {
2527                 global $wgSemiprotectedRestrictionLevels;
2528
2529                 $restrictions = $this->getRestrictions( $action );
2530                 $semi = $wgSemiprotectedRestrictionLevels;
2531                 if ( !$restrictions || !$semi ) {
2532                         // Not protected, or all protection is full protection
2533                         return false;
2534                 }
2535
2536                 // Remap autoconfirmed to editsemiprotected for BC
2537                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2538                         $semi[$key] = 'editsemiprotected';
2539                 }
2540                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2541                         $restrictions[$key] = 'editsemiprotected';
2542                 }
2543
2544                 return !array_diff( $restrictions, $semi );
2545         }
2546
2547         /**
2548          * Does the title correspond to a protected article?
2549          *
2550          * @param string $action the action the page is protected from,
2551          * by default checks all actions.
2552          * @return bool
2553          */
2554         public function isProtected( $action = '' ) {
2555                 global $wgRestrictionLevels;
2556
2557                 $restrictionTypes = $this->getRestrictionTypes();
2558
2559                 # Special pages have inherent protection
2560                 if ( $this->isSpecialPage() ) {
2561                         return true;
2562                 }
2563
2564                 # Check regular protection levels
2565                 foreach ( $restrictionTypes as $type ) {
2566                         if ( $action == $type || $action == '' ) {
2567                                 $r = $this->getRestrictions( $type );
2568                                 foreach ( $wgRestrictionLevels as $level ) {
2569                                         if ( in_array( $level, $r ) && $level != '' ) {
2570                                                 return true;
2571                                         }
2572                                 }
2573                         }
2574                 }
2575
2576                 return false;
2577         }
2578
2579         /**
2580          * Determines if $user is unable to edit this page because it has been protected
2581          * by $wgNamespaceProtection.
2582          *
2583          * @param User $user User object to check permissions
2584          * @return bool
2585          */
2586         public function isNamespaceProtected( User $user ) {
2587                 global $wgNamespaceProtection;
2588
2589                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2590                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2591                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2592                                         return true;
2593                                 }
2594                         }
2595                 }
2596                 return false;
2597         }
2598
2599         /**
2600          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2601          *
2602          * @return bool If the page is subject to cascading restrictions.
2603          */
2604         public function isCascadeProtected() {
2605                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2606                 return ( $sources > 0 );
2607         }
2608
2609         /**
2610          * Determines whether cascading protection sources have already been loaded from
2611          * the database.
2612          *
2613          * @param bool $getPages True to check if the pages are loaded, or false to check
2614          * if the status is loaded.
2615          * @return bool Whether or not the specified information has been loaded
2616          * @since 1.23
2617          */
2618         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2619                 return $getPages ? isset( $this->mCascadeSources ) : isset( $this->mHasCascadingRestrictions );
2620         }
2621
2622         /**
2623          * Cascading protection: Get the source of any cascading restrictions on this page.
2624          *
2625          * @param bool $getPages Whether or not to retrieve the actual pages
2626          *        that the restrictions have come from.
2627          * @return array|bool Array of Title objects of the pages from which cascading restrictions
2628          *     have come, false for none, or true if such restrictions exist, but $getPages
2629          *     was not set.  The restriction array is an array of each type, each of which
2630          *     contains a array of unique groups.
2631          */
2632         public function getCascadeProtectionSources( $getPages = true ) {
2633                 global $wgContLang;
2634                 $pagerestrictions = array();
2635
2636                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2637                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2638                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2639                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2640                 }
2641
2642                 wfProfileIn( __METHOD__ );
2643
2644                 $dbr = wfGetDB( DB_SLAVE );
2645
2646                 if ( $this->getNamespace() == NS_FILE ) {
2647                         $tables = array( 'imagelinks', 'page_restrictions' );
2648                         $where_clauses = array(
2649                                 'il_to' => $this->getDBkey(),
2650                                 'il_from=pr_page',
2651                                 'pr_cascade' => 1
2652                         );
2653                 } else {
2654                         $tables = array( 'templatelinks', 'page_restrictions' );
2655                         $where_clauses = array(
2656                                 'tl_namespace' => $this->getNamespace(),
2657                                 'tl_title' => $this->getDBkey(),
2658                                 'tl_from=pr_page',
2659                                 'pr_cascade' => 1
2660                         );
2661                 }
2662
2663                 if ( $getPages ) {
2664                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2665                                 'pr_expiry', 'pr_type', 'pr_level' );
2666                         $where_clauses[] = 'page_id=pr_page';
2667                         $tables[] = 'page';
2668                 } else {
2669                         $cols = array( 'pr_expiry' );
2670                 }
2671
2672                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2673
2674                 $sources = $getPages ? array() : false;
2675                 $now = wfTimestampNow();
2676                 $purgeExpired = false;
2677
2678                 foreach ( $res as $row ) {
2679                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2680                         if ( $expiry > $now ) {
2681                                 if ( $getPages ) {
2682                                         $page_id = $row->pr_page;
2683                                         $page_ns = $row->page_namespace;
2684                                         $page_title = $row->page_title;
2685                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2686                                         # Add groups needed for each restriction type if its not already there
2687                                         # Make sure this restriction type still exists
2688
2689                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2690                                                 $pagerestrictions[$row->pr_type] = array();
2691                                         }
2692
2693                                         if (
2694                                                 isset( $pagerestrictions[$row->pr_type] )
2695                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2696                                         ) {
2697                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2698                                         }
2699                                 } else {
2700                                         $sources = true;
2701                                 }
2702                         } else {
2703                                 // Trigger lazy purge of expired restrictions from the db
2704                                 $purgeExpired = true;
2705                         }
2706                 }
2707                 if ( $purgeExpired ) {
2708                         Title::purgeExpiredRestrictions();
2709                 }
2710
2711                 if ( $getPages ) {
2712                         $this->mCascadeSources = $sources;
2713                         $this->mCascadingRestrictions = $pagerestrictions;
2714                 } else {
2715                         $this->mHasCascadingRestrictions = $sources;
2716                 }
2717
2718                 wfProfileOut( __METHOD__ );
2719                 return array( $sources, $pagerestrictions );
2720         }
2721
2722         /**
2723          * Accessor for mRestrictionsLoaded
2724          *
2725          * @return bool Whether or not the page's restrictions have already been
2726          * loaded from the database
2727          * @since 1.23
2728          */
2729         public function areRestrictionsLoaded() {
2730                 return $this->mRestrictionsLoaded;
2731         }
2732
2733         /**
2734          * Accessor/initialisation for mRestrictions
2735          *
2736          * @param string $action Action that permission needs to be checked for
2737          * @return array Array of Strings the array of groups allowed to edit this article
2738          */
2739         public function getRestrictions( $action ) {
2740                 if ( !$this->mRestrictionsLoaded ) {
2741                         $this->loadRestrictions();
2742                 }
2743                 return isset( $this->mRestrictions[$action] )
2744                                 ? $this->mRestrictions[$action]
2745                                 : array();
2746         }
2747
2748         /**
2749          * Accessor/initialisation for mRestrictions
2750          *
2751          * @return array Array of Arrays of Strings the first level indexed by
2752          * action, the second level containing the names of the groups
2753          * allowed to perform each action
2754          * @since 1.23
2755          */
2756         public function getAllRestrictions() {
2757                 if ( !$this->mRestrictionsLoaded ) {
2758                         $this->loadRestrictions();
2759                 }
2760                 return $this->mRestrictions;
2761         }
2762
2763         /**
2764          * Get the expiry time for the restriction against a given action
2765          *
2766          * @param string $action
2767          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2768          *     or not protected at all, or false if the action is not recognised.
2769          */
2770         public function getRestrictionExpiry( $action ) {
2771                 if ( !$this->mRestrictionsLoaded ) {
2772                         $this->loadRestrictions();
2773                 }
2774                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2775         }
2776
2777         /**
2778          * Returns cascading restrictions for the current article
2779          *
2780          * @return bool
2781          */
2782         function areRestrictionsCascading() {
2783                 if ( !$this->mRestrictionsLoaded ) {
2784                         $this->loadRestrictions();
2785                 }
2786
2787                 return $this->mCascadeRestriction;
2788         }
2789
2790         /**
2791          * Loads a string into mRestrictions array
2792          *
2793          * @param ResultWrapper $res Resource restrictions as an SQL result.
2794          * @param string $oldFashionedRestrictions Comma-separated list of page
2795          *        restrictions from page table (pre 1.10)
2796          */
2797         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2798                 $rows = array();
2799
2800                 foreach ( $res as $row ) {
2801                         $rows[] = $row;
2802                 }
2803
2804                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2805         }
2806
2807         /**
2808          * Compiles list of active page restrictions from both page table (pre 1.10)
2809          * and page_restrictions table for this existing page.
2810          * Public for usage by LiquidThreads.
2811          *
2812          * @param array $rows Array of db result objects
2813          * @param string $oldFashionedRestrictions Comma-separated list of page
2814          *   restrictions from page table (pre 1.10)
2815          */
2816         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2817                 global $wgContLang;
2818                 $dbr = wfGetDB( DB_SLAVE );
2819
2820                 $restrictionTypes = $this->getRestrictionTypes();
2821
2822                 foreach ( $restrictionTypes as $type ) {
2823                         $this->mRestrictions[$type] = array();
2824                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2825                 }
2826
2827                 $this->mCascadeRestriction = false;
2828
2829                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2830
2831                 if ( $oldFashionedRestrictions === null ) {
2832                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2833                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2834                 }
2835
2836                 if ( $oldFashionedRestrictions != '' ) {
2837
2838                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2839                                 $temp = explode( '=', trim( $restrict ) );
2840                                 if ( count( $temp ) == 1 ) {
2841                                         // old old format should be treated as edit/move restriction
2842                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2843                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2844                                 } else {
2845                                         $restriction = trim( $temp[1] );
2846                                         if ( $restriction != '' ) { //some old entries are empty
2847                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2848                                         }
2849                                 }
2850                         }
2851
2852                         $this->mOldRestrictions = true;
2853
2854                 }
2855
2856                 if ( count( $rows ) ) {
2857                         # Current system - load second to make them override.
2858                         $now = wfTimestampNow();
2859                         $purgeExpired = false;
2860
2861                         # Cycle through all the restrictions.
2862                         foreach ( $rows as $row ) {
2863
2864                                 // Don't take care of restrictions types that aren't allowed
2865                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2866                                         continue;
2867                                 }
2868
2869                                 // This code should be refactored, now that it's being used more generally,
2870                                 // But I don't really see any harm in leaving it in Block for now -werdna
2871                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2872
2873                                 // Only apply the restrictions if they haven't expired!
2874                                 if ( !$expiry || $expiry > $now ) {
2875                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2876                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2877
2878                                         $this->mCascadeRestriction |= $row->pr_cascade;
2879                                 } else {
2880                                         // Trigger a lazy purge of expired restrictions
2881                                         $purgeExpired = true;
2882                                 }
2883                         }
2884
2885                         if ( $purgeExpired ) {
2886                                 Title::purgeExpiredRestrictions();
2887                         }
2888                 }
2889
2890                 $this->mRestrictionsLoaded = true;
2891         }
2892
2893         /**
2894          * Load restrictions from the page_restrictions table
2895          *
2896          * @param string $oldFashionedRestrictions Comma-separated list of page
2897          *   restrictions from page table (pre 1.10)
2898          */
2899         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2900                 global $wgContLang;
2901                 if ( !$this->mRestrictionsLoaded ) {
2902                         if ( $this->exists() ) {
2903                                 $dbr = wfGetDB( DB_SLAVE );
2904
2905                                 $res = $dbr->select(
2906                                         'page_restrictions',
2907                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2908                                         array( 'pr_page' => $this->getArticleID() ),
2909                                         __METHOD__
2910                                 );
2911
2912                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2913                         } else {
2914                                 $title_protection = $this->getTitleProtection();
2915
2916                                 if ( $title_protection ) {
2917                                         $now = wfTimestampNow();
2918                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2919
2920                                         if ( !$expiry || $expiry > $now ) {
2921                                                 // Apply the restrictions
2922                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2923                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2924                                         } else { // Get rid of the old restrictions
2925                                                 Title::purgeExpiredRestrictions();
2926                                                 $this->mTitleProtection = false;
2927                                         }
2928                                 } else {
2929                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2930                                 }
2931                                 $this->mRestrictionsLoaded = true;
2932                         }
2933                 }
2934         }
2935
2936         /**
2937          * Flush the protection cache in this object and force reload from the database.
2938          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2939          */
2940         public function flushRestrictions() {
2941                 $this->mRestrictionsLoaded = false;
2942                 $this->mTitleProtection = null;
2943         }
2944
2945         /**
2946          * Purge expired restrictions from the page_restrictions table
2947          */
2948         static function purgeExpiredRestrictions() {
2949                 if ( wfReadOnly() ) {
2950                         return;
2951                 }
2952
2953                 $method = __METHOD__;
2954                 $dbw = wfGetDB( DB_MASTER );
2955                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
2956                         $dbw->delete(
2957                                 'page_restrictions',
2958                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2959                                 $method
2960                         );
2961                         $dbw->delete(
2962                                 'protected_titles',
2963                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2964                                 $method
2965                         );
2966                 } );
2967         }
2968
2969         /**
2970          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2971          *
2972          * @return bool
2973          */
2974         public function hasSubpages() {
2975                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2976                         # Duh
2977                         return false;
2978                 }
2979
2980                 # We dynamically add a member variable for the purpose of this method
2981                 # alone to cache the result.  There's no point in having it hanging
2982                 # around uninitialized in every Title object; therefore we only add it
2983                 # if needed and don't declare it statically.
2984                 if ( !isset( $this->mHasSubpages ) ) {
2985                         $this->mHasSubpages = false;
2986                         $subpages = $this->getSubpages( 1 );
2987                         if ( $subpages instanceof TitleArray ) {
2988                                 $this->mHasSubpages = (bool)$subpages->count();
2989                         }
2990                 }
2991
2992                 return $this->mHasSubpages;
2993         }
2994
2995         /**
2996          * Get all subpages of this page.
2997          *
2998          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
2999          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3000          *  doesn't allow subpages
3001          */
3002         public function getSubpages( $limit = -1 ) {
3003                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3004                         return array();
3005                 }
3006
3007                 $dbr = wfGetDB( DB_SLAVE );
3008                 $conds['page_namespace'] = $this->getNamespace();
3009                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3010                 $options = array();
3011                 if ( $limit > -1 ) {
3012                         $options['LIMIT'] = $limit;
3013                 }
3014                 $this->mSubpages = TitleArray::newFromResult(
3015                         $dbr->select( 'page',
3016                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3017                                 $conds,
3018                                 __METHOD__,
3019                                 $options
3020                         )
3021                 );
3022                 return $this->mSubpages;
3023         }
3024
3025         /**
3026          * Is there a version of this page in the deletion archive?
3027          *
3028          * @return int The number of archived revisions
3029          */
3030         public function isDeleted() {
3031                 if ( $this->getNamespace() < 0 ) {
3032                         $n = 0;
3033                 } else {
3034                         $dbr = wfGetDB( DB_SLAVE );
3035
3036                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3037                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3038                                 __METHOD__
3039                         );
3040                         if ( $this->getNamespace() == NS_FILE ) {
3041                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3042                                         array( 'fa_name' => $this->getDBkey() ),
3043                                         __METHOD__
3044                                 );
3045                         }
3046                 }
3047                 return (int)$n;
3048         }
3049
3050         /**
3051          * Is there a version of this page in the deletion archive?
3052          *
3053          * @return bool
3054          */
3055         public function isDeletedQuick() {
3056                 if ( $this->getNamespace() < 0 ) {
3057                         return false;
3058                 }
3059                 $dbr = wfGetDB( DB_SLAVE );
3060                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3061                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3062                         __METHOD__
3063                 );
3064                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3065                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3066                                 array( 'fa_name' => $this->getDBkey() ),
3067                                 __METHOD__
3068                         );
3069                 }
3070                 return $deleted;
3071         }
3072
3073         /**
3074          * Get the article ID for this Title from the link cache,
3075          * adding it if necessary
3076          *
3077          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3078          *  for update
3079          * @return int The ID
3080          */
3081         public function getArticleID( $flags = 0 ) {
3082                 if ( $this->getNamespace() < 0 ) {
3083                         $this->mArticleID = 0;
3084                         return $this->mArticleID;
3085                 }
3086                 $linkCache = LinkCache::singleton();
3087                 if ( $flags & self::GAID_FOR_UPDATE ) {
3088                         $oldUpdate = $linkCache->forUpdate( true );
3089                         $linkCache->clearLink( $this );
3090                         $this->mArticleID = $linkCache->addLinkObj( $this );
3091                         $linkCache->forUpdate( $oldUpdate );
3092                 } else {
3093                         if ( -1 == $this->mArticleID ) {
3094                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3095                         }
3096                 }
3097                 return $this->mArticleID;
3098         }
3099
3100         /**
3101          * Is this an article that is a redirect page?
3102          * Uses link cache, adding it if necessary
3103          *
3104          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3105          * @return bool
3106          */
3107         public function isRedirect( $flags = 0 ) {
3108                 if ( !is_null( $this->mRedirect ) ) {
3109                         return $this->mRedirect;
3110                 }
3111                 # Calling getArticleID() loads the field from cache as needed
3112                 if ( !$this->getArticleID( $flags ) ) {
3113                         $this->mRedirect = false;
3114                         return $this->mRedirect;
3115                 }
3116
3117                 $linkCache = LinkCache::singleton();
3118                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3119                 if ( $cached === null ) {
3120                         # Trust LinkCache's state over our own
3121                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3122                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3123                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3124                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3125                         # LinkCache to refresh its data from the master.
3126                         $this->mRedirect = false;
3127                         return $this->mRedirect;
3128                 }
3129
3130                 $this->mRedirect = (bool)$cached;
3131
3132                 return $this->mRedirect;
3133         }
3134
3135         /**
3136          * What is the length of this page?
3137          * Uses link cache, adding it if necessary
3138          *
3139          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3140          * @return int
3141          */
3142         public function getLength( $flags = 0 ) {
3143                 if ( $this->mLength != -1 ) {
3144                         return $this->mLength;
3145                 }
3146                 # Calling getArticleID() loads the field from cache as needed
3147                 if ( !$this->getArticleID( $flags ) ) {
3148                         $this->mLength = 0;
3149                         return $this->mLength;
3150                 }
3151                 $linkCache = LinkCache::singleton();
3152                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3153                 if ( $cached === null ) {
3154                         # Trust LinkCache's state over our own, as for isRedirect()
3155                         $this->mLength = 0;
3156                         return $this->mLength;
3157                 }
3158
3159                 $this->mLength = intval( $cached );
3160
3161                 return $this->mLength;
3162         }
3163
3164         /**
3165          * What is the page_latest field for this page?
3166          *
3167          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3168          * @return int Int or 0 if the page doesn't exist
3169          */
3170         public function getLatestRevID( $flags = 0 ) {
3171                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3172                         return intval( $this->mLatestID );
3173                 }
3174                 # Calling getArticleID() loads the field from cache as needed
3175                 if ( !$this->getArticleID( $flags ) ) {
3176                         $this->mLatestID = 0;
3177                         return $this->mLatestID;
3178                 }
3179                 $linkCache = LinkCache::singleton();
3180                 $linkCache->addLinkObj( $this );
3181                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3182                 if ( $cached === null ) {
3183                         # Trust LinkCache's state over our own, as for isRedirect()
3184                         $this->mLatestID = 0;
3185                         return $this->mLatestID;
3186                 }
3187
3188                 $this->mLatestID = intval( $cached );
3189
3190                 return $this->mLatestID;
3191         }
3192
3193         /**
3194          * This clears some fields in this object, and clears any associated
3195          * keys in the "bad links" section of the link cache.
3196          *
3197          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3198          * loading of the new page_id. It's also called from
3199          * WikiPage::doDeleteArticleReal()
3200          *
3201          * @param int $newid The new Article ID
3202          */
3203         public function resetArticleID( $newid ) {
3204                 $linkCache = LinkCache::singleton();
3205                 $linkCache->clearLink( $this );
3206
3207                 if ( $newid === false ) {
3208                         $this->mArticleID = -1;
3209                 } else {
3210                         $this->mArticleID = intval( $newid );
3211                 }
3212                 $this->mRestrictionsLoaded = false;
3213                 $this->mRestrictions = array();
3214                 $this->mRedirect = null;
3215                 $this->mLength = -1;
3216                 $this->mLatestID = false;
3217                 $this->mContentModel = false;
3218                 $this->mEstimateRevisions = null;
3219                 $this->mPageLanguage = false;
3220         }
3221
3222         /**
3223          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3224          *
3225          * @param string $text Containing title to capitalize
3226          * @param int $ns Namespace index, defaults to NS_MAIN
3227          * @return string Containing capitalized title
3228          */
3229         public static function capitalize( $text, $ns = NS_MAIN ) {
3230                 global $wgContLang;
3231
3232                 if ( MWNamespace::isCapitalized( $ns ) ) {
3233                         return $wgContLang->ucfirst( $text );
3234                 } else {
3235                         return $text;
3236                 }
3237         }
3238
3239         /**
3240          * Secure and split - main initialisation function for this object
3241          *
3242          * Assumes that mDbkeyform has been set, and is urldecoded
3243          * and uses underscores, but not otherwise munged.  This function
3244          * removes illegal characters, splits off the interwiki and
3245          * namespace prefixes, sets the other forms, and canonicalizes
3246          * everything.
3247          *
3248          * @return bool True on success
3249          */
3250         private function secureAndSplit() {
3251                 # Initialisation
3252                 $this->mInterwiki = '';
3253                 $this->mFragment = '';
3254                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3255
3256                 $dbkey = $this->mDbkeyform;
3257
3258                 try {
3259                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3260                         //        the parsing code with Title, while avoiding massive refactoring.
3261                         // @todo: get rid of secureAndSplit, refactor parsing code.
3262                         $parser = $this->getTitleParser();
3263                         $parts = $parser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3264                 } catch ( MalformedTitleException $ex ) {
3265                         return false;
3266                 }
3267
3268                 # Fill fields
3269                 $this->setFragment( '#' . $parts['fragment'] );
3270                 $this->mInterwiki = $parts['interwiki'];
3271                 $this->mNamespace = $parts['namespace'];
3272                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3273
3274                 $this->mDbkeyform = $parts['dbkey'];
3275                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3276                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3277
3278                 # We already know that some pages won't be in the database!
3279                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3280                         $this->mArticleID = 0;
3281                 }
3282
3283                 return true;
3284         }
3285
3286         /**
3287          * Get an array of Title objects linking to this Title
3288          * Also stores the IDs in the link cache.
3289          *
3290          * WARNING: do not use this function on arbitrary user-supplied titles!
3291          * On heavily-used templates it will max out the memory.
3292          *
3293          * @param array $options May be FOR UPDATE
3294          * @param string $table Table name
3295          * @param string $prefix Fields prefix
3296          * @return Title[] Array of Title objects linking here
3297          */
3298         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3299                 if ( count( $options ) > 0 ) {
3300                         $db = wfGetDB( DB_MASTER );
3301                 } else {
3302                         $db = wfGetDB( DB_SLAVE );
3303                 }
3304
3305                 $res = $db->select(
3306                         array( 'page', $table ),
3307                         self::getSelectFields(),
3308                         array(
3309                                 "{$prefix}_from=page_id",
3310                                 "{$prefix}_namespace" => $this->getNamespace(),
3311                                 "{$prefix}_title" => $this->getDBkey() ),
3312                         __METHOD__,
3313                         $options
3314                 );
3315
3316                 $retVal = array();
3317                 if ( $res->numRows() ) {
3318                         $linkCache = LinkCache::singleton();
3319                         foreach ( $res as $row ) {
3320                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3321                                 if ( $titleObj ) {
3322                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3323                                         $retVal[] = $titleObj;
3324                                 }
3325                         }
3326                 }
3327                 return $retVal;
3328         }
3329
3330         /**
3331          * Get an array of Title objects using this Title as a template
3332          * Also stores the IDs in the link cache.
3333          *
3334          * WARNING: do not use this function on arbitrary user-supplied titles!
3335          * On heavily-used templates it will max out the memory.
3336          *
3337          * @param array $options May be FOR UPDATE
3338          * @return Title[] Array of Title the Title objects linking here
3339          */
3340         public function getTemplateLinksTo( $options = array() ) {
3341                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3342         }
3343
3344         /**
3345          * Get an array of Title objects linked from this Title
3346          * Also stores the IDs in the link cache.
3347          *
3348          * WARNING: do not use this function on arbitrary user-supplied titles!
3349          * On heavily-used templates it will max out the memory.
3350          *
3351          * @param array $options May be FOR UPDATE
3352          * @param string $table Table name
3353          * @param string $prefix Fields prefix
3354          * @return array Array of Title objects linking here
3355          */
3356         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3357                 global $wgContentHandlerUseDB;
3358
3359                 $id = $this->getArticleID();
3360
3361                 # If the page doesn't exist; there can't be any link from this page
3362                 if ( !$id ) {
3363                         return array();
3364                 }
3365
3366                 if ( count( $options ) > 0 ) {
3367                         $db = wfGetDB( DB_MASTER );
3368                 } else {
3369                         $db = wfGetDB( DB_SLAVE );
3370                 }
3371
3372                 $namespaceFiled = "{$prefix}_namespace";
3373                 $titleField = "{$prefix}_title";
3374
3375                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3376                 if ( $wgContentHandlerUseDB ) {
3377                         $fields[] = 'page_content_model';
3378                 }
3379
3380                 $res = $db->select(
3381                         array( $table, 'page' ),
3382                         $fields,
3383                         array( "{$prefix}_from" => $id ),
3384                         __METHOD__,
3385                         $options,
3386                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3387                 );
3388
3389                 $retVal = array();
3390                 if ( $res->numRows() ) {
3391                         $linkCache = LinkCache::singleton();
3392                         foreach ( $res as $row ) {
3393                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3394                                 if ( $titleObj ) {
3395                                         if ( $row->page_id ) {
3396                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3397                                         } else {
3398                                                 $linkCache->addBadLinkObj( $titleObj );
3399                                         }
3400                                         $retVal[] = $titleObj;
3401                                 }
3402                         }
3403                 }
3404                 return $retVal;
3405         }
3406
3407         /**
3408          * Get an array of Title objects used on this Title as a template
3409          * Also stores the IDs in the link cache.
3410          *
3411          * WARNING: do not use this function on arbitrary user-supplied titles!
3412          * On heavily-used templates it will max out the memory.
3413          *
3414          * @param array $options May be FOR UPDATE
3415          * @return Title[] Array of Title the Title objects used here
3416          */
3417         public function getTemplateLinksFrom( $options = array() ) {
3418                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3419         }
3420
3421         /**
3422          * Get an array of Title objects referring to non-existent articles linked from this page
3423          *
3424          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3425          * @return Title[] Array of Title the Title objects
3426          */
3427         public function getBrokenLinksFrom() {
3428                 if ( $this->getArticleID() == 0 ) {
3429                         # All links from article ID 0 are false positives
3430                         return array();
3431                 }
3432
3433                 $dbr = wfGetDB( DB_SLAVE );
3434                 $res = $dbr->select(
3435                         array( 'page', 'pagelinks' ),
3436                         array( 'pl_namespace', 'pl_title' ),
3437                         array(
3438                                 'pl_from' => $this->getArticleID(),
3439                                 'page_namespace IS NULL'
3440                         ),
3441                         __METHOD__, array(),
3442                         array(
3443                                 'page' => array(
3444                                         'LEFT JOIN',
3445                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3446                                 )
3447                         )
3448                 );
3449
3450                 $retVal = array();
3451                 foreach ( $res as $row ) {
3452                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3453                 }
3454                 return $retVal;
3455         }
3456
3457         /**
3458          * Get a list of URLs to purge from the Squid cache when this
3459          * page changes
3460          *
3461          * @return string[] Array of String the URLs
3462          */
3463         public function getSquidURLs() {
3464                 $urls = array(
3465                         $this->getInternalURL(),
3466                         $this->getInternalURL( 'action=history' )
3467                 );
3468
3469                 $pageLang = $this->getPageLanguage();
3470                 if ( $pageLang->hasVariants() ) {
3471                         $variants = $pageLang->getVariants();
3472                         foreach ( $variants as $vCode ) {
3473                                 $urls[] = $this->getInternalURL( '', $vCode );
3474                         }
3475                 }
3476
3477                 // If we are looking at a css/js user subpage, purge the action=raw.
3478                 if ( $this->isJsSubpage() ) {
3479                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3480                 } elseif ( $this->isCssSubpage() ) {
3481                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3482                 }
3483
3484                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3485                 return $urls;
3486         }
3487
3488         /**
3489          * Purge all applicable Squid URLs
3490          */
3491         public function purgeSquid() {
3492                 global $wgUseSquid;
3493                 if ( $wgUseSquid ) {
3494                         $urls = $this->getSquidURLs();
3495                         $u = new SquidUpdate( $urls );
3496                         $u->doUpdate();
3497                 }
3498         }
3499
3500         /**
3501          * Move this page without authentication
3502          *
3503          * @param Title $nt The new page Title
3504          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3505          */
3506         public function moveNoAuth( &$nt ) {
3507                 return $this->moveTo( $nt, false );
3508         }
3509
3510         /**
3511          * Check whether a given move operation would be valid.
3512          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3513          *
3514          * @param Title $nt The new title
3515          * @param bool $auth Indicates whether $wgUser's permissions
3516          *  should be checked
3517          * @param string $reason Is the log summary of the move, used for spam checking
3518          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3519          */
3520         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3521                 global $wgUser, $wgContentHandlerUseDB;
3522
3523                 $errors = array();
3524                 if ( !$nt ) {
3525                         // Normally we'd add this to $errors, but we'll get
3526                         // lots of syntax errors if $nt is not an object
3527                         return array( array( 'badtitletext' ) );
3528                 }
3529                 if ( $this->equals( $nt ) ) {
3530                         $errors[] = array( 'selfmove' );
3531                 }
3532                 if ( !$this->isMovable() ) {
3533                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3534                 }
3535                 if ( $nt->isExternal() ) {
3536                         $errors[] = array( 'immobile-target-namespace-iw' );
3537                 }
3538                 if ( !$nt->isMovable() ) {
3539                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3540                 }
3541
3542                 $oldid = $this->getArticleID();
3543                 $newid = $nt->getArticleID();
3544
3545                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3546                         $errors[] = array( 'articleexists' );
3547                 }
3548                 if (
3549                         ( $this->getDBkey() == '' ) ||
3550                         ( !$oldid ) ||
3551                         ( $nt->getDBkey() == '' )
3552                 ) {
3553                         $errors[] = array( 'badarticleerror' );
3554                 }
3555
3556                 // Content model checks
3557                 if ( !$wgContentHandlerUseDB &&
3558                                 $this->getContentModel() !== $nt->getContentModel() ) {
3559                         // can't move a page if that would change the page's content model
3560                         $errors[] = array(
3561                                 'bad-target-model',
3562                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3563                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3564                         );
3565                 }
3566
3567                 // Image-specific checks
3568                 if ( $this->getNamespace() == NS_FILE ) {
3569                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3570                 }
3571
3572                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3573                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3574                 }
3575
3576                 if ( $auth ) {
3577                         $errors = wfMergeErrorArrays( $errors,
3578                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3579                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3580                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3581                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3582                 }
3583
3584                 $match = EditPage::matchSummarySpamRegex( $reason );
3585                 if ( $match !== false ) {
3586                         // This is kind of lame, won't display nice
3587                         $errors[] = array( 'spamprotectiontext' );
3588                 }
3589
3590                 $err = null;
3591                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3592                         $errors[] = array( 'hookaborted', $err );
3593                 }
3594
3595                 # The move is allowed only if (1) the target doesn't exist, or
3596                 # (2) the target is a redirect to the source, and has no history
3597                 # (so we can undo bad moves right after they're done).
3598
3599                 if ( 0 != $newid ) { # Target exists; check for validity
3600                         if ( !$this->isValidMoveTarget( $nt ) ) {
3601                                 $errors[] = array( 'articleexists' );
3602                         }
3603                 } else {
3604                         $tp = $nt->getTitleProtection();
3605                         $right = $tp['pt_create_perm'];
3606                         if ( $right == 'sysop' ) {
3607                                 $right = 'editprotected'; // B/C
3608                         }
3609                         if ( $right == 'autoconfirmed' ) {
3610                                 $right = 'editsemiprotected'; // B/C
3611                         }
3612                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3613                                 $errors[] = array( 'cantmove-titleprotected' );
3614                         }
3615                 }
3616                 if ( empty( $errors ) ) {
3617                         return true;
3618                 }
3619                 return $errors;
3620         }
3621
3622         /**
3623          * Check if the requested move target is a valid file move target
3624          * @param Title $nt Target title
3625          * @return array List of errors
3626          */
3627         protected function validateFileMoveOperation( $nt ) {
3628                 global $wgUser;
3629
3630                 $errors = array();
3631
3632                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3633
3634                 $file = wfLocalFile( $this );
3635                 if ( $file->exists() ) {
3636                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3637                                 $errors[] = array( 'imageinvalidfilename' );
3638                         }
3639                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3640                                 $errors[] = array( 'imagetypemismatch' );
3641                         }
3642                 }
3643
3644                 if ( $nt->getNamespace() != NS_FILE ) {
3645                         $errors[] = array( 'imagenocrossnamespace' );
3646                         // From here we want to do checks on a file object, so if we can't
3647                         // create one, we must return.
3648                         return $errors;
3649                 }
3650
3651                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3652
3653                 $destFile = wfLocalFile( $nt );
3654                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3655                         $errors[] = array( 'file-exists-sharedrepo' );
3656                 }
3657
3658                 return $errors;
3659         }
3660
3661         /**
3662          * Move a title to a new location
3663          *
3664          * @param Title $nt The new title
3665          * @param bool $auth Indicates whether $wgUser's permissions
3666          *  should be checked
3667          * @param string $reason The reason for the move
3668          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3669          *  Ignored if the user doesn't have the suppressredirect right.
3670          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3671          */
3672         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3673                 global $wgUser;
3674                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3675                 if ( is_array( $err ) ) {
3676                         // Auto-block user's IP if the account was "hard" blocked
3677                         $wgUser->spreadAnyEditBlock();
3678                         return $err;
3679                 }
3680                 // Check suppressredirect permission
3681                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3682                         $createRedirect = true;
3683                 }
3684
3685                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3686
3687                 // If it is a file, move it first.
3688                 // It is done before all other moving stuff is done because it's hard to revert.
3689                 $dbw = wfGetDB( DB_MASTER );
3690                 if ( $this->getNamespace() == NS_FILE ) {
3691                         $file = wfLocalFile( $this );
3692                         if ( $file->exists() ) {
3693                                 $status = $file->move( $nt );
3694                                 if ( !$status->isOk() ) {
3695                                         return $status->getErrorsArray();
3696                                 }
3697                         }
3698                         // Clear RepoGroup process cache
3699                         RepoGroup::singleton()->clearCache( $this );
3700                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3701                 }
3702
3703                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3704                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3705                 $protected = $this->isProtected();
3706
3707                 // Do the actual move
3708                 $this->moveToInternal( $nt, $reason, $createRedirect );
3709
3710                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3711                 // cl_timestamp, which may disturb time-based lists on some sites.
3712                 $prefixes = $dbw->select(
3713                         'categorylinks',
3714                         array( 'cl_sortkey_prefix', 'cl_to' ),
3715                         array( 'cl_from' => $pageid ),
3716                         __METHOD__
3717                 );
3718                 foreach ( $prefixes as $prefixRow ) {
3719                         $prefix = $prefixRow->cl_sortkey_prefix;
3720                         $catTo = $prefixRow->cl_to;
3721                         $dbw->update( 'categorylinks',
3722                                 array(
3723                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3724                                                 $nt->getCategorySortkey( $prefix ) ),
3725                                         'cl_timestamp=cl_timestamp' ),
3726                                 array(
3727                                         'cl_from' => $pageid,
3728                                         'cl_to' => $catTo ),
3729                                 __METHOD__
3730                         );
3731                 }
3732
3733                 $redirid = $this->getArticleID();
3734
3735                 if ( $protected ) {
3736                         # Protect the redirect title as the title used to be...
3737                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3738                                 array(
3739                                         'pr_page' => $redirid,
3740                                         'pr_type' => 'pr_type',
3741                                         'pr_level' => 'pr_level',
3742                                         'pr_cascade' => 'pr_cascade',
3743                                         'pr_user' => 'pr_user',
3744                                         'pr_expiry' => 'pr_expiry'
3745                                 ),
3746                                 array( 'pr_page' => $pageid ),
3747                                 __METHOD__,
3748                                 array( 'IGNORE' )
3749                         );
3750                         # Update the protection log
3751                         $log = new LogPage( 'protect' );
3752                         $comment = wfMessage(
3753                                 'prot_1movedto2',
3754                                 $this->getPrefixedText(),
3755                                 $nt->getPrefixedText()
3756                         )->inContentLanguage()->text();
3757                         if ( $reason ) {
3758                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3759                         }
3760                         // @todo FIXME: $params?
3761                         $logId = $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ), $wgUser );
3762
3763                         // reread inserted pr_ids for log relation
3764                         $insertedPrIds = $dbw->select(
3765                                 'page_restrictions',
3766                                 'pr_id',
3767                                 array( 'pr_page' => $redirid ),
3768                                 __METHOD__
3769                         );
3770                         $logRelationsValues = array();
3771                         foreach ( $insertedPrIds as $prid ) {
3772                                 $logRelationsValues[] = $prid->pr_id;
3773                         }
3774                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3775                 }
3776
3777                 # Update watchlists
3778                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3779                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3780                 $oldtitle = $this->getDBkey();
3781                 $newtitle = $nt->getDBkey();
3782
3783                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3784                         WatchedItem::duplicateEntries( $this, $nt );
3785                 }
3786
3787                 $dbw->commit( __METHOD__ );
3788
3789                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3790                 return true;
3791         }
3792
3793         /**
3794          * Move page to a title which is either a redirect to the
3795          * source page or nonexistent
3796          *
3797          * @param Title $nt The page to move to, which should be a redirect or nonexistent
3798          * @param string $reason The reason for the move
3799          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3800          *   if the user has the suppressredirect right
3801          * @throws MWException
3802          */
3803         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3804                 global $wgUser, $wgContLang;
3805
3806                 if ( $nt->exists() ) {
3807                         $moveOverRedirect = true;
3808                         $logType = 'move_redir';
3809                 } else {
3810                         $moveOverRedirect = false;
3811                         $logType = 'move';
3812                 }
3813
3814                 if ( $createRedirect ) {
3815                         $contentHandler = ContentHandler::getForTitle( $this );
3816                         $redirectContent = $contentHandler->makeRedirectContent( $nt,
3817                                 wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3818
3819                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3820                 } else {
3821                         $redirectContent = null;
3822                 }
3823
3824                 $logEntry = new ManualLogEntry( 'move', $logType );
3825                 $logEntry->setPerformer( $wgUser );
3826                 $logEntry->setTarget( $this );
3827                 $logEntry->setComment( $reason );
3828                 $logEntry->setParameters( array(
3829                         '4::target' => $nt->getPrefixedText(),
3830                         '5::noredir' => $redirectContent ? '0': '1',
3831                 ) );
3832
3833                 $formatter = LogFormatter::newFromEntry( $logEntry );
3834                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3835                 $comment = $formatter->getPlainActionText();
3836                 if ( $reason ) {
3837                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3838                 }
3839                 # Truncate for whole multibyte characters.
3840                 $comment = $wgContLang->truncate( $comment, 255 );
3841
3842                 $oldid = $this->getArticleID();
3843
3844                 $dbw = wfGetDB( DB_MASTER );
3845
3846                 $newpage = WikiPage::factory( $nt );
3847
3848                 if ( $moveOverRedirect ) {
3849                         $newid = $nt->getArticleID();
3850                         $newcontent = $newpage->getContent();
3851
3852                         # Delete the old redirect. We don't save it to history since
3853                         # by definition if we've got here it's rather uninteresting.
3854                         # We have to remove it so that the next step doesn't trigger
3855                         # a conflict on the unique namespace+title index...
3856                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3857
3858                         $newpage->doDeleteUpdates( $newid, $newcontent );
3859                 }
3860
3861                 # Save a null revision in the page's history notifying of the move
3862                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true, $wgUser );
3863                 if ( !is_object( $nullRevision ) ) {
3864                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3865                 }
3866
3867                 $nullRevision->insertOn( $dbw );
3868
3869                 # Change the name of the target page:
3870                 $dbw->update( 'page',
3871                         /* SET */ array(
3872                                 'page_namespace' => $nt->getNamespace(),
3873                                 'page_title' => $nt->getDBkey(),
3874                         ),
3875                         /* WHERE */ array( 'page_id' => $oldid ),
3876                         __METHOD__
3877                 );
3878
3879                 // clean up the old title before reset article id - bug 45348
3880                 if ( !$redirectContent ) {
3881                         WikiPage::onArticleDelete( $this );
3882                 }
3883
3884                 $this->resetArticleID( 0 ); // 0 == non existing
3885                 $nt->resetArticleID( $oldid );
3886                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3887
3888                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3889
3890                 wfRunHooks( 'NewRevisionFromEditComplete',
3891                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3892
3893                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3894
3895                 if ( !$moveOverRedirect ) {
3896                         WikiPage::onArticleCreate( $nt );
3897                 }
3898
3899                 # Recreate the redirect, this time in the other direction.
3900                 if ( $redirectContent ) {
3901                         $redirectArticle = WikiPage::factory( $this );
3902                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
3903                         $newid = $redirectArticle->insertOn( $dbw );
3904                         if ( $newid ) { // sanity
3905                                 $this->resetArticleID( $newid );
3906                                 $redirectRevision = new Revision( array(
3907                                         'title' => $this, // for determining the default content model
3908                                         'page' => $newid,
3909                                         'user_text' => $wgUser->getName(),
3910                                         'user' => $wgUser->getId(),
3911                                         'comment' => $comment,
3912                                         'content' => $redirectContent ) );
3913                                 $redirectRevision->insertOn( $dbw );
3914                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3915
3916                                 wfRunHooks( 'NewRevisionFromEditComplete',
3917                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3918
3919                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3920                         }
3921                 }
3922
3923                 # Log the move
3924                 $logid = $logEntry->insert();
3925                 $logEntry->publish( $logid );
3926         }
3927
3928         /**
3929          * Move this page's subpages to be subpages of $nt
3930          *
3931          * @param Title $nt Move target
3932          * @param bool $auth Whether $wgUser's permissions should be checked
3933          * @param string $reason The reason for the move
3934          * @param bool $createRedirect Whether to create redirects from the old subpages to
3935          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3936          * @return array Array with old page titles as keys, and strings (new page titles) or
3937          *     arrays (errors) as values, or an error array with numeric indices if no pages
3938          *     were moved
3939          */
3940         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3941                 global $wgMaximumMovedPages;
3942                 // Check permissions
3943                 if ( !$this->userCan( 'move-subpages' ) ) {
3944                         return array( 'cant-move-subpages' );
3945                 }
3946                 // Do the source and target namespaces support subpages?
3947                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3948                         return array( 'namespace-nosubpages',
3949                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3950                 }
3951                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3952                         return array( 'namespace-nosubpages',
3953                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3954                 }
3955
3956                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3957                 $retval = array();
3958                 $count = 0;
3959                 foreach ( $subpages as $oldSubpage ) {
3960                         $count++;
3961                         if ( $count > $wgMaximumMovedPages ) {
3962                                 $retval[$oldSubpage->getPrefixedText()] =
3963                                                 array( 'movepage-max-pages',
3964                                                         $wgMaximumMovedPages );
3965                                 break;
3966                         }
3967
3968                         // We don't know whether this function was called before
3969                         // or after moving the root page, so check both
3970                         // $this and $nt
3971                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3972                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3973                         ) {
3974                                 // When moving a page to a subpage of itself,
3975                                 // don't move it twice
3976                                 continue;
3977                         }
3978                         $newPageName = preg_replace(
3979                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3980                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3981                                         $oldSubpage->getDBkey() );
3982                         if ( $oldSubpage->isTalkPage() ) {
3983                                 $newNs = $nt->getTalkPage()->getNamespace();
3984                         } else {
3985                                 $newNs = $nt->getSubjectPage()->getNamespace();
3986                         }
3987                         # Bug 14385: we need makeTitleSafe because the new page names may
3988                         # be longer than 255 characters.
3989                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3990
3991                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3992                         if ( $success === true ) {
3993                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3994                         } else {
3995                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3996                         }
3997                 }
3998                 return $retval;
3999         }
4000
4001         /**
4002          * Checks if this page is just a one-rev redirect.
4003          * Adds lock, so don't use just for light purposes.
4004          *
4005          * @return bool
4006          */
4007         public function isSingleRevRedirect() {
4008                 global $wgContentHandlerUseDB;
4009
4010                 $dbw = wfGetDB( DB_MASTER );
4011
4012                 # Is it a redirect?
4013                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4014                 if ( $wgContentHandlerUseDB ) {
4015                         $fields[] = 'page_content_model';
4016                 }
4017
4018                 $row = $dbw->selectRow( 'page',
4019                         $fields,
4020                         $this->pageCond(),
4021                         __METHOD__,
4022                         array( 'FOR UPDATE' )
4023                 );
4024                 # Cache some fields we may want
4025                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4026                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4027                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4028                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
4029                 if ( !$this->mRedirect ) {
4030                         return false;
4031                 }
4032                 # Does the article have a history?
4033                 $row = $dbw->selectField( array( 'page', 'revision' ),
4034                         'rev_id',
4035                         array( 'page_namespace' => $this->getNamespace(),
4036                                 'page_title' => $this->getDBkey(),
4037                                 'page_id=rev_page',
4038                                 'page_latest != rev_id'
4039                         ),
4040                         __METHOD__,
4041                         array( 'FOR UPDATE' )
4042                 );
4043                 # Return true if there was no history
4044                 return ( $row === false );
4045         }
4046
4047         /**
4048          * Checks if $this can be moved to a given Title
4049          * - Selects for update, so don't call it unless you mean business
4050          *
4051          * @param Title $nt The new title to check
4052          * @return bool
4053          */
4054         public function isValidMoveTarget( $nt ) {
4055                 # Is it an existing file?
4056                 if ( $nt->getNamespace() == NS_FILE ) {
4057                         $file = wfLocalFile( $nt );
4058                         if ( $file->exists() ) {
4059                                 wfDebug( __METHOD__ . ": file exists\n" );
4060                                 return false;
4061                         }
4062                 }
4063                 # Is it a redirect with no history?
4064                 if ( !$nt->isSingleRevRedirect() ) {
4065                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4066                         return false;
4067                 }
4068                 # Get the article text
4069                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4070                 if ( !is_object( $rev ) ) {
4071                         return false;
4072                 }
4073                 $content = $rev->getContent();
4074                 # Does the redirect point to the source?
4075                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4076                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4077
4078                 if ( $redirTitle ) {
4079                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4080                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4081                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4082                                 return false;
4083                         } else {
4084                                 return true;
4085                         }
4086                 } else {
4087                         # Fail safe (not a redirect after all. strange.)
4088                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4089                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4090                         return false;
4091                 }
4092         }
4093
4094         /**
4095          * Get categories to which this Title belongs and return an array of
4096          * categories' names.
4097          *
4098          * @return array Array of parents in the form:
4099          *        $parent => $currentarticle
4100          */
4101         public function getParentCategories() {
4102                 global $wgContLang;
4103
4104                 $data = array();
4105
4106                 $titleKey = $this->getArticleID();
4107
4108                 if ( $titleKey === 0 ) {
4109                         return $data;
4110                 }
4111
4112                 $dbr = wfGetDB( DB_SLAVE );
4113
4114                 $res = $dbr->select(
4115                         'categorylinks',
4116                         'cl_to',
4117                         array( 'cl_from' => $titleKey ),
4118                         __METHOD__
4119                 );
4120
4121                 if ( $res->numRows() > 0 ) {
4122                         foreach ( $res as $row ) {
4123                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4124                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4125                         }
4126                 }
4127                 return $data;
4128         }
4129
4130         /**
4131          * Get a tree of parent categories
4132          *
4133          * @param array $children Array with the children in the keys, to check for circular refs
4134          * @return array Tree of parent categories
4135          */
4136         public function getParentCategoryTree( $children = array() ) {
4137                 $stack = array();
4138                 $parents = $this->getParentCategories();
4139
4140                 if ( $parents ) {
4141                         foreach ( $parents as $parent => $current ) {
4142                                 if ( array_key_exists( $parent, $children ) ) {
4143                                         # Circular reference
4144                                         $stack[$parent] = array();
4145                                 } else {
4146                                         $nt = Title::newFromText( $parent );
4147                                         if ( $nt ) {
4148                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4149                                         }
4150                                 }
4151                         }
4152                 }
4153
4154                 return $stack;
4155         }
4156
4157         /**
4158          * Get an associative array for selecting this title from
4159          * the "page" table
4160          *
4161          * @return array Array suitable for the $where parameter of DB::select()
4162          */
4163         public function pageCond() {
4164                 if ( $this->mArticleID > 0 ) {
4165                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4166                         return array( 'page_id' => $this->mArticleID );
4167                 } else {
4168                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4169                 }
4170         }
4171
4172         /**
4173          * Get the revision ID of the previous revision
4174          *
4175          * @param int $revId Revision ID. Get the revision that was before this one.
4176          * @param int $flags Title::GAID_FOR_UPDATE
4177          * @return int|bool Old revision ID, or false if none exists
4178          */
4179         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4180                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4181                 $revId = $db->selectField( 'revision', 'rev_id',
4182                         array(
4183                                 'rev_page' => $this->getArticleID( $flags ),
4184                                 'rev_id < ' . intval( $revId )
4185                         ),
4186                         __METHOD__,
4187                         array( 'ORDER BY' => 'rev_id DESC' )
4188                 );
4189
4190                 if ( $revId === false ) {
4191                         return false;
4192                 } else {
4193                         return intval( $revId );
4194                 }
4195         }
4196
4197         /**
4198          * Get the revision ID of the next revision
4199          *
4200          * @param int $revId Revision ID. Get the revision that was after this one.
4201          * @param int $flags Title::GAID_FOR_UPDATE
4202          * @return int|bool Next revision ID, or false if none exists
4203          */
4204         public function getNextRevisionID( $revId, $flags = 0 ) {
4205                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4206                 $revId = $db->selectField( 'revision', 'rev_id',
4207                         array(
4208                                 'rev_page' => $this->getArticleID( $flags ),
4209                                 'rev_id > ' . intval( $revId )
4210                         ),
4211                         __METHOD__,
4212                         array( 'ORDER BY' => 'rev_id' )
4213                 );
4214
4215                 if ( $revId === false ) {
4216                         return false;
4217                 } else {
4218                         return intval( $revId );
4219                 }
4220         }
4221
4222         /**
4223          * Get the first revision of the page
4224          *
4225          * @param int $flags Title::GAID_FOR_UPDATE
4226          * @return Revision|null If page doesn't exist
4227          */
4228         public function getFirstRevision( $flags = 0 ) {
4229                 $pageId = $this->getArticleID( $flags );
4230                 if ( $pageId ) {
4231                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4232                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4233                                 array( 'rev_page' => $pageId ),
4234                                 __METHOD__,
4235                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4236                         );
4237                         if ( $row ) {
4238                                 return new Revision( $row );
4239                         }
4240                 }
4241                 return null;
4242         }
4243
4244         /**
4245          * Get the oldest revision timestamp of this page
4246          *
4247          * @param int $flags Title::GAID_FOR_UPDATE
4248          * @return string MW timestamp
4249          */
4250         public function getEarliestRevTime( $flags = 0 ) {
4251                 $rev = $this->getFirstRevision( $flags );
4252                 return $rev ? $rev->getTimestamp() : null;
4253         }
4254
4255         /**
4256          * Check if this is a new page
4257          *
4258          * @return bool
4259          */
4260         public function isNewPage() {
4261                 $dbr = wfGetDB( DB_SLAVE );
4262                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4263         }
4264
4265         /**
4266          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4267          *
4268          * @return bool
4269          */
4270         public function isBigDeletion() {
4271                 global $wgDeleteRevisionsLimit;
4272
4273                 if ( !$wgDeleteRevisionsLimit ) {
4274                         return false;
4275                 }
4276
4277                 $revCount = $this->estimateRevisionCount();
4278                 return $revCount > $wgDeleteRevisionsLimit;
4279         }
4280
4281         /**
4282          * Get the  approximate revision count of this page.
4283          *
4284          * @return int
4285          */
4286         public function estimateRevisionCount() {
4287                 if ( !$this->exists() ) {
4288                         return 0;
4289                 }
4290
4291                 if ( $this->mEstimateRevisions === null ) {
4292                         $dbr = wfGetDB( DB_SLAVE );
4293                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4294                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4295                 }
4296
4297                 return $this->mEstimateRevisions;
4298         }
4299
4300         /**
4301          * Get the number of revisions between the given revision.
4302          * Used for diffs and other things that really need it.
4303          *
4304          * @param int|Revision $old Old revision or rev ID (first before range)
4305          * @param int|Revision $new New revision or rev ID (first after range)
4306          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4307          * @return int Number of revisions between these revisions.
4308          */
4309         public function countRevisionsBetween( $old, $new, $max = null ) {
4310                 if ( !( $old instanceof Revision ) ) {
4311                         $old = Revision::newFromTitle( $this, (int)$old );
4312                 }
4313                 if ( !( $new instanceof Revision ) ) {
4314                         $new = Revision::newFromTitle( $this, (int)$new );
4315                 }
4316                 if ( !$old || !$new ) {
4317                         return 0; // nothing to compare
4318                 }
4319                 $dbr = wfGetDB( DB_SLAVE );
4320                 $conds = array(
4321                         'rev_page' => $this->getArticleID(),
4322                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4323                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4324                 );
4325                 if ( $max !== null ) {
4326                         $res = $dbr->select( 'revision', '1',
4327                                 $conds,
4328                                 __METHOD__,
4329                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4330                         );
4331                         return $res->numRows();
4332                 } else {
4333                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4334                 }
4335         }
4336
4337         /**
4338          * Get the authors between the given revisions or revision IDs.
4339          * Used for diffs and other things that really need it.
4340          *
4341          * @since 1.23
4342          *
4343          * @param int|Revision $old Old revision or rev ID (first before range by default)
4344          * @param int|Revision $new New revision or rev ID (first after range by default)
4345          * @param int $limit Maximum number of authors
4346          * @param string|array $options (Optional): Single option, or an array of options:
4347          *     'include_old' Include $old in the range; $new is excluded.
4348          *     'include_new' Include $new in the range; $old is excluded.
4349          *     'include_both' Include both $old and $new in the range.
4350          *     Unknown option values are ignored.
4351          * @return array|null Names of revision authors in the range; null if not both revisions exist
4352          */
4353         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4354                 if ( !( $old instanceof Revision ) ) {
4355                         $old = Revision::newFromTitle( $this, (int)$old );
4356                 }
4357                 if ( !( $new instanceof Revision ) ) {
4358                         $new = Revision::newFromTitle( $this, (int)$new );
4359                 }
4360                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4361                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4362                 // in the sanity check below?
4363                 if ( !$old || !$new ) {
4364                         return null; // nothing to compare
4365                 }
4366                 $authors = array();
4367                 $old_cmp = '>';
4368                 $new_cmp = '<';
4369                 $options = (array)$options;
4370                 if ( in_array( 'include_old', $options ) ) {
4371                         $old_cmp = '>=';
4372                 }
4373                 if ( in_array( 'include_new', $options ) ) {
4374                         $new_cmp = '<=';
4375                 }
4376                 if ( in_array( 'include_both', $options ) ) {
4377                         $old_cmp = '>=';
4378                         $new_cmp = '<=';
4379                 }
4380                 // No DB query needed if $old and $new are the same or successive revisions:
4381                 if ( $old->getId() === $new->getId() ) {
4382                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4383                 } elseif ( $old->getId() === $new->getParentId() ) {
4384                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4385                                 $authors[] = $old->getRawUserText();
4386                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4387                                         $authors[] = $new->getRawUserText();
4388                                 }
4389                         } elseif ( $old_cmp === '>=' ) {
4390                                 $authors[] = $old->getRawUserText();
4391                         } elseif ( $new_cmp === '<=' ) {
4392                                 $authors[] = $new->getRawUserText();
4393                         }
4394                         return $authors;
4395                 }
4396                 $dbr = wfGetDB( DB_SLAVE );
4397                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4398                         array(
4399                                 'rev_page' => $this->getArticleID(),
4400                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4401                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4402                         ), __METHOD__,
4403                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4404                 );
4405                 foreach ( $res as $row ) {
4406                         $authors[] = $row->rev_user_text;
4407                 }
4408                 return $authors;
4409         }
4410
4411         /**
4412          * Get the number of authors between the given revisions or revision IDs.
4413          * Used for diffs and other things that really need it.
4414          *
4415          * @param int|Revision $old Old revision or rev ID (first before range by default)
4416          * @param int|Revision $new New revision or rev ID (first after range by default)
4417          * @param int $limit Maximum number of authors
4418          * @param string|array $options (Optional): Single option, or an array of options:
4419          *     'include_old' Include $old in the range; $new is excluded.
4420          *     'include_new' Include $new in the range; $old is excluded.
4421          *     'include_both' Include both $old and $new in the range.
4422          *     Unknown option values are ignored.
4423          * @return int Number of revision authors in the range; zero if not both revisions exist
4424          */
4425         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4426                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4427                 return $authors ? count( $authors ) : 0;
4428         }
4429
4430         /**
4431          * Compare with another title.
4432          *
4433          * @param Title $title
4434          * @return bool
4435          */
4436         public function equals( Title $title ) {
4437                 // Note: === is necessary for proper matching of number-like titles.
4438                 return $this->getInterwiki() === $title->getInterwiki()
4439                         && $this->getNamespace() == $title->getNamespace()
4440                         && $this->getDBkey() === $title->getDBkey();
4441         }
4442
4443         /**
4444          * Check if this title is a subpage of another title
4445          *
4446          * @param Title $title
4447          * @return bool
4448          */
4449         public function isSubpageOf( Title $title ) {
4450                 return $this->getInterwiki() === $title->getInterwiki()
4451                         && $this->getNamespace() == $title->getNamespace()
4452                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4453         }
4454
4455         /**
4456          * Check if page exists.  For historical reasons, this function simply
4457          * checks for the existence of the title in the page table, and will
4458          * thus return false for interwiki links, special pages and the like.
4459          * If you want to know if a title can be meaningfully viewed, you should
4460          * probably call the isKnown() method instead.
4461          *
4462          * @return bool
4463          */
4464         public function exists() {
4465                 return $this->getArticleID() != 0;
4466         }
4467
4468         /**
4469          * Should links to this title be shown as potentially viewable (i.e. as
4470          * "bluelinks"), even if there's no record by this title in the page
4471          * table?
4472          *
4473          * This function is semi-deprecated for public use, as well as somewhat
4474          * misleadingly named.  You probably just want to call isKnown(), which
4475          * calls this function internally.
4476          *
4477          * (ISSUE: Most of these checks are cheap, but the file existence check
4478          * can potentially be quite expensive.  Including it here fixes a lot of
4479          * existing code, but we might want to add an optional parameter to skip
4480          * it and any other expensive checks.)
4481          *
4482          * @return bool
4483          */
4484         public function isAlwaysKnown() {
4485                 $isKnown = null;
4486
4487                 /**
4488                  * Allows overriding default behavior for determining if a page exists.
4489                  * If $isKnown is kept as null, regular checks happen. If it's
4490                  * a boolean, this value is returned by the isKnown method.
4491                  *
4492                  * @since 1.20
4493                  *
4494                  * @param Title $title
4495                  * @param bool|null $isKnown
4496                  */
4497                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4498
4499                 if ( !is_null( $isKnown ) ) {
4500                         return $isKnown;
4501                 }
4502
4503                 if ( $this->isExternal() ) {
4504                         return true;  // any interwiki link might be viewable, for all we know
4505                 }
4506
4507                 switch ( $this->mNamespace ) {
4508                         case NS_MEDIA:
4509                         case NS_FILE:
4510                                 // file exists, possibly in a foreign repo
4511                                 return (bool)wfFindFile( $this );
4512                         case NS_SPECIAL:
4513                                 // valid special page
4514                                 return SpecialPageFactory::exists( $this->getDBkey() );
4515                         case NS_MAIN:
4516                                 // selflink, possibly with fragment
4517                                 return $this->mDbkeyform == '';
4518                         case NS_MEDIAWIKI:
4519                                 // known system message
4520                                 return $this->hasSourceText() !== false;
4521                         default:
4522                                 return false;
4523                 }
4524         }
4525
4526         /**
4527          * Does this title refer to a page that can (or might) be meaningfully
4528          * viewed?  In particular, this function may be used to determine if
4529          * links to the title should be rendered as "bluelinks" (as opposed to
4530          * "redlinks" to non-existent pages).
4531          * Adding something else to this function will cause inconsistency
4532          * since LinkHolderArray calls isAlwaysKnown() and does its own
4533          * page existence check.
4534          *
4535          * @return bool
4536          */
4537         public function isKnown() {
4538                 return $this->isAlwaysKnown() || $this->exists();
4539         }
4540
4541         /**
4542          * Does this page have source text?
4543          *
4544          * @return bool
4545          */
4546         public function hasSourceText() {
4547                 if ( $this->exists() ) {
4548                         return true;
4549                 }
4550
4551                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4552                         // If the page doesn't exist but is a known system message, default
4553                         // message content will be displayed, same for language subpages-
4554                         // Use always content language to avoid loading hundreds of languages
4555                         // to get the link color.
4556                         global $wgContLang;
4557                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4558                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4559                         return $message->exists();
4560                 }
4561
4562                 return false;
4563         }
4564
4565         /**
4566          * Get the default message text or false if the message doesn't exist
4567          *
4568          * @return string|bool
4569          */
4570         public function getDefaultMessageText() {
4571                 global $wgContLang;
4572
4573                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4574                         return false;
4575                 }
4576
4577                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4578                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4579
4580                 if ( $message->exists() ) {
4581                         return $message->plain();
4582                 } else {
4583                         return false;
4584                 }
4585         }
4586
4587         /**
4588          * Updates page_touched for this page; called from LinksUpdate.php
4589          *
4590          * @return bool True if the update succeeded
4591          */
4592         public function invalidateCache() {
4593                 if ( wfReadOnly() ) {
4594                         return false;
4595                 }
4596
4597                 $method = __METHOD__;
4598                 $dbw = wfGetDB( DB_MASTER );
4599                 $conds = $this->pageCond();
4600                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4601                         $dbw->update(
4602                                 'page',
4603                                 array( 'page_touched' => $dbw->timestamp() ),
4604                                 $conds,
4605                                 $method
4606                         );
4607                 } );
4608
4609                 return true;
4610         }
4611
4612         /**
4613          * Update page_touched timestamps and send squid purge messages for
4614          * pages linking to this title. May be sent to the job queue depending
4615          * on the number of links. Typically called on create and delete.
4616          */
4617         public function touchLinks() {
4618                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4619                 $u->doUpdate();
4620
4621                 if ( $this->getNamespace() == NS_CATEGORY ) {
4622                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4623                         $u->doUpdate();
4624                 }
4625         }
4626
4627         /**
4628          * Get the last touched timestamp
4629          *
4630          * @param DatabaseBase $db Optional db
4631          * @return string Last-touched timestamp
4632          */
4633         public function getTouched( $db = null ) {
4634                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4635                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4636                 return $touched;
4637         }
4638
4639         /**
4640          * Get the timestamp when this page was updated since the user last saw it.
4641          *
4642          * @param User $user
4643          * @return string|null
4644          */
4645         public function getNotificationTimestamp( $user = null ) {
4646                 global $wgUser, $wgShowUpdatedMarker;
4647                 // Assume current user if none given
4648                 if ( !$user ) {
4649                         $user = $wgUser;
4650                 }
4651                 // Check cache first
4652                 $uid = $user->getId();
4653                 // avoid isset here, as it'll return false for null entries
4654                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4655                         return $this->mNotificationTimestamp[$uid];
4656                 }
4657                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4658                         $this->mNotificationTimestamp[$uid] = false;
4659                         return $this->mNotificationTimestamp[$uid];
4660                 }
4661                 // Don't cache too much!
4662                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4663                         $this->mNotificationTimestamp = array();
4664                 }
4665                 $dbr = wfGetDB( DB_SLAVE );
4666                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4667                         'wl_notificationtimestamp',
4668                         array(
4669                                 'wl_user' => $user->getId(),
4670                                 'wl_namespace' => $this->getNamespace(),
4671                                 'wl_title' => $this->getDBkey(),
4672                         ),
4673                         __METHOD__
4674                 );
4675                 return $this->mNotificationTimestamp[$uid];
4676         }
4677
4678         /**
4679          * Generate strings used for xml 'id' names in monobook tabs
4680          *
4681          * @param string $prepend Defaults to 'nstab-'
4682          * @return string XML 'id' name
4683          */
4684         public function getNamespaceKey( $prepend = 'nstab-' ) {
4685                 global $wgContLang;
4686                 // Gets the subject namespace if this title
4687                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4688                 // Checks if canonical namespace name exists for namespace
4689                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4690                         // Uses canonical namespace name
4691                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4692                 } else {
4693                         // Uses text of namespace
4694                         $namespaceKey = $this->getSubjectNsText();
4695                 }
4696                 // Makes namespace key lowercase
4697                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4698                 // Uses main
4699                 if ( $namespaceKey == '' ) {
4700                         $namespaceKey = 'main';
4701                 }
4702                 // Changes file to image for backwards compatibility
4703                 if ( $namespaceKey == 'file' ) {
4704                         $namespaceKey = 'image';
4705                 }
4706                 return $prepend . $namespaceKey;
4707         }
4708
4709         /**
4710          * Get all extant redirects to this Title
4711          *
4712          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4713          * @return Title[] Array of Title redirects to this title
4714          */
4715         public function getRedirectsHere( $ns = null ) {
4716                 $redirs = array();
4717
4718                 $dbr = wfGetDB( DB_SLAVE );
4719                 $where = array(
4720                         'rd_namespace' => $this->getNamespace(),
4721                         'rd_title' => $this->getDBkey(),
4722                         'rd_from = page_id'
4723                 );
4724                 if ( $this->isExternal() ) {
4725                         $where['rd_interwiki'] = $this->getInterwiki();
4726                 } else {
4727                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4728                 }
4729                 if ( !is_null( $ns ) ) {
4730                         $where['page_namespace'] = $ns;
4731                 }
4732
4733                 $res = $dbr->select(
4734                         array( 'redirect', 'page' ),
4735                         array( 'page_namespace', 'page_title' ),
4736                         $where,
4737                         __METHOD__
4738                 );
4739
4740                 foreach ( $res as $row ) {
4741                         $redirs[] = self::newFromRow( $row );
4742                 }
4743                 return $redirs;
4744         }
4745
4746         /**
4747          * Check if this Title is a valid redirect target
4748          *
4749          * @return bool
4750          */
4751         public function isValidRedirectTarget() {
4752                 global $wgInvalidRedirectTargets;
4753
4754                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4755                 if ( $this->isSpecial( 'Userlogout' ) ) {
4756                         return false;
4757                 }
4758
4759                 foreach ( $wgInvalidRedirectTargets as $target ) {
4760                         if ( $this->isSpecial( $target ) ) {
4761                                 return false;
4762                         }
4763                 }
4764
4765                 return true;
4766         }
4767
4768         /**
4769          * Get a backlink cache object
4770          *
4771          * @return BacklinkCache
4772          */
4773         public function getBacklinkCache() {
4774                 return BacklinkCache::get( $this );
4775         }
4776
4777         /**
4778          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4779          *
4780          * @return bool
4781          */
4782         public function canUseNoindex() {
4783                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4784
4785                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4786                         ? $wgContentNamespaces
4787                         : $wgExemptFromUserRobotsControl;
4788
4789                 return !in_array( $this->mNamespace, $bannedNamespaces );
4790
4791         }
4792
4793         /**
4794          * Returns the raw sort key to be used for categories, with the specified
4795          * prefix.  This will be fed to Collation::getSortKey() to get a
4796          * binary sortkey that can be used for actual sorting.
4797          *
4798          * @param string $prefix The prefix to be used, specified using
4799          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4800          *   prefix.
4801          * @return string
4802          */
4803         public function getCategorySortkey( $prefix = '' ) {
4804                 $unprefixed = $this->getText();
4805
4806                 // Anything that uses this hook should only depend
4807                 // on the Title object passed in, and should probably
4808                 // tell the users to run updateCollations.php --force
4809                 // in order to re-sort existing category relations.
4810                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4811                 if ( $prefix !== '' ) {
4812                         # Separate with a line feed, so the unprefixed part is only used as
4813                         # a tiebreaker when two pages have the exact same prefix.
4814                         # In UCA, tab is the only character that can sort above LF
4815                         # so we strip both of them from the original prefix.
4816                         $prefix = strtr( $prefix, "\n\t", '  ' );
4817                         return "$prefix\n$unprefixed";
4818                 }
4819                 return $unprefixed;
4820         }
4821
4822         /**
4823          * Get the language in which the content of this page is written in
4824          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4825          * e.g. $wgLang (such as special pages, which are in the user language).
4826          *
4827          * @since 1.18
4828          * @return Language
4829          */
4830         public function getPageLanguage() {
4831                 global $wgLang, $wgLanguageCode;
4832                 wfProfileIn( __METHOD__ );
4833                 if ( $this->isSpecialPage() ) {
4834                         // special pages are in the user language
4835                         wfProfileOut( __METHOD__ );
4836                         return $wgLang;
4837                 }
4838
4839                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4840                         // Note that this may depend on user settings, so the cache should be only per-request.
4841                         // NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4842                         // Checking $wgLanguageCode hasn't changed for the benefit of unit tests.
4843                         $contentHandler = ContentHandler::getForTitle( $this );
4844                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4845                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4846                 } else {
4847                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4848                 }
4849                 wfProfileOut( __METHOD__ );
4850                 return $langObj;
4851         }
4852
4853         /**
4854          * Get the language in which the content of this page is written when
4855          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4856          * e.g. $wgLang (such as special pages, which are in the user language).
4857          *
4858          * @since 1.20
4859          * @return Language
4860          */
4861         public function getPageViewLanguage() {
4862                 global $wgLang;
4863
4864                 if ( $this->isSpecialPage() ) {
4865                         // If the user chooses a variant, the content is actually
4866                         // in a language whose code is the variant code.
4867                         $variant = $wgLang->getPreferredVariant();
4868                         if ( $wgLang->getCode() !== $variant ) {
4869                                 return Language::factory( $variant );
4870                         }
4871
4872                         return $wgLang;
4873                 }
4874
4875                 //NOTE: can't be cached persistently, depends on user settings
4876                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4877                 $contentHandler = ContentHandler::getForTitle( $this );
4878                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4879                 return $pageLang;
4880         }
4881
4882         /**
4883          * Get a list of rendered edit notices for this page.
4884          *
4885          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4886          * they will already be wrapped in paragraphs.
4887          *
4888          * @since 1.21
4889          * @param int $oldid Revision ID that's being edited
4890          * @return array
4891          */
4892         public function getEditNotices( $oldid = 0 ) {
4893                 $notices = array();
4894
4895                 # Optional notices on a per-namespace and per-page basis
4896                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4897                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4898                 if ( $editnotice_ns_message->exists() ) {
4899                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4900                 }
4901                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4902                         $parts = explode( '/', $this->getDBkey() );
4903                         $editnotice_base = $editnotice_ns;
4904                         while ( count( $parts ) > 0 ) {
4905                                 $editnotice_base .= '-' . array_shift( $parts );
4906                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4907                                 if ( $editnotice_base_msg->exists() ) {
4908                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4909                                 }
4910                         }
4911                 } else {
4912                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4913                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4914                         $editnoticeMsg = wfMessage( $editnoticeText );
4915                         if ( $editnoticeMsg->exists() ) {
4916                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4917                         }
4918                 }
4919
4920                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4921                 return $notices;
4922         }
4923 }