includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  83                                                                           # Zero except in {{transclusion}} tags
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mHasSubpage;                 // /< Whether a page has any subpages
  89         // @}
  90
  91
  92         /**
  93          * Constructor
  94          */
  95         /*protected*/ function __construct() { }
  96
  97         /**
  98          * Create a new Title from a prefixed DB key
  99          *
 100          * @param $key String the database key, which has underscores
 101          *      instead of spaces, possibly including namespace and
 102          *      interwiki prefixes
 103          * @return Title, or NULL on an error
 104          */
 105         public static function newFromDBkey( $key ) {
 106                 $t = new Title();
 107                 $t->mDbkeyform = $key;
 108                 if ( $t->secureAndSplit() ) {
 109                         return $t;
 110                 } else {
 111                         return null;
 112                 }
 113         }
 114
 115         /**
 116          * Create a new Title from text, such as what one would find in a link. De-
 117          * codes any HTML entities in the text.
 118          *
 119          * @param $text String the link text; spaces, prefixes, and an
 120          *   initial ':' indicating the main namespace are accepted.
 121          * @param $defaultNamespace Int the namespace to use if none is speci-
 122          *   fied by a prefix.  If you want to force a specific namespace even if
 123          *   $text might begin with a namespace prefix, use makeTitle() or
 124          *   makeTitleSafe().
 125          * @throws MWException
 126          * @return Title|null - Title or null on an error.
 127          */
 128         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 129                 if ( is_object( $text ) ) {
 130                         throw new MWException( 'Title::newFromText given an object' );
 131                 }
 132
 133                 /**
 134                  * Wiki pages often contain multiple links to the same page.
 135                  * Title normalization and parsing can become expensive on
 136                  * pages with many links, so we can save a little time by
 137                  * caching them.
 138                  *
 139                  * In theory these are value objects and won't get changed...
 140                  */
 141                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 142                         return Title::$titleCache[$text];
 143                 }
 144
 145                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 146                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 147
 148                 $t = new Title();
 149                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 150                 $t->mDefaultNamespace = $defaultNamespace;
 151
 152                 static $cachedcount = 0 ;
 153                 if ( $t->secureAndSplit() ) {
 154                         if ( $defaultNamespace == NS_MAIN ) {
 155                                 if ( $cachedcount >= self::CACHE_MAX ) {
 156                                         # Avoid memory leaks on mass operations...
 157                                         Title::$titleCache = array();
 158                                         $cachedcount = 0;
 159                                 }
 160                                 $cachedcount++;
 161                                 Title::$titleCache[$text] =& $t;
 162                         }
 163                         return $t;
 164                 } else {
 165                         $ret = null;
 166                         return $ret;
 167                 }
 168         }
 169
 170         /**
 171          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 172          *
 173          * Example of wrong and broken code:
 174          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 175          *
 176          * Example of right code:
 177          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 178          *
 179          * Create a new Title from URL-encoded text. Ensures that
 180          * the given title's length does not exceed the maximum.
 181          *
 182          * @param $url String the title, as might be taken from a URL
 183          * @return Title the new object, or NULL on an error
 184          */
 185         public static function newFromURL( $url ) {
 186                 $t = new Title();
 187
 188                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 189                 # but some URLs used it as a space replacement and they still come
 190                 # from some external search tools.
 191                 if ( strpos( self::legalChars(), '+' ) === false ) {
 192                         $url = str_replace( '+', ' ', $url );
 193                 }
 194
 195                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 196                 if ( $t->secureAndSplit() ) {
 197                         return $t;
 198                 } else {
 199                         return null;
 200                 }
 201         }
 202
 203         /**
 204          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 205          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 206          *
 207          * @return array
 208          */
 209         protected static function getSelectFields() {
 210                 global $wgContentHandlerUseDB;
 211
 212                 $fields = array(
 213                         'page_namespace', 'page_title', 'page_id',
 214                         'page_len', 'page_is_redirect', 'page_latest',
 215                 );
 216
 217                 if ( $wgContentHandlerUseDB ) {
 218                         $fields[] = 'page_content_model';
 219                 }
 220
 221                 return $fields;
 222         }
 223
 224         /**
 225          * Create a new Title from an article ID
 226          *
 227          * @param $id Int the page_id corresponding to the Title to create
 228          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 229          * @return Title the new object, or NULL on an error
 230          */
 231         public static function newFromID( $id, $flags = 0 ) {
 232                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 233                 $row = $db->selectRow(
 234                         'page',
 235                         self::getSelectFields(),
 236                         array( 'page_id' => $id ),
 237                         __METHOD__
 238                 );
 239                 if ( $row !== false ) {
 240                         $title = Title::newFromRow( $row );
 241                 } else {
 242                         $title = null;
 243                 }
 244                 return $title;
 245         }
 246
 247         /**
 248          * Make an array of titles from an array of IDs
 249          *
 250          * @param $ids Array of Int Array of IDs
 251          * @return Array of Titles
 252          */
 253         public static function newFromIDs( $ids ) {
 254                 if ( !count( $ids ) ) {
 255                         return array();
 256                 }
 257                 $dbr = wfGetDB( DB_SLAVE );
 258
 259                 $res = $dbr->select(
 260                         'page',
 261                         self::getSelectFields(),
 262                         array( 'page_id' => $ids ),
 263                         __METHOD__
 264                 );
 265
 266                 $titles = array();
 267                 foreach ( $res as $row ) {
 268                         $titles[] = Title::newFromRow( $row );
 269                 }
 270                 return $titles;
 271         }
 272
 273         /**
 274          * Make a Title object from a DB row
 275          *
 276          * @param $row Object database row (needs at least page_title,page_namespace)
 277          * @return Title corresponding Title
 278          */
 279         public static function newFromRow( $row ) {
 280                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 281                 $t->loadFromRow( $row );
 282                 return $t;
 283         }
 284
 285         /**
 286          * Load Title object fields from a DB row.
 287          * If false is given, the title will be treated as non-existing.
 288          *
 289          * @param $row Object|bool database row
 290          */
 291         public function loadFromRow( $row ) {
 292                 if ( $row ) { // page found
 293                         if ( isset( $row->page_id ) )
 294                                 $this->mArticleID = (int)$row->page_id;
 295                         if ( isset( $row->page_len ) )
 296                                 $this->mLength = (int)$row->page_len;
 297                         if ( isset( $row->page_is_redirect ) )
 298                                 $this->mRedirect = (bool)$row->page_is_redirect;
 299                         if ( isset( $row->page_latest ) )
 300                                 $this->mLatestID = (int)$row->page_latest;
 301                         if ( isset( $row->page_content_model ) )
 302                                 $this->mContentModel = strval( $row->page_content_model );
 303                         else
 304                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 305                 } else { // page not found
 306                         $this->mArticleID = 0;
 307                         $this->mLength = 0;
 308                         $this->mRedirect = false;
 309                         $this->mLatestID = 0;
 310                         $this->mContentModel = false; # initialized lazily in getContentModel()
 311                 }
 312         }
 313
 314         /**
 315          * Create a new Title from a namespace index and a DB key.
 316          * It's assumed that $ns and $title are *valid*, for instance when
 317          * they came directly from the database or a special page name.
 318          * For convenience, spaces are converted to underscores so that
 319          * eg user_text fields can be used directly.
 320          *
 321          * @param $ns Int the namespace of the article
 322          * @param $title String the unprefixed database key form
 323          * @param $fragment String the link fragment (after the "#")
 324          * @param $interwiki String the interwiki prefix
 325          * @return Title the new object
 326          */
 327         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 328                 $t = new Title();
 329                 $t->mInterwiki = $interwiki;
 330                 $t->mFragment = $fragment;
 331                 $t->mNamespace = $ns = intval( $ns );
 332                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 333                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 334                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 335                 $t->mTextform = str_replace( '_', ' ', $title );
 336                 $t->mContentModel = false; # initialized lazily in getContentModel()
 337                 return $t;
 338         }
 339
 340         /**
 341          * Create a new Title from a namespace index and a DB key.
 342          * The parameters will be checked for validity, which is a bit slower
 343          * than makeTitle() but safer for user-provided data.
 344          *
 345          * @param $ns Int the namespace of the article
 346          * @param $title String database key form
 347          * @param $fragment String the link fragment (after the "#")
 348          * @param $interwiki String interwiki prefix
 349          * @return Title the new object, or NULL on an error
 350          */
 351         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 352                 if ( !MWNamespace::exists( $ns ) ) {
 353                         return null;
 354                 }
 355
 356                 $t = new Title();
 357                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 358                 if ( $t->secureAndSplit() ) {
 359                         return $t;
 360                 } else {
 361                         return null;
 362                 }
 363         }
 364
 365         /**
 366          * Create a new Title for the Main Page
 367          *
 368          * @return Title the new object
 369          */
 370         public static function newMainPage() {
 371                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 372                 // Don't give fatal errors if the message is broken
 373                 if ( !$title ) {
 374                         $title = Title::newFromText( 'Main Page' );
 375                 }
 376                 return $title;
 377         }
 378
 379         /**
 380          * Extract a redirect destination from a string and return the
 381          * Title, or null if the text doesn't contain a valid redirect
 382          * This will only return the very next target, useful for
 383          * the redirect table and other checks that don't need full recursion
 384          *
 385          * @param $text String: Text with possible redirect
 386          * @return Title: The corresponding Title
 387          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 388          */
 389         public static function newFromRedirect( $text ) {
 390                 ContentHandler::deprecated( __METHOD__, '1.21' );
 391
 392                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 393                 return $content->getRedirectTarget();
 394         }
 395
 396         /**
 397          * Extract a redirect destination from a string and return the
 398          * Title, or null if the text doesn't contain a valid redirect
 399          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 400          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 401          *
 402          * @param $text String Text with possible redirect
 403          * @return Title
 404          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 405          */
 406         public static function newFromRedirectRecurse( $text ) {
 407                 ContentHandler::deprecated( __METHOD__, '1.21' );
 408
 409                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 410                 return $content->getUltimateRedirectTarget();
 411         }
 412
 413         /**
 414          * Extract a redirect destination from a string and return an
 415          * array of Titles, or null if the text doesn't contain a valid redirect
 416          * The last element in the array is the final destination after all redirects
 417          * have been resolved (up to $wgMaxRedirects times)
 418          *
 419          * @param $text String Text with possible redirect
 420          * @return Array of Titles, with the destination last
 421          * @deprecated since 1.21, use Content::getRedirectChain instead.
 422          */
 423         public static function newFromRedirectArray( $text ) {
 424                 ContentHandler::deprecated( __METHOD__, '1.21' );
 425
 426                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 427                 return $content->getRedirectChain();
 428         }
 429
 430         /**
 431          * Get the prefixed DB key associated with an ID
 432          *
 433          * @param $id Int the page_id of the article
 434          * @return Title an object representing the article, or NULL if no such article was found
 435          */
 436         public static function nameOf( $id ) {
 437                 $dbr = wfGetDB( DB_SLAVE );
 438
 439                 $s = $dbr->selectRow(
 440                         'page',
 441                         array( 'page_namespace', 'page_title' ),
 442                         array( 'page_id' => $id ),
 443                         __METHOD__
 444                 );
 445                 if ( $s === false ) {
 446                         return null;
 447                 }
 448
 449                 $n = self::makeName( $s->page_namespace, $s->page_title );
 450                 return $n;
 451         }
 452
 453         /**
 454          * Get a regex character class describing the legal characters in a link
 455          *
 456          * @return String the list of characters, not delimited
 457          */
 458         public static function legalChars() {
 459                 global $wgLegalTitleChars;
 460                 return $wgLegalTitleChars;
 461         }
 462
 463         /**
 464          * Returns a simple regex that will match on characters and sequences invalid in titles.
 465          * Note that this doesn't pick up many things that could be wrong with titles, but that
 466          * replacing this regex with something valid will make many titles valid.
 467          *
 468          * @return String regex string
 469          */
 470         static function getTitleInvalidRegex() {
 471                 static $rxTc = false;
 472                 if ( !$rxTc ) {
 473                         # Matching titles will be held as illegal.
 474                         $rxTc = '/' .
 475                                 # Any character not allowed is forbidden...
 476                                 '[^' . self::legalChars() . ']' .
 477                                 # URL percent encoding sequences interfere with the ability
 478                                 # to round-trip titles -- you can't link to them consistently.
 479                                 '|%[0-9A-Fa-f]{2}' .
 480                                 # XML/HTML character references produce similar issues.
 481                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 482                                 '|&#[0-9]+;' .
 483                                 '|&#x[0-9A-Fa-f]+;' .
 484                                 '/S';
 485                 }
 486
 487                 return $rxTc;
 488         }
 489
 490         /**
 491          * Get a string representation of a title suitable for
 492          * including in a search index
 493          *
 494          * @param $ns Int a namespace index
 495          * @param $title String text-form main part
 496          * @return String a stripped-down title string ready for the search index
 497          */
 498         public static function indexTitle( $ns, $title ) {
 499                 global $wgContLang;
 500
 501                 $lc = SearchEngine::legalSearchChars() . '&#;';
 502                 $t = $wgContLang->normalizeForSearch( $title );
 503                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 504                 $t = $wgContLang->lc( $t );
 505
 506                 # Handle 's, s'
 507                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 508                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 509
 510                 $t = preg_replace( "/\\s+/", ' ', $t );
 511
 512                 if ( $ns == NS_FILE ) {
 513                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 514                 }
 515                 return trim( $t );
 516         }
 517
 518         /**
 519          * Make a prefixed DB key from a DB key and a namespace index
 520          *
 521          * @param $ns Int numerical representation of the namespace
 522          * @param $title String the DB key form the title
 523          * @param $fragment String The link fragment (after the "#")
 524          * @param $interwiki String The interwiki prefix
 525          * @return String the prefixed form of the title
 526          */
 527         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 528                 global $wgContLang;
 529
 530                 $namespace = $wgContLang->getNsText( $ns );
 531                 $name = $namespace == '' ? $title : "$namespace:$title";
 532                 if ( strval( $interwiki ) != '' ) {
 533                         $name = "$interwiki:$name";
 534                 }
 535                 if ( strval( $fragment ) != '' ) {
 536                         $name .= '#' . $fragment;
 537                 }
 538                 return $name;
 539         }
 540
 541         /**
 542          * Escape a text fragment, say from a link, for a URL
 543          *
 544          * @param $fragment string containing a URL or link fragment (after the "#")
 545          * @return String: escaped string
 546          */
 547         static function escapeFragmentForURL( $fragment ) {
 548                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 549                 # fragments appear not to work in IE (at least up to 7) or in at least
 550                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 551                 # to care if they aren't encoded.
 552                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 553         }
 554
 555         /**
 556          * Callback for usort() to do title sorts by (namespace, title)
 557          *
 558          * @param $a Title
 559          * @param $b Title
 560          *
 561          * @return Integer: result of string comparison, or namespace comparison
 562          */
 563         public static function compare( $a, $b ) {
 564                 if ( $a->getNamespace() == $b->getNamespace() ) {
 565                         return strcmp( $a->getText(), $b->getText() );
 566                 } else {
 567                         return $a->getNamespace() - $b->getNamespace();
 568                 }
 569         }
 570
 571         /**
 572          * Determine whether the object refers to a page within
 573          * this project.
 574          *
 575          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 576          */
 577         public function isLocal() {
 578                 if ( $this->mInterwiki != '' ) {
 579                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 580                 } else {
 581                         return true;
 582                 }
 583         }
 584
 585         /**
 586          * Is this Title interwiki?
 587          *
 588          * @return Bool
 589          */
 590         public function isExternal() {
 591                 return ( $this->mInterwiki != '' );
 592         }
 593
 594         /**
 595          * Get the interwiki prefix (or null string)
 596          *
 597          * @return String Interwiki prefix
 598          */
 599         public function getInterwiki() {
 600                 return $this->mInterwiki;
 601         }
 602
 603         /**
 604          * Determine whether the object refers to a page within
 605          * this project and is transcludable.
 606          *
 607          * @return Bool TRUE if this is transcludable
 608          */
 609         public function isTrans() {
 610                 if ( $this->mInterwiki == '' ) {
 611                         return false;
 612                 }
 613
 614                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 615         }
 616
 617         /**
 618          * Returns the DB name of the distant wiki which owns the object.
 619          *
 620          * @return String the DB name
 621          */
 622         public function getTransWikiID() {
 623                 if ( $this->mInterwiki == '' ) {
 624                         return false;
 625                 }
 626
 627                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 628         }
 629
 630         /**
 631          * Get the text form (spaces not underscores) of the main part
 632          *
 633          * @return String Main part of the title
 634          */
 635         public function getText() {
 636                 return $this->mTextform;
 637         }
 638
 639         /**
 640          * Get the URL-encoded form of the main part
 641          *
 642          * @return String Main part of the title, URL-encoded
 643          */
 644         public function getPartialURL() {
 645                 return $this->mUrlform;
 646         }
 647
 648         /**
 649          * Get the main part with underscores
 650          *
 651          * @return String: Main part of the title, with underscores
 652          */
 653         public function getDBkey() {
 654                 return $this->mDbkeyform;
 655         }
 656
 657         /**
 658          * Get the DB key with the initial letter case as specified by the user
 659          *
 660          * @return String DB key
 661          */
 662         function getUserCaseDBKey() {
 663                 return $this->mUserCaseDBKey;
 664         }
 665
 666         /**
 667          * Get the namespace index, i.e. one of the NS_xxxx constants.
 668          *
 669          * @return Integer: Namespace index
 670          */
 671         public function getNamespace() {
 672                 return $this->mNamespace;
 673         }
 674
 675         /**
 676          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 677          *
 678          * @throws MWException
 679          * @return String: Content model id
 680          */
 681         public function getContentModel() {
 682                 if ( !$this->mContentModel ) {
 683                         $linkCache = LinkCache::singleton();
 684                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 685                 }
 686
 687                 if ( !$this->mContentModel ) {
 688                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 689                 }
 690
 691                 if( !$this->mContentModel ) {
 692                         throw new MWException( "failed to determin content model!" );
 693                 }
 694
 695                 return $this->mContentModel;
 696         }
 697
 698         /**
 699          * Convenience method for checking a title's content model name
 700          *
 701          * @param String $id The content model ID (use the CONTENT_MODEL_XXX constants).
 702          * @return Boolean true if $this->getContentModel() == $id
 703          */
 704         public function hasContentModel( $id ) {
 705                 return $this->getContentModel() == $id;
 706         }
 707
 708         /**
 709          * Get the namespace text
 710          *
 711          * @return String: Namespace text
 712          */
 713         public function getNsText() {
 714                 global $wgContLang;
 715
 716                 if ( $this->mInterwiki != '' ) {
 717                         // This probably shouldn't even happen. ohh man, oh yuck.
 718                         // But for interwiki transclusion it sometimes does.
 719                         // Shit. Shit shit shit.
 720                         //
 721                         // Use the canonical namespaces if possible to try to
 722                         // resolve a foreign namespace.
 723                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 724                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 725                         }
 726                 }
 727
 728                 if ( $wgContLang->needsGenderDistinction() &&
 729                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 730                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 731                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 732                 }
 733
 734                 return $wgContLang->getNsText( $this->mNamespace );
 735         }
 736
 737         /**
 738          * Get the namespace text of the subject (rather than talk) page
 739          *
 740          * @return String Namespace text
 741          */
 742         public function getSubjectNsText() {
 743                 global $wgContLang;
 744                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 745         }
 746
 747         /**
 748          * Get the namespace text of the talk page
 749          *
 750          * @return String Namespace text
 751          */
 752         public function getTalkNsText() {
 753                 global $wgContLang;
 754                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 755         }
 756
 757         /**
 758          * Could this title have a corresponding talk page?
 759          *
 760          * @return Bool TRUE or FALSE
 761          */
 762         public function canTalk() {
 763                 return( MWNamespace::canTalk( $this->mNamespace ) );
 764         }
 765
 766         /**
 767          * Is this in a namespace that allows actual pages?
 768          *
 769          * @return Bool
 770          * @internal note -- uses hardcoded namespace index instead of constants
 771          */
 772         public function canExist() {
 773                 return $this->mNamespace >= NS_MAIN;
 774         }
 775
 776         /**
 777          * Can this title be added to a user's watchlist?
 778          *
 779          * @return Bool TRUE or FALSE
 780          */
 781         public function isWatchable() {
 782                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 783         }
 784
 785         /**
 786          * Returns true if this is a special page.
 787          *
 788          * @return boolean
 789          */
 790         public function isSpecialPage() {
 791                 return $this->getNamespace() == NS_SPECIAL;
 792         }
 793
 794         /**
 795          * Returns true if this title resolves to the named special page
 796          *
 797          * @param $name String The special page name
 798          * @return boolean
 799          */
 800         public function isSpecial( $name ) {
 801                 if ( $this->isSpecialPage() ) {
 802                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 803                         if ( $name == $thisName ) {
 804                                 return true;
 805                         }
 806                 }
 807                 return false;
 808         }
 809
 810         /**
 811          * If the Title refers to a special page alias which is not the local default, resolve
 812          * the alias, and localise the name as necessary.  Otherwise, return $this
 813          *
 814          * @return Title
 815          */
 816         public function fixSpecialName() {
 817                 if ( $this->isSpecialPage() ) {
 818                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 819                         if ( $canonicalName ) {
 820                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 821                                 if ( $localName != $this->mDbkeyform ) {
 822                                         return Title::makeTitle( NS_SPECIAL, $localName );
 823                                 }
 824                         }
 825                 }
 826                 return $this;
 827         }
 828
 829         /**
 830          * Returns true if the title is inside the specified namespace.
 831          *
 832          * Please make use of this instead of comparing to getNamespace()
 833          * This function is much more resistant to changes we may make
 834          * to namespaces than code that makes direct comparisons.
 835          * @param $ns int The namespace
 836          * @return bool
 837          * @since 1.19
 838          */
 839         public function inNamespace( $ns ) {
 840                 return MWNamespace::equals( $this->getNamespace(), $ns );
 841         }
 842
 843         /**
 844          * Returns true if the title is inside one of the specified namespaces.
 845          *
 846          * @param ...$namespaces The namespaces to check for
 847          * @return bool
 848          * @since 1.19
 849          */
 850         public function inNamespaces( /* ... */ ) {
 851                 $namespaces = func_get_args();
 852                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 853                         $namespaces = $namespaces[0];
 854                 }
 855
 856                 foreach ( $namespaces as $ns ) {
 857                         if ( $this->inNamespace( $ns ) ) {
 858                                 return true;
 859                         }
 860                 }
 861
 862                 return false;
 863         }
 864
 865         /**
 866          * Returns true if the title has the same subject namespace as the
 867          * namespace specified.
 868          * For example this method will take NS_USER and return true if namespace
 869          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 870          * as their subject namespace.
 871          *
 872          * This is MUCH simpler than individually testing for equivilance
 873          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 874          * @since 1.19
 875          * @param $ns int
 876          * @return bool
 877          */
 878         public function hasSubjectNamespace( $ns ) {
 879                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 880         }
 881
 882         /**
 883          * Is this Title in a namespace which contains content?
 884          * In other words, is this a content page, for the purposes of calculating
 885          * statistics, etc?
 886          *
 887          * @return Boolean
 888          */
 889         public function isContentPage() {
 890                 return MWNamespace::isContent( $this->getNamespace() );
 891         }
 892
 893         /**
 894          * Would anybody with sufficient privileges be able to move this page?
 895          * Some pages just aren't movable.
 896          *
 897          * @return Bool TRUE or FALSE
 898          */
 899         public function isMovable() {
 900                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 901                         // Interwiki title or immovable namespace. Hooks don't get to override here
 902                         return false;
 903                 }
 904
 905                 $result = true;
 906                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 907                 return $result;
 908         }
 909
 910         /**
 911          * Is this the mainpage?
 912          * @note Title::newFromText seems to be sufficiently optimized by the title
 913          * cache that we don't need to over-optimize by doing direct comparisons and
 914          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 915          * ends up reporting something differently than $title->isMainPage();
 916          *
 917          * @since 1.18
 918          * @return Bool
 919          */
 920         public function isMainPage() {
 921                 return $this->equals( Title::newMainPage() );
 922         }
 923
 924         /**
 925          * Is this a subpage?
 926          *
 927          * @return Bool
 928          */
 929         public function isSubpage() {
 930                 return MWNamespace::hasSubpages( $this->mNamespace )
 931                         ? strpos( $this->getText(), '/' ) !== false
 932                         : false;
 933         }
 934
 935         /**
 936          * Is this a conversion table for the LanguageConverter?
 937          *
 938          * @return Bool
 939          */
 940         public function isConversionTable() {
 941                 //@todo: ConversionTable should become a separate content model.
 942
 943                 return $this->getNamespace() == NS_MEDIAWIKI &&
 944                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 945         }
 946
 947         /**
 948          * Does that page contain wikitext, or it is JS, CSS or whatever?
 949          *
 950          * @return Bool
 951          */
 952         public function isWikitextPage() {
 953                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 954         }
 955
 956         /**
 957          * Could this page contain custom CSS or JavaScript for the global UI.
 958          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 959          * or CONTENT_MODEL_JAVASCRIPT.
 960          *
 961          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 962          *
 963          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 964          *
 965          * @return Bool
 966          */
 967         public function isCssOrJsPage() {
 968                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 969                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 970                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 971
 972                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 973                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 974
 975                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 976
 977                 return $isCssOrJsPage;
 978         }
 979
 980         /**
 981          * Is this a .css or .js subpage of a user page?
 982          * @return Bool
 983          */
 984         public function isCssJsSubpage() {
 985                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 986                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 987                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 988         }
 989
 990         /**
 991          * Trim down a .css or .js subpage title to get the corresponding skin name
 992          *
 993          * @return string containing skin name from .css or .js subpage title
 994          */
 995         public function getSkinFromCssJsSubpage() {
 996                 $subpage = explode( '/', $this->mTextform );
 997                 $subpage = $subpage[ count( $subpage ) - 1 ];
 998                 $lastdot = strrpos( $subpage, '.' );
 999                 if ( $lastdot === false )
1000                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1001                 return substr( $subpage, 0, $lastdot );
1002         }
1003
1004         /**
1005          * Is this a .css subpage of a user page?
1006          *
1007          * @return Bool
1008          */
1009         public function isCssSubpage() {
1010                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1011                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1012         }
1013
1014         /**
1015          * Is this a .js subpage of a user page?
1016          *
1017          * @return Bool
1018          */
1019         public function isJsSubpage() {
1020                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1021                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1022         }
1023
1024         /**
1025          * Is this a talk page of some sort?
1026          *
1027          * @return Bool
1028          */
1029         public function isTalkPage() {
1030                 return MWNamespace::isTalk( $this->getNamespace() );
1031         }
1032
1033         /**
1034          * Get a Title object associated with the talk page of this article
1035          *
1036          * @return Title the object for the talk page
1037          */
1038         public function getTalkPage() {
1039                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1040         }
1041
1042         /**
1043          * Get a title object associated with the subject page of this
1044          * talk page
1045          *
1046          * @return Title the object for the subject page
1047          */
1048         public function getSubjectPage() {
1049                 // Is this the same title?
1050                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1051                 if ( $this->getNamespace() == $subjectNS ) {
1052                         return $this;
1053                 }
1054                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1055         }
1056
1057         /**
1058          * Get the default namespace index, for when there is no namespace
1059          *
1060          * @return Int Default namespace index
1061          */
1062         public function getDefaultNamespace() {
1063                 return $this->mDefaultNamespace;
1064         }
1065
1066         /**
1067          * Get title for search index
1068          *
1069          * @return String a stripped-down title string ready for the
1070          *  search index
1071          */
1072         public function getIndexTitle() {
1073                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1074         }
1075
1076         /**
1077          * Get the Title fragment (i.e.\ the bit after the #) in text form
1078          *
1079          * @return String Title fragment
1080          */
1081         public function getFragment() {
1082                 return $this->mFragment;
1083         }
1084
1085         /**
1086          * Get the fragment in URL form, including the "#" character if there is one
1087          * @return String Fragment in URL form
1088          */
1089         public function getFragmentForURL() {
1090                 if ( $this->mFragment == '' ) {
1091                         return '';
1092                 } else {
1093                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1094                 }
1095         }
1096
1097         /**
1098          * Set the fragment for this title. Removes the first character from the
1099          * specified fragment before setting, so it assumes you're passing it with
1100          * an initial "#".
1101          *
1102          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1103          * Still in active use privately.
1104          *
1105          * @param $fragment String text
1106          */
1107         public function setFragment( $fragment ) {
1108                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1109         }
1110
1111         /**
1112          * Prefix some arbitrary text with the namespace or interwiki prefix
1113          * of this object
1114          *
1115          * @param $name String the text
1116          * @return String the prefixed text
1117          * @private
1118          */
1119         private function prefix( $name ) {
1120                 $p = '';
1121                 if ( $this->mInterwiki != '' ) {
1122                         $p = $this->mInterwiki . ':';
1123                 }
1124
1125                 if ( 0 != $this->mNamespace ) {
1126                         $p .= $this->getNsText() . ':';
1127                 }
1128                 return $p . $name;
1129         }
1130
1131         /**
1132          * Get the prefixed database key form
1133          *
1134          * @return String the prefixed title, with underscores and
1135          *  any interwiki and namespace prefixes
1136          */
1137         public function getPrefixedDBkey() {
1138                 $s = $this->prefix( $this->mDbkeyform );
1139                 $s = str_replace( ' ', '_', $s );
1140                 return $s;
1141         }
1142
1143         /**
1144          * Get the prefixed title with spaces.
1145          * This is the form usually used for display
1146          *
1147          * @return String the prefixed title, with spaces
1148          */
1149         public function getPrefixedText() {
1150                 // @todo FIXME: Bad usage of empty() ?
1151                 if ( empty( $this->mPrefixedText ) ) {
1152                         $s = $this->prefix( $this->mTextform );
1153                         $s = str_replace( '_', ' ', $s );
1154                         $this->mPrefixedText = $s;
1155                 }
1156                 return $this->mPrefixedText;
1157         }
1158
1159         /**
1160          * Return a string representation of this title
1161          *
1162          * @return String representation of this title
1163          */
1164         public function __toString() {
1165                 return $this->getPrefixedText();
1166         }
1167
1168         /**
1169          * Get the prefixed title with spaces, plus any fragment
1170          * (part beginning with '#')
1171          *
1172          * @return String the prefixed title, with spaces and the fragment, including '#'
1173          */
1174         public function getFullText() {
1175                 $text = $this->getPrefixedText();
1176                 if ( $this->mFragment != '' ) {
1177                         $text .= '#' . $this->mFragment;
1178                 }
1179                 return $text;
1180         }
1181
1182         /**
1183          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1184          *
1185          * @par Example:
1186          * @code
1187          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1188          * # returns: 'Foo'
1189          * @endcode
1190          *
1191          * @return String Root name
1192          * @since 1.20
1193          */
1194         public function getRootText() {
1195                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1196                         return $this->getText();
1197                 }
1198
1199                 return strtok( $this->getText(), '/' );
1200         }
1201
1202         /**
1203          * Get the root page name title, i.e. the leftmost part before any slashes
1204          *
1205          * @par Example:
1206          * @code
1207          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1208          * # returns: Title{User:Foo}
1209          * @endcode
1210          *
1211          * @return Title Root title
1212          * @since 1.20
1213          */
1214         public function getRootTitle() {
1215                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1216         }
1217
1218         /**
1219          * Get the base page name without a namespace, i.e. the part before the subpage name
1220          *
1221          * @par Example:
1222          * @code
1223          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1224          * # returns: 'Foo/Bar'
1225          * @endcode
1226          *
1227          * @return String Base name
1228          */
1229         public function getBaseText() {
1230                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1231                         return $this->getText();
1232                 }
1233
1234                 $parts = explode( '/', $this->getText() );
1235                 # Don't discard the real title if there's no subpage involved
1236                 if ( count( $parts ) > 1 ) {
1237                         unset( $parts[count( $parts ) - 1] );
1238                 }
1239                 return implode( '/', $parts );
1240         }
1241
1242         /**
1243          * Get the base page name title, i.e. the part before the subpage name
1244          *
1245          * @par Example:
1246          * @code
1247          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1248          * # returns: Title{User:Foo/Bar}
1249          * @endcode
1250          *
1251          * @return Title Base title
1252          * @since 1.20
1253          */
1254         public function getBaseTitle() {
1255                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1256         }
1257
1258         /**
1259          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1260          *
1261          * @par Example:
1262          * @code
1263          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1264          * # returns: "Baz"
1265          * @endcode
1266          *
1267          * @return String Subpage name
1268          */
1269         public function getSubpageText() {
1270                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1271                         return( $this->mTextform );
1272                 }
1273                 $parts = explode( '/', $this->mTextform );
1274                 return( $parts[count( $parts ) - 1] );
1275         }
1276
1277         /**
1278          * Get the title for a subpage of the current page
1279          *
1280          * @par Example:
1281          * @code
1282          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1283          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1284          * @endcode
1285          *
1286          * @param $text String The subpage name to add to the title
1287          * @return Title Subpage title
1288          * @since 1.20
1289          */
1290         public function getSubpage( $text ) {
1291                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1292         }
1293
1294         /**
1295          * Get the HTML-escaped displayable text form.
1296          * Used for the title field in <a> tags.
1297          *
1298          * @return String the text, including any prefixes
1299          */
1300         public function getEscapedText() {
1301                 wfDeprecated( __METHOD__, '1.19' );
1302                 return htmlspecialchars( $this->getPrefixedText() );
1303         }
1304
1305         /**
1306          * Get a URL-encoded form of the subpage text
1307          *
1308          * @return String URL-encoded subpage name
1309          */
1310         public function getSubpageUrlForm() {
1311                 $text = $this->getSubpageText();
1312                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1313                 return( $text );
1314         }
1315
1316         /**
1317          * Get a URL-encoded title (not an actual URL) including interwiki
1318          *
1319          * @return String the URL-encoded form
1320          */
1321         public function getPrefixedURL() {
1322                 $s = $this->prefix( $this->mDbkeyform );
1323                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1324                 return $s;
1325         }
1326
1327         /**
1328          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1329          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1330          * second argument named variant. This was deprecated in favor
1331          * of passing an array of option with a "variant" key
1332          * Once $query2 is removed for good, this helper can be dropped
1333          * andthe wfArrayToCGI moved to getLocalURL();
1334          *
1335          * @since 1.19 (r105919)
1336          * @param $query
1337          * @param $query2 bool
1338          * @return String
1339          */
1340         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1341                 if( $query2 !== false ) {
1342                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1343                 }
1344                 if ( is_array( $query ) ) {
1345                         $query = wfArrayToCGI( $query );
1346                 }
1347                 if ( $query2 ) {
1348                         if ( is_string( $query2 ) ) {
1349                                 // $query2 is a string, we will consider this to be
1350                                 // a deprecated $variant argument and add it to the query
1351                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1352                         } else {
1353                                 $query2 = wfArrayToCGI( $query2 );
1354                         }
1355                         // If we have $query content add a & to it first
1356                         if ( $query ) {
1357                                 $query .= '&';
1358                         }
1359                         // Now append the queries together
1360                         $query .= $query2;
1361                 }
1362                 return $query;
1363         }
1364
1365         /**
1366          * Get a real URL referring to this title, with interwiki link and
1367          * fragment
1368          *
1369          * See getLocalURL for the arguments.
1370          *
1371          * @see self::getLocalURL
1372          * @see wfExpandUrl
1373          * @param $query
1374          * @param $query2 bool
1375          * @param $proto Protocol type to use in URL
1376          * @return String the URL
1377          */
1378         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1379                 $query = self::fixUrlQueryArgs( $query, $query2 );
1380
1381                 # Hand off all the decisions on urls to getLocalURL
1382                 $url = $this->getLocalURL( $query );
1383
1384                 # Expand the url to make it a full url. Note that getLocalURL has the
1385                 # potential to output full urls for a variety of reasons, so we use
1386                 # wfExpandUrl instead of simply prepending $wgServer
1387                 $url = wfExpandUrl( $url, $proto );
1388
1389                 # Finally, add the fragment.
1390                 $url .= $this->getFragmentForURL();
1391
1392                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1393                 return $url;
1394         }
1395
1396         /**
1397          * Get a URL with no fragment or server name.  If this page is generated
1398          * with action=render, $wgServer is prepended.
1399          *
1400
1401          * @param $query string|array an optional query string,
1402          *   not used for interwiki links. Can be specified as an associative array as well,
1403          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1404          *   Some query patterns will trigger various shorturl path replacements.
1405          * @param $query2 Mixed: An optional secondary query array. This one MUST
1406          *   be an array. If a string is passed it will be interpreted as a deprecated
1407          *   variant argument and urlencoded into a variant= argument.
1408          *   This second query argument will be added to the $query
1409          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1410          *   pair in the first parameter array instead.
1411          *
1412          * @return String the URL
1413          */
1414         public function getLocalURL( $query = '', $query2 = false ) {
1415                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1416
1417                 $query = self::fixUrlQueryArgs( $query, $query2 );
1418
1419                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1420                 if ( $interwiki ) {
1421                         $namespace = $this->getNsText();
1422                         if ( $namespace != '' ) {
1423                                 # Can this actually happen? Interwikis shouldn't be parsed.
1424                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1425                                 $namespace .= ':';
1426                         }
1427                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1428                         $url = wfAppendQuery( $url, $query );
1429                 } else {
1430                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1431                         if ( $query == '' ) {
1432                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1433                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1434                         } else {
1435                                 global $wgVariantArticlePath, $wgActionPaths;
1436                                 $url = false;
1437                                 $matches = array();
1438
1439                                 if ( !empty( $wgActionPaths ) &&
1440                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1441                                 {
1442                                         $action = urldecode( $matches[2] );
1443                                         if ( isset( $wgActionPaths[$action] ) ) {
1444                                                 $query = $matches[1];
1445                                                 if ( isset( $matches[4] ) ) {
1446                                                         $query .= $matches[4];
1447                                                 }
1448                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1449                                                 if ( $query != '' ) {
1450                                                         $url = wfAppendQuery( $url, $query );
1451                                                 }
1452                                         }
1453                                 }
1454
1455                                 if ( $url === false &&
1456                                         $wgVariantArticlePath &&
1457                                         $this->getPageLanguage()->hasVariants() &&
1458                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1459                                 {
1460                                         $variant = urldecode( $matches[1] );
1461                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1462                                                 // Only do the variant replacement if the given variant is a valid
1463                                                 // variant for the page's language.
1464                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1465                                                 $url = str_replace( '$1', $dbkey, $url );
1466                                         }
1467                                 }
1468
1469                                 if ( $url === false ) {
1470                                         if ( $query == '-' ) {
1471                                                 $query = '';
1472                                         }
1473                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1474                                 }
1475                         }
1476
1477                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1478
1479                         // @todo FIXME: This causes breakage in various places when we
1480                         // actually expected a local URL and end up with dupe prefixes.
1481                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1482                                 $url = $wgServer . $url;
1483                         }
1484                 }
1485                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1486                 return $url;
1487         }
1488
1489         /**
1490          * Get a URL that's the simplest URL that will be valid to link, locally,
1491          * to the current Title.  It includes the fragment, but does not include
1492          * the server unless action=render is used (or the link is external).  If
1493          * there's a fragment but the prefixed text is empty, we just return a link
1494          * to the fragment.
1495          *
1496          * The result obviously should not be URL-escaped, but does need to be
1497          * HTML-escaped if it's being output in HTML.
1498          *
1499          * See getLocalURL for the arguments.
1500          *
1501          * @param $query
1502          * @param $query2 bool
1503          * @param $proto Protocol to use; setting this will cause a full URL to be used
1504          * @see self::getLocalURL
1505          * @return String the URL
1506          */
1507         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1508                 wfProfileIn( __METHOD__ );
1509                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1510                         $ret = $this->getFullURL( $query, $query2, $proto );
1511                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1512                         $ret = $this->getFragmentForURL();
1513                 } else {
1514                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1515                 }
1516                 wfProfileOut( __METHOD__ );
1517                 return $ret;
1518         }
1519
1520         /**
1521          * Get an HTML-escaped version of the URL form, suitable for
1522          * using in a link, without a server name or fragment
1523          *
1524          * See getLocalURL for the arguments.
1525          *
1526          * @see self::getLocalURL
1527          * @param $query string
1528          * @param $query2 bool|string
1529          * @return String the URL
1530          */
1531         public function escapeLocalURL( $query = '', $query2 = false ) {
1532                 wfDeprecated( __METHOD__, '1.19' );
1533                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1534         }
1535
1536         /**
1537          * Get an HTML-escaped version of the URL form, suitable for
1538          * using in a link, including the server name and fragment
1539          *
1540          * See getLocalURL for the arguments.
1541          *
1542          * @see self::getLocalURL
1543          * @return String the URL
1544          */
1545         public function escapeFullURL( $query = '', $query2 = false ) {
1546                 wfDeprecated( __METHOD__, '1.19' );
1547                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1548         }
1549
1550         /**
1551          * Get the URL form for an internal link.
1552          * - Used in various Squid-related code, in case we have a different
1553          * internal hostname for the server from the exposed one.
1554          *
1555          * This uses $wgInternalServer to qualify the path, or $wgServer
1556          * if $wgInternalServer is not set. If the server variable used is
1557          * protocol-relative, the URL will be expanded to http://
1558          *
1559          * See getLocalURL for the arguments.
1560          *
1561          * @see self::getLocalURL
1562          * @return String the URL
1563          */
1564         public function getInternalURL( $query = '', $query2 = false ) {
1565                 global $wgInternalServer, $wgServer;
1566                 $query = self::fixUrlQueryArgs( $query, $query2 );
1567                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1568                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1569                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1570                 return $url;
1571         }
1572
1573         /**
1574          * Get the URL for a canonical link, for use in things like IRC and
1575          * e-mail notifications. Uses $wgCanonicalServer and the
1576          * GetCanonicalURL hook.
1577          *
1578          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1579          *
1580          * See getLocalURL for the arguments.
1581          *
1582          * @see self::getLocalURL
1583          * @return string The URL
1584          * @since 1.18
1585          */
1586         public function getCanonicalURL( $query = '', $query2 = false ) {
1587                 $query = self::fixUrlQueryArgs( $query, $query2 );
1588                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1589                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1590                 return $url;
1591         }
1592
1593         /**
1594          * HTML-escaped version of getCanonicalURL()
1595          *
1596          * See getLocalURL for the arguments.
1597          *
1598          * @see self::getLocalURL
1599          * @since 1.18
1600          * @return string
1601          */
1602         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1603                 wfDeprecated( __METHOD__, '1.19' );
1604                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1605         }
1606
1607         /**
1608          * Get the edit URL for this Title
1609          *
1610          * @return String the URL, or a null string if this is an
1611          *  interwiki link
1612          */
1613         public function getEditURL() {
1614                 if ( $this->mInterwiki != '' ) {
1615                         return '';
1616                 }
1617                 $s = $this->getLocalURL( 'action=edit' );
1618
1619                 return $s;
1620         }
1621
1622         /**
1623          * Is $wgUser watching this page?
1624          *
1625          * @deprecated in 1.20; use User::isWatched() instead.
1626          * @return Bool
1627          */
1628         public function userIsWatching() {
1629                 global $wgUser;
1630
1631                 if ( is_null( $this->mWatched ) ) {
1632                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1633                                 $this->mWatched = false;
1634                         } else {
1635                                 $this->mWatched = $wgUser->isWatched( $this );
1636                         }
1637                 }
1638                 return $this->mWatched;
1639         }
1640
1641         /**
1642          * Can $wgUser read this page?
1643          *
1644          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1645          * @return Bool
1646          * @todo fold these checks into userCan()
1647          */
1648         public function userCanRead() {
1649                 wfDeprecated( __METHOD__, '1.19' );
1650                 return $this->userCan( 'read' );
1651         }
1652
1653         /**
1654          * Can $user perform $action on this page?
1655          * This skips potentially expensive cascading permission checks
1656          * as well as avoids expensive error formatting
1657          *
1658          * Suitable for use for nonessential UI controls in common cases, but
1659          * _not_ for functional access control.
1660          *
1661          * May provide false positives, but should never provide a false negative.
1662          *
1663          * @param $action String action that permission needs to be checked for
1664          * @param $user User to check (since 1.19); $wgUser will be used if not
1665          *              provided.
1666          * @return Bool
1667          */
1668         public function quickUserCan( $action, $user = null ) {
1669                 return $this->userCan( $action, $user, false );
1670         }
1671
1672         /**
1673          * Can $user perform $action on this page?
1674          *
1675          * @param $action String action that permission needs to be checked for
1676          * @param $user User to check (since 1.19); $wgUser will be used if not
1677          *   provided.
1678          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1679          *   unnecessary queries.
1680          * @return Bool
1681          */
1682         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1683                 if ( !$user instanceof User ) {
1684                         global $wgUser;
1685                         $user = $wgUser;
1686                 }
1687                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1688         }
1689
1690         /**
1691          * Can $user perform $action on this page?
1692          *
1693          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1694          *
1695          * @param $action String action that permission needs to be checked for
1696          * @param $user User to check
1697          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1698          *   queries by skipping checks for cascading protections and user blocks.
1699          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1700          *   whose corresponding errors may be ignored.
1701          * @return Array of arguments to wfMessage to explain permissions problems.
1702          */
1703         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1704                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1705
1706                 // Remove the errors being ignored.
1707                 foreach ( $errors as $index => $error ) {
1708                         $error_key = is_array( $error ) ? $error[0] : $error;
1709
1710                         if ( in_array( $error_key, $ignoreErrors ) ) {
1711                                 unset( $errors[$index] );
1712                         }
1713                 }
1714
1715                 return $errors;
1716         }
1717
1718         /**
1719          * Permissions checks that fail most often, and which are easiest to test.
1720          *
1721          * @param $action String the action to check
1722          * @param $user User user to check
1723          * @param $errors Array list of current errors
1724          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1725          * @param $short Boolean short circuit on first error
1726          *
1727          * @return Array list of errors
1728          */
1729         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1730                 if ( $action == 'create' ) {
1731                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1732                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1733                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1734                         }
1735                 } elseif ( $action == 'move' ) {
1736                         if ( !$user->isAllowed( 'move-rootuserpages' )
1737                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1738                                 // Show user page-specific message only if the user can move other pages
1739                                 $errors[] = array( 'cant-move-user-page' );
1740                         }
1741
1742                         // Check if user is allowed to move files if it's a file
1743                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1744                                 $errors[] = array( 'movenotallowedfile' );
1745                         }
1746
1747                         if ( !$user->isAllowed( 'move' ) ) {
1748                                 // User can't move anything
1749                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1750                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1751                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1752                                         // custom message if logged-in users without any special rights can move
1753                                         $errors[] = array( 'movenologintext' );
1754                                 } else {
1755                                         $errors[] = array( 'movenotallowed' );
1756                                 }
1757                         }
1758                 } elseif ( $action == 'move-target' ) {
1759                         if ( !$user->isAllowed( 'move' ) ) {
1760                                 // User can't move anything
1761                                 $errors[] = array( 'movenotallowed' );
1762                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1763                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1764                                 // Show user page-specific message only if the user can move other pages
1765                                 $errors[] = array( 'cant-move-to-user-page' );
1766                         }
1767                 } elseif ( !$user->isAllowed( $action ) ) {
1768                         $errors[] = $this->missingPermissionError( $action, $short );
1769                 }
1770
1771                 return $errors;
1772         }
1773
1774         /**
1775          * Add the resulting error code to the errors array
1776          *
1777          * @param $errors Array list of current errors
1778          * @param $result Mixed result of errors
1779          *
1780          * @return Array list of errors
1781          */
1782         private function resultToError( $errors, $result ) {
1783                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1784                         // A single array representing an error
1785                         $errors[] = $result;
1786                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1787                         // A nested array representing multiple errors
1788                         $errors = array_merge( $errors, $result );
1789                 } elseif ( $result !== '' && is_string( $result ) ) {
1790                         // A string representing a message-id
1791                         $errors[] = array( $result );
1792                 } elseif ( $result === false ) {
1793                         // a generic "We don't want them to do that"
1794                         $errors[] = array( 'badaccess-group0' );
1795                 }
1796                 return $errors;
1797         }
1798
1799         /**
1800          * Check various permission hooks
1801          *
1802          * @param $action String the action to check
1803          * @param $user User user to check
1804          * @param $errors Array list of current errors
1805          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1806          * @param $short Boolean short circuit on first error
1807          *
1808          * @return Array list of errors
1809          */
1810         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1811                 // Use getUserPermissionsErrors instead
1812                 $result = '';
1813                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1814                         return $result ? array() : array( array( 'badaccess-group0' ) );
1815                 }
1816                 // Check getUserPermissionsErrors hook
1817                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1818                         $errors = $this->resultToError( $errors, $result );
1819                 }
1820                 // Check getUserPermissionsErrorsExpensive hook
1821                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1822                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1823                         $errors = $this->resultToError( $errors, $result );
1824                 }
1825
1826                 return $errors;
1827         }
1828
1829         /**
1830          * Check permissions on special pages & namespaces
1831          *
1832          * @param $action String the action to check
1833          * @param $user User user to check
1834          * @param $errors Array list of current errors
1835          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1836          * @param $short Boolean short circuit on first error
1837          *
1838          * @return Array list of errors
1839          */
1840         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1841                 # Only 'createaccount' and 'execute' can be performed on
1842                 # special pages, which don't actually exist in the DB.
1843                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1844                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1845                         $errors[] = array( 'ns-specialprotected' );
1846                 }
1847
1848                 # Check $wgNamespaceProtection for restricted namespaces
1849                 if ( $this->isNamespaceProtected( $user ) ) {
1850                         $ns = $this->mNamespace == NS_MAIN ?
1851                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1852                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1853                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1854                 }
1855
1856                 return $errors;
1857         }
1858
1859         /**
1860          * Check CSS/JS sub-page permissions
1861          *
1862          * @param $action String the action to check
1863          * @param $user User user to check
1864          * @param $errors Array list of current errors
1865          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1866          * @param $short Boolean short circuit on first error
1867          *
1868          * @return Array list of errors
1869          */
1870         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1871                 # Protect css/js subpages of user pages
1872                 # XXX: this might be better using restrictions
1873                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1874                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1875                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1876                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1877                                 $errors[] = array( 'customcssprotected' );
1878                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1879                                 $errors[] = array( 'customjsprotected' );
1880                         }
1881                 }
1882
1883                 return $errors;
1884         }
1885
1886         /**
1887          * Check against page_restrictions table requirements on this
1888          * page. The user must possess all required rights for this
1889          * action.
1890          *
1891          * @param $action String the action to check
1892          * @param $user User user to check
1893          * @param $errors Array list of current errors
1894          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1895          * @param $short Boolean short circuit on first error
1896          *
1897          * @return Array list of errors
1898          */
1899         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1900                 foreach ( $this->getRestrictions( $action ) as $right ) {
1901                         // Backwards compatibility, rewrite sysop -> protect
1902                         if ( $right == 'sysop' ) {
1903                                 $right = 'protect';
1904                         }
1905                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1906                                 // Users with 'editprotected' permission can edit protected pages
1907                                 // without cascading option turned on.
1908                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1909                                         || $this->mCascadeRestriction )
1910                                 {
1911                                         $errors[] = array( 'protectedpagetext', $right );
1912                                 }
1913                         }
1914                 }
1915
1916                 return $errors;
1917         }
1918
1919         /**
1920          * Check restrictions on cascading pages.
1921          *
1922          * @param $action String the action to check
1923          * @param $user User to check
1924          * @param $errors Array list of current errors
1925          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1926          * @param $short Boolean short circuit on first error
1927          *
1928          * @return Array list of errors
1929          */
1930         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1931                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1932                         # We /could/ use the protection level on the source page, but it's
1933                         # fairly ugly as we have to establish a precedence hierarchy for pages
1934                         # included by multiple cascade-protected pages. So just restrict
1935                         # it to people with 'protect' permission, as they could remove the
1936                         # protection anyway.
1937                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1938                         # Cascading protection depends on more than this page...
1939                         # Several cascading protected pages may include this page...
1940                         # Check each cascading level
1941                         # This is only for protection restrictions, not for all actions
1942                         if ( isset( $restrictions[$action] ) ) {
1943                                 foreach ( $restrictions[$action] as $right ) {
1944                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1945                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1946                                                 $pages = '';
1947                                                 foreach ( $cascadingSources as $page )
1948                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1949                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1950                                         }
1951                                 }
1952                         }
1953                 }
1954
1955                 return $errors;
1956         }
1957
1958         /**
1959          * Check action permissions not already checked in checkQuickPermissions
1960          *
1961          * @param $action String the action to check
1962          * @param $user User to check
1963          * @param $errors Array list of current errors
1964          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1965          * @param $short Boolean short circuit on first error
1966          *
1967          * @return Array list of errors
1968          */
1969         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1970                 global $wgDeleteRevisionsLimit, $wgLang;
1971
1972                 if ( $action == 'protect' ) {
1973                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1974                                 // If they can't edit, they shouldn't protect.
1975                                 $errors[] = array( 'protect-cantedit' );
1976                         }
1977                 } elseif ( $action == 'create' ) {
1978                         $title_protection = $this->getTitleProtection();
1979                         if( $title_protection ) {
1980                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1981                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1982                                 }
1983                                 if( $title_protection['pt_create_perm'] == '' ||
1984                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1985                                 {
1986                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1987                                 }
1988                         }
1989                 } elseif ( $action == 'move' ) {
1990                         // Check for immobile pages
1991                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1992                                 // Specific message for this case
1993                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1994                         } elseif ( !$this->isMovable() ) {
1995                                 // Less specific message for rarer cases
1996                                 $errors[] = array( 'immobile-source-page' );
1997                         }
1998                 } elseif ( $action == 'move-target' ) {
1999                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2000                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2001                         } elseif ( !$this->isMovable() ) {
2002                                 $errors[] = array( 'immobile-target-page' );
2003                         }
2004                 } elseif ( $action == 'delete' ) {
2005                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2006                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
2007                         {
2008                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2009                         }
2010                 }
2011                 return $errors;
2012         }
2013
2014         /**
2015          * Check that the user isn't blocked from editting.
2016          *
2017          * @param $action String the action to check
2018          * @param $user User to check
2019          * @param $errors Array list of current errors
2020          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2021          * @param $short Boolean short circuit on first error
2022          *
2023          * @return Array list of errors
2024          */
2025         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2026                 // Account creation blocks handled at userlogin.
2027                 // Unblocking handled in SpecialUnblock
2028                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2029                         return $errors;
2030                 }
2031
2032                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
2033
2034                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2035                         $errors[] = array( 'confirmedittext' );
2036                 }
2037
2038                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2039                         // Don't block the user from editing their own talk page unless they've been
2040                         // explicitly blocked from that too.
2041                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2042                         $block = $user->getBlock();
2043
2044                         // This is from OutputPage::blockedPage
2045                         // Copied at r23888 by werdna
2046
2047                         $id = $user->blockedBy();
2048                         $reason = $user->blockedFor();
2049                         if ( $reason == '' ) {
2050                                 $reason = wfMessage( 'blockednoreason' )->text();
2051                         }
2052                         $ip = $user->getRequest()->getIP();
2053
2054                         if ( is_numeric( $id ) ) {
2055                                 $name = User::whoIs( $id );
2056                         } else {
2057                                 $name = $id;
2058                         }
2059
2060                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2061                         $blockid = $block->getId();
2062                         $blockExpiry = $block->getExpiry();
2063                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2064                         if ( $blockExpiry == 'infinity' ) {
2065                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2066                         } else {
2067                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2068                         }
2069
2070                         $intended = strval( $block->getTarget() );
2071
2072                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2073                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2074                 }
2075
2076                 return $errors;
2077         }
2078
2079         /**
2080          * Check that the user is allowed to read this page.
2081          *
2082          * @param $action String the action to check
2083          * @param $user User to check
2084          * @param $errors Array list of current errors
2085          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2086          * @param $short Boolean short circuit on first error
2087          *
2088          * @return Array list of errors
2089          */
2090         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2091                 global $wgWhitelistRead, $wgRevokePermissions;
2092                 static $useShortcut = null;
2093
2094                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2095                 if ( is_null( $useShortcut ) ) {
2096                         $useShortcut = true;
2097                         if ( !User::groupHasPermission( '*', 'read' ) ) {
2098                                 # Not a public wiki, so no shortcut
2099                                 $useShortcut = false;
2100                         } elseif ( !empty( $wgRevokePermissions ) ) {
2101                                 /**
2102                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2103                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2104                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2105                                  * reading is allowed.
2106                                  */
2107                                 foreach ( $wgRevokePermissions as $perms ) {
2108                                         if ( !empty( $perms['read'] ) ) {
2109                                                 # We might be removing the read right from the user, so no shortcut
2110                                                 $useShortcut = false;
2111                                                 break;
2112                                         }
2113                                 }
2114                         }
2115                 }
2116
2117                 $whitelisted = false;
2118                 if ( $useShortcut ) {
2119                         # Shortcut for public wikis, allows skipping quite a bit of code
2120                         $whitelisted = true;
2121                 } elseif ( $user->isAllowed( 'read' ) ) {
2122                         # If the user is allowed to read pages, he is allowed to read all pages
2123                         $whitelisted = true;
2124                 } elseif ( $this->isSpecial( 'Userlogin' )
2125                         || $this->isSpecial( 'ChangePassword' )
2126                         || $this->isSpecial( 'PasswordReset' )
2127                 ) {
2128                         # Always grant access to the login page.
2129                         # Even anons need to be able to log in.
2130                         $whitelisted = true;
2131                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2132                         # Time to check the whitelist
2133                         # Only do these checks is there's something to check against
2134                         $name = $this->getPrefixedText();
2135                         $dbName = $this->getPrefixedDBKey();
2136
2137                         // Check for explicit whitelisting with and without underscores
2138                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2139                                 $whitelisted = true;
2140                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2141                                 # Old settings might have the title prefixed with
2142                                 # a colon for main-namespace pages
2143                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2144                                         $whitelisted = true;
2145                                 }
2146                         } elseif ( $this->isSpecialPage() ) {
2147                                 # If it's a special page, ditch the subpage bit and check again
2148                                 $name = $this->getDBkey();
2149                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2150                                 if ( $name !== false ) {
2151                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2152                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2153                                                 $whitelisted = true;
2154                                         }
2155                                 }
2156                         }
2157                 }
2158
2159                 if ( !$whitelisted ) {
2160                         # If the title is not whitelisted, give extensions a chance to do so...
2161                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2162                         if ( !$whitelisted ) {
2163                                 $errors[] = $this->missingPermissionError( $action, $short );
2164                         }
2165                 }
2166
2167                 return $errors;
2168         }
2169
2170         /**
2171          * Get a description array when the user doesn't have the right to perform
2172          * $action (i.e. when User::isAllowed() returns false)
2173          *
2174          * @param $action String the action to check
2175          * @param $short Boolean short circuit on first error
2176          * @return Array list of errors
2177          */
2178         private function missingPermissionError( $action, $short ) {
2179                 // We avoid expensive display logic for quickUserCan's and such
2180                 if ( $short ) {
2181                         return array( 'badaccess-group0' );
2182                 }
2183
2184                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2185                         User::getGroupsWithPermission( $action ) );
2186
2187                 if ( count( $groups ) ) {
2188                         global $wgLang;
2189                         return array(
2190                                 'badaccess-groups',
2191                                 $wgLang->commaList( $groups ),
2192                                 count( $groups )
2193                         );
2194                 } else {
2195                         return array( 'badaccess-group0' );
2196                 }
2197         }
2198
2199         /**
2200          * Can $user perform $action on this page? This is an internal function,
2201          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2202          * checks on wfReadOnly() and blocks)
2203          *
2204          * @param $action String action that permission needs to be checked for
2205          * @param $user User to check
2206          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2207          * @param $short Bool Set this to true to stop after the first permission error.
2208          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2209          */
2210         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2211                 wfProfileIn( __METHOD__ );
2212
2213                 # Read has special handling
2214                 if ( $action == 'read' ) {
2215                         $checks = array(
2216                                 'checkPermissionHooks',
2217                                 'checkReadPermissions',
2218                         );
2219                 } else {
2220                         $checks = array(
2221                                 'checkQuickPermissions',
2222                                 'checkPermissionHooks',
2223                                 'checkSpecialsAndNSPermissions',
2224                                 'checkCSSandJSPermissions',
2225                                 'checkPageRestrictions',
2226                                 'checkCascadingSourcesRestrictions',
2227                                 'checkActionPermissions',
2228                                 'checkUserBlock'
2229                         );
2230                 }
2231
2232                 $errors = array();
2233                 while( count( $checks ) > 0 &&
2234                                 !( $short && count( $errors ) > 0 ) ) {
2235                         $method = array_shift( $checks );
2236                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2237                 }
2238
2239                 wfProfileOut( __METHOD__ );
2240                 return $errors;
2241         }
2242
2243         /**
2244          * Protect css subpages of user pages: can $wgUser edit
2245          * this page?
2246          *
2247          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2248          * @return Bool
2249          */
2250         public function userCanEditCssSubpage() {
2251                 global $wgUser;
2252                 wfDeprecated( __METHOD__, '1.19' );
2253                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2254                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2255         }
2256
2257         /**
2258          * Protect js subpages of user pages: can $wgUser edit
2259          * this page?
2260          *
2261          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2262          * @return Bool
2263          */
2264         public function userCanEditJsSubpage() {
2265                 global $wgUser;
2266                 wfDeprecated( __METHOD__, '1.19' );
2267                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2268                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2269         }
2270
2271         /**
2272          * Get a filtered list of all restriction types supported by this wiki.
2273          * @param bool $exists True to get all restriction types that apply to
2274          * titles that do exist, False for all restriction types that apply to
2275          * titles that do not exist
2276          * @return array
2277          */
2278         public static function getFilteredRestrictionTypes( $exists = true ) {
2279                 global $wgRestrictionTypes;
2280                 $types = $wgRestrictionTypes;
2281                 if ( $exists ) {
2282                         # Remove the create restriction for existing titles
2283                         $types = array_diff( $types, array( 'create' ) );
2284                 } else {
2285                         # Only the create and upload restrictions apply to non-existing titles
2286                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2287                 }
2288                 return $types;
2289         }
2290
2291         /**
2292          * Returns restriction types for the current Title
2293          *
2294          * @return array applicable restriction types
2295          */
2296         public function getRestrictionTypes() {
2297                 if ( $this->isSpecialPage() ) {
2298                         return array();
2299                 }
2300
2301                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2302
2303                 if ( $this->getNamespace() != NS_FILE ) {
2304                         # Remove the upload restriction for non-file titles
2305                         $types = array_diff( $types, array( 'upload' ) );
2306                 }
2307
2308                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2309
2310                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2311                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2312
2313                 return $types;
2314         }
2315
2316         /**
2317          * Is this title subject to title protection?
2318          * Title protection is the one applied against creation of such title.
2319          *
2320          * @return Mixed An associative array representing any existent title
2321          *   protection, or false if there's none.
2322          */
2323         private function getTitleProtection() {
2324                 // Can't protect pages in special namespaces
2325                 if ( $this->getNamespace() < 0 ) {
2326                         return false;
2327                 }
2328
2329                 // Can't protect pages that exist.
2330                 if ( $this->exists() ) {
2331                         return false;
2332                 }
2333
2334                 if ( !isset( $this->mTitleProtection ) ) {
2335                         $dbr = wfGetDB( DB_SLAVE );
2336                         $res = $dbr->select( 'protected_titles', '*',
2337                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2338                                 __METHOD__ );
2339
2340                         // fetchRow returns false if there are no rows.
2341                         $this->mTitleProtection = $dbr->fetchRow( $res );
2342                 }
2343                 return $this->mTitleProtection;
2344         }
2345
2346         /**
2347          * Update the title protection status
2348          *
2349          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2350          * @param $create_perm String Permission required for creation
2351          * @param $reason String Reason for protection
2352          * @param $expiry String Expiry timestamp
2353          * @return boolean true
2354          */
2355         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2356                 wfDeprecated( __METHOD__, '1.19' );
2357
2358                 global $wgUser;
2359
2360                 $limit = array( 'create' => $create_perm );
2361                 $expiry = array( 'create' => $expiry );
2362
2363                 $page = WikiPage::factory( $this );
2364                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2365
2366                 return $status->isOK();
2367         }
2368
2369         /**
2370          * Remove any title protection due to page existing
2371          */
2372         public function deleteTitleProtection() {
2373                 $dbw = wfGetDB( DB_MASTER );
2374
2375                 $dbw->delete(
2376                         'protected_titles',
2377                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2378                         __METHOD__
2379                 );
2380                 $this->mTitleProtection = false;
2381         }
2382
2383         /**
2384          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2385          *
2386          * @param $action String Action to check (default: edit)
2387          * @return Bool
2388          */
2389         public function isSemiProtected( $action = 'edit' ) {
2390                 if ( $this->exists() ) {
2391                         $restrictions = $this->getRestrictions( $action );
2392                         if ( count( $restrictions ) > 0 ) {
2393                                 foreach ( $restrictions as $restriction ) {
2394                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2395                                                 return false;
2396                                         }
2397                                 }
2398                         } else {
2399                                 # Not protected
2400                                 return false;
2401                         }
2402                         return true;
2403                 } else {
2404                         # If it doesn't exist, it can't be protected
2405                         return false;
2406                 }
2407         }
2408
2409         /**
2410          * Does the title correspond to a protected article?
2411          *
2412          * @param $action String the action the page is protected from,
2413          * by default checks all actions.
2414          * @return Bool
2415          */
2416         public function isProtected( $action = '' ) {
2417                 global $wgRestrictionLevels;
2418
2419                 $restrictionTypes = $this->getRestrictionTypes();
2420
2421                 # Special pages have inherent protection
2422                 if( $this->isSpecialPage() ) {
2423                         return true;
2424                 }
2425
2426                 # Check regular protection levels
2427                 foreach ( $restrictionTypes as $type ) {
2428                         if ( $action == $type || $action == '' ) {
2429                                 $r = $this->getRestrictions( $type );
2430                                 foreach ( $wgRestrictionLevels as $level ) {
2431                                         if ( in_array( $level, $r ) && $level != '' ) {
2432                                                 return true;
2433                                         }
2434                                 }
2435                         }
2436                 }
2437
2438                 return false;
2439         }
2440
2441         /**
2442          * Determines if $user is unable to edit this page because it has been protected
2443          * by $wgNamespaceProtection.
2444          *
2445          * @param $user User object to check permissions
2446          * @return Bool
2447          */
2448         public function isNamespaceProtected( User $user ) {
2449                 global $wgNamespaceProtection;
2450
2451                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2452                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2453                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2454                                         return true;
2455                                 }
2456                         }
2457                 }
2458                 return false;
2459         }
2460
2461         /**
2462          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2463          *
2464          * @return Bool If the page is subject to cascading restrictions.
2465          */
2466         public function isCascadeProtected() {
2467                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2468                 return ( $sources > 0 );
2469         }
2470
2471         /**
2472          * Cascading protection: Get the source of any cascading restrictions on this page.
2473          *
2474          * @param $getPages Bool Whether or not to retrieve the actual pages
2475          *        that the restrictions have come from.
2476          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2477          *     have come, false for none, or true if such restrictions exist, but $getPages
2478          *     was not set.  The restriction array is an array of each type, each of which
2479          *     contains a array of unique groups.
2480          */
2481         public function getCascadeProtectionSources( $getPages = true ) {
2482                 global $wgContLang;
2483                 $pagerestrictions = array();
2484
2485                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2486                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2487                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2488                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2489                 }
2490
2491                 wfProfileIn( __METHOD__ );
2492
2493                 $dbr = wfGetDB( DB_SLAVE );
2494
2495                 if ( $this->getNamespace() == NS_FILE ) {
2496                         $tables = array( 'imagelinks', 'page_restrictions' );
2497                         $where_clauses = array(
2498                                 'il_to' => $this->getDBkey(),
2499                                 'il_from=pr_page',
2500                                 'pr_cascade' => 1
2501                         );
2502                 } else {
2503                         $tables = array( 'templatelinks', 'page_restrictions' );
2504                         $where_clauses = array(
2505                                 'tl_namespace' => $this->getNamespace(),
2506                                 'tl_title' => $this->getDBkey(),
2507                                 'tl_from=pr_page',
2508                                 'pr_cascade' => 1
2509                         );
2510                 }
2511
2512                 if ( $getPages ) {
2513                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2514                                                    'pr_expiry', 'pr_type', 'pr_level' );
2515                         $where_clauses[] = 'page_id=pr_page';
2516                         $tables[] = 'page';
2517                 } else {
2518                         $cols = array( 'pr_expiry' );
2519                 }
2520
2521                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2522
2523                 $sources = $getPages ? array() : false;
2524                 $now = wfTimestampNow();
2525                 $purgeExpired = false;
2526
2527                 foreach ( $res as $row ) {
2528                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2529                         if ( $expiry > $now ) {
2530                                 if ( $getPages ) {
2531                                         $page_id = $row->pr_page;
2532                                         $page_ns = $row->page_namespace;
2533                                         $page_title = $row->page_title;
2534                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2535                                         # Add groups needed for each restriction type if its not already there
2536                                         # Make sure this restriction type still exists
2537
2538                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2539                                                 $pagerestrictions[$row->pr_type] = array();
2540                                         }
2541
2542                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2543                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2544                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2545                                         }
2546                                 } else {
2547                                         $sources = true;
2548                                 }
2549                         } else {
2550                                 // Trigger lazy purge of expired restrictions from the db
2551                                 $purgeExpired = true;
2552                         }
2553                 }
2554                 if ( $purgeExpired ) {
2555                         Title::purgeExpiredRestrictions();
2556                 }
2557
2558                 if ( $getPages ) {
2559                         $this->mCascadeSources = $sources;
2560                         $this->mCascadingRestrictions = $pagerestrictions;
2561                 } else {
2562                         $this->mHasCascadingRestrictions = $sources;
2563                 }
2564
2565                 wfProfileOut( __METHOD__ );
2566                 return array( $sources, $pagerestrictions );
2567         }
2568
2569         /**
2570          * Accessor/initialisation for mRestrictions
2571          *
2572          * @param $action String action that permission needs to be checked for
2573          * @return Array of Strings the array of groups allowed to edit this article
2574          */
2575         public function getRestrictions( $action ) {
2576                 if ( !$this->mRestrictionsLoaded ) {
2577                         $this->loadRestrictions();
2578                 }
2579                 return isset( $this->mRestrictions[$action] )
2580                                 ? $this->mRestrictions[$action]
2581                                 : array();
2582         }
2583
2584         /**
2585          * Get the expiry time for the restriction against a given action
2586          *
2587          * @param $action
2588          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2589          *     or not protected at all, or false if the action is not recognised.
2590          */
2591         public function getRestrictionExpiry( $action ) {
2592                 if ( !$this->mRestrictionsLoaded ) {
2593                         $this->loadRestrictions();
2594                 }
2595                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2596         }
2597
2598         /**
2599          * Returns cascading restrictions for the current article
2600          *
2601          * @return Boolean
2602          */
2603         function areRestrictionsCascading() {
2604                 if ( !$this->mRestrictionsLoaded ) {
2605                         $this->loadRestrictions();
2606                 }
2607
2608                 return $this->mCascadeRestriction;
2609         }
2610
2611         /**
2612          * Loads a string into mRestrictions array
2613          *
2614          * @param $res Resource restrictions as an SQL result.
2615          * @param $oldFashionedRestrictions String comma-separated list of page
2616          *        restrictions from page table (pre 1.10)
2617          */
2618         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2619                 $rows = array();
2620
2621                 foreach ( $res as $row ) {
2622                         $rows[] = $row;
2623                 }
2624
2625                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2626         }
2627
2628         /**
2629          * Compiles list of active page restrictions from both page table (pre 1.10)
2630          * and page_restrictions table for this existing page.
2631          * Public for usage by LiquidThreads.
2632          *
2633          * @param $rows array of db result objects
2634          * @param $oldFashionedRestrictions string comma-separated list of page
2635          *        restrictions from page table (pre 1.10)
2636          */
2637         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2638                 global $wgContLang;
2639                 $dbr = wfGetDB( DB_SLAVE );
2640
2641                 $restrictionTypes = $this->getRestrictionTypes();
2642
2643                 foreach ( $restrictionTypes as $type ) {
2644                         $this->mRestrictions[$type] = array();
2645                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2646                 }
2647
2648                 $this->mCascadeRestriction = false;
2649
2650                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2651
2652                 if ( $oldFashionedRestrictions === null ) {
2653                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2654                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2655                 }
2656
2657                 if ( $oldFashionedRestrictions != '' ) {
2658
2659                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2660                                 $temp = explode( '=', trim( $restrict ) );
2661                                 if ( count( $temp ) == 1 ) {
2662                                         // old old format should be treated as edit/move restriction
2663                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2664                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2665                                 } else {
2666                                         $restriction = trim( $temp[1] );
2667                                         if( $restriction != '' ) { //some old entries are empty
2668                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2669                                         }
2670                                 }
2671                         }
2672
2673                         $this->mOldRestrictions = true;
2674
2675                 }
2676
2677                 if ( count( $rows ) ) {
2678                         # Current system - load second to make them override.
2679                         $now = wfTimestampNow();
2680                         $purgeExpired = false;
2681
2682                         # Cycle through all the restrictions.
2683                         foreach ( $rows as $row ) {
2684
2685                                 // Don't take care of restrictions types that aren't allowed
2686                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2687                                         continue;
2688
2689                                 // This code should be refactored, now that it's being used more generally,
2690                                 // But I don't really see any harm in leaving it in Block for now -werdna
2691                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2692
2693                                 // Only apply the restrictions if they haven't expired!
2694                                 if ( !$expiry || $expiry > $now ) {
2695                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2696                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2697
2698                                         $this->mCascadeRestriction |= $row->pr_cascade;
2699                                 } else {
2700                                         // Trigger a lazy purge of expired restrictions
2701                                         $purgeExpired = true;
2702                                 }
2703                         }
2704
2705                         if ( $purgeExpired ) {
2706                                 Title::purgeExpiredRestrictions();
2707                         }
2708                 }
2709
2710                 $this->mRestrictionsLoaded = true;
2711         }
2712
2713         /**
2714          * Load restrictions from the page_restrictions table
2715          *
2716          * @param $oldFashionedRestrictions String comma-separated list of page
2717          *        restrictions from page table (pre 1.10)
2718          */
2719         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2720                 global $wgContLang;
2721                 if ( !$this->mRestrictionsLoaded ) {
2722                         if ( $this->exists() ) {
2723                                 $dbr = wfGetDB( DB_SLAVE );
2724
2725                                 $res = $dbr->select(
2726                                         'page_restrictions',
2727                                         '*',
2728                                         array( 'pr_page' => $this->getArticleID() ),
2729                                         __METHOD__
2730                                 );
2731
2732                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2733                         } else {
2734                                 $title_protection = $this->getTitleProtection();
2735
2736                                 if ( $title_protection ) {
2737                                         $now = wfTimestampNow();
2738                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2739
2740                                         if ( !$expiry || $expiry > $now ) {
2741                                                 // Apply the restrictions
2742                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2743                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2744                                         } else { // Get rid of the old restrictions
2745                                                 Title::purgeExpiredRestrictions();
2746                                                 $this->mTitleProtection = false;
2747                                         }
2748                                 } else {
2749                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2750                                 }
2751                                 $this->mRestrictionsLoaded = true;
2752                         }
2753                 }
2754         }
2755
2756         /**
2757          * Flush the protection cache in this object and force reload from the database.
2758          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2759          */
2760         public function flushRestrictions() {
2761                 $this->mRestrictionsLoaded = false;
2762                 $this->mTitleProtection = null;
2763         }
2764
2765         /**
2766          * Purge expired restrictions from the page_restrictions table
2767          */
2768         static function purgeExpiredRestrictions() {
2769                 $dbw = wfGetDB( DB_MASTER );
2770                 $dbw->delete(
2771                         'page_restrictions',
2772                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2773                         __METHOD__
2774                 );
2775
2776                 $dbw->delete(
2777                         'protected_titles',
2778                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2779                         __METHOD__
2780                 );
2781         }
2782
2783         /**
2784          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2785          *
2786          * @return Bool
2787          */
2788         public function hasSubpages() {
2789                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2790                         # Duh
2791                         return false;
2792                 }
2793
2794                 # We dynamically add a member variable for the purpose of this method
2795                 # alone to cache the result.  There's no point in having it hanging
2796                 # around uninitialized in every Title object; therefore we only add it
2797                 # if needed and don't declare it statically.
2798                 if ( isset( $this->mHasSubpages ) ) {
2799                         return $this->mHasSubpages;
2800                 }
2801
2802                 $subpages = $this->getSubpages( 1 );
2803                 if ( $subpages instanceof TitleArray ) {
2804                         return $this->mHasSubpages = (bool)$subpages->count();
2805                 }
2806                 return $this->mHasSubpages = false;
2807         }
2808
2809         /**
2810          * Get all subpages of this page.
2811          *
2812          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2813          * @return mixed TitleArray, or empty array if this page's namespace
2814          *  doesn't allow subpages
2815          */
2816         public function getSubpages( $limit = -1 ) {
2817                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2818                         return array();
2819                 }
2820
2821                 $dbr = wfGetDB( DB_SLAVE );
2822                 $conds['page_namespace'] = $this->getNamespace();
2823                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2824                 $options = array();
2825                 if ( $limit > -1 ) {
2826                         $options['LIMIT'] = $limit;
2827                 }
2828                 return $this->mSubpages = TitleArray::newFromResult(
2829                         $dbr->select( 'page',
2830                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2831                                 $conds,
2832                                 __METHOD__,
2833                                 $options
2834                         )
2835                 );
2836         }
2837
2838         /**
2839          * Is there a version of this page in the deletion archive?
2840          *
2841          * @return Int the number of archived revisions
2842          */
2843         public function isDeleted() {
2844                 if ( $this->getNamespace() < 0 ) {
2845                         $n = 0;
2846                 } else {
2847                         $dbr = wfGetDB( DB_SLAVE );
2848
2849                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2850                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2851                                 __METHOD__
2852                         );
2853                         if ( $this->getNamespace() == NS_FILE ) {
2854                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2855                                         array( 'fa_name' => $this->getDBkey() ),
2856                                         __METHOD__
2857                                 );
2858                         }
2859                 }
2860                 return (int)$n;
2861         }
2862
2863         /**
2864          * Is there a version of this page in the deletion archive?
2865          *
2866          * @return Boolean
2867          */
2868         public function isDeletedQuick() {
2869                 if ( $this->getNamespace() < 0 ) {
2870                         return false;
2871                 }
2872                 $dbr = wfGetDB( DB_SLAVE );
2873                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2874                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2875                         __METHOD__
2876                 );
2877                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2878                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2879                                 array( 'fa_name' => $this->getDBkey() ),
2880                                 __METHOD__
2881                         );
2882                 }
2883                 return $deleted;
2884         }
2885
2886         /**
2887          * Get the article ID for this Title from the link cache,
2888          * adding it if necessary
2889          *
2890          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2891          *  for update
2892          * @return Int the ID
2893          */
2894         public function getArticleID( $flags = 0 ) {
2895                 if ( $this->getNamespace() < 0 ) {
2896                         return $this->mArticleID = 0;
2897                 }
2898                 $linkCache = LinkCache::singleton();
2899                 if ( $flags & self::GAID_FOR_UPDATE ) {
2900                         $oldUpdate = $linkCache->forUpdate( true );
2901                         $linkCache->clearLink( $this );
2902                         $this->mArticleID = $linkCache->addLinkObj( $this );
2903                         $linkCache->forUpdate( $oldUpdate );
2904                 } else {
2905                         if ( -1 == $this->mArticleID ) {
2906                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2907                         }
2908                 }
2909                 return $this->mArticleID;
2910         }
2911
2912         /**
2913          * Is this an article that is a redirect page?
2914          * Uses link cache, adding it if necessary
2915          *
2916          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2917          * @return Bool
2918          */
2919         public function isRedirect( $flags = 0 ) {
2920                 if ( !is_null( $this->mRedirect ) ) {
2921                         return $this->mRedirect;
2922                 }
2923                 # Calling getArticleID() loads the field from cache as needed
2924                 if ( !$this->getArticleID( $flags ) ) {
2925                         return $this->mRedirect = false;
2926                 }
2927
2928                 $linkCache = LinkCache::singleton();
2929                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2930                 if ( $cached === null ) {
2931                         // TODO: check the assumption that the cache actually knows about this title
2932                         // and handle this, such as get the title from the database.
2933                         // See https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2934                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2935                         wfDebug( wfBacktrace() );
2936                 }
2937
2938                 $this->mRedirect = (bool)$cached;
2939
2940                 return $this->mRedirect;
2941         }
2942
2943         /**
2944          * What is the length of this page?
2945          * Uses link cache, adding it if necessary
2946          *
2947          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2948          * @return Int
2949          */
2950         public function getLength( $flags = 0 ) {
2951                 if ( $this->mLength != -1 ) {
2952                         return $this->mLength;
2953                 }
2954                 # Calling getArticleID() loads the field from cache as needed
2955                 if ( !$this->getArticleID( $flags ) ) {
2956                         return $this->mLength = 0;
2957                 }
2958                 $linkCache = LinkCache::singleton();
2959                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2960                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2961                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2962                         #      as a stop gap, perhaps log this, but don't throw an exception?
2963                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2964                         wfDebug( wfBacktrace() );
2965                 }
2966
2967                 $this->mLength = intval( $cached );
2968
2969                 return $this->mLength;
2970         }
2971
2972         /**
2973          * What is the page_latest field for this page?
2974          *
2975          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2976          * @throws MWException
2977          * @return Int or 0 if the page doesn't exist
2978          */
2979         public function getLatestRevID( $flags = 0 ) {
2980                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
2981                         return intval( $this->mLatestID );
2982                 }
2983                 # Calling getArticleID() loads the field from cache as needed
2984                 if ( !$this->getArticleID( $flags ) ) {
2985                         return $this->mLatestID = 0;
2986                 }
2987                 $linkCache = LinkCache::singleton();
2988                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
2989                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2990                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2991                         #      as a stop gap, perhaps log this, but don't throw an exception?
2992                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2993                 }
2994
2995                 $this->mLatestID = intval( $cached );
2996
2997                 return $this->mLatestID;
2998         }
2999
3000         /**
3001          * This clears some fields in this object, and clears any associated
3002          * keys in the "bad links" section of the link cache.
3003          *
3004          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3005          * loading of the new page_id. It's also called from
3006          * WikiPage::doDeleteArticleReal()
3007          *
3008          * @param $newid Int the new Article ID
3009          */
3010         public function resetArticleID( $newid ) {
3011                 $linkCache = LinkCache::singleton();
3012                 $linkCache->clearLink( $this );
3013
3014                 if ( $newid === false ) {
3015                         $this->mArticleID = -1;
3016                 } else {
3017                         $this->mArticleID = intval( $newid );
3018                 }
3019                 $this->mRestrictionsLoaded = false;
3020                 $this->mRestrictions = array();
3021                 $this->mRedirect = null;
3022                 $this->mLength = -1;
3023                 $this->mLatestID = false;
3024                 $this->mContentModel = false;
3025                 $this->mEstimateRevisions = null;
3026         }
3027
3028         /**
3029          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3030          *
3031          * @param $text String containing title to capitalize
3032          * @param $ns int namespace index, defaults to NS_MAIN
3033          * @return String containing capitalized title
3034          */
3035         public static function capitalize( $text, $ns = NS_MAIN ) {
3036                 global $wgContLang;
3037
3038                 if ( MWNamespace::isCapitalized( $ns ) ) {
3039                         return $wgContLang->ucfirst( $text );
3040                 } else {
3041                         return $text;
3042                 }
3043         }
3044
3045         /**
3046          * Secure and split - main initialisation function for this object
3047          *
3048          * Assumes that mDbkeyform has been set, and is urldecoded
3049          * and uses underscores, but not otherwise munged.  This function
3050          * removes illegal characters, splits off the interwiki and
3051          * namespace prefixes, sets the other forms, and canonicalizes
3052          * everything.
3053          *
3054          * @return Bool true on success
3055          */
3056         private function secureAndSplit() {
3057                 global $wgContLang, $wgLocalInterwiki;
3058
3059                 # Initialisation
3060                 $this->mInterwiki = $this->mFragment = '';
3061                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3062
3063                 $dbkey = $this->mDbkeyform;
3064
3065                 # Strip Unicode bidi override characters.
3066                 # Sometimes they slip into cut-n-pasted page titles, where the
3067                 # override chars get included in list displays.
3068                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3069
3070                 # Clean up whitespace
3071                 # Note: use of the /u option on preg_replace here will cause
3072                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3073                 # conveniently disabling them.
3074                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3075                 $dbkey = trim( $dbkey, '_' );
3076
3077                 if ( $dbkey == '' ) {
3078                         return false;
3079                 }
3080
3081                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3082                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3083                         return false;
3084                 }
3085
3086                 $this->mDbkeyform = $dbkey;
3087
3088                 # Initial colon indicates main namespace rather than specified default
3089                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3090                 if ( ':' == $dbkey[0] ) {
3091                         $this->mNamespace = NS_MAIN;
3092                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3093                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3094                 }
3095
3096                 # Namespace or interwiki prefix
3097                 $firstPass = true;
3098                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3099                 do {
3100                         $m = array();
3101                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3102                                 $p = $m[1];
3103                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3104                                         # Ordinary namespace
3105                                         $dbkey = $m[2];
3106                                         $this->mNamespace = $ns;
3107                                         # For Talk:X pages, check if X has a "namespace" prefix
3108                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3109                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3110                                                         # Disallow Talk:File:x type titles...
3111                                                         return false;
3112                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3113                                                         # Disallow Talk:Interwiki:x type titles...
3114                                                         return false;
3115                                                 }
3116                                         }
3117                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3118                                         if ( !$firstPass ) {
3119                                                 # Can't make a local interwiki link to an interwiki link.
3120                                                 # That's just crazy!
3121                                                 return false;
3122                                         }
3123
3124                                         # Interwiki link
3125                                         $dbkey = $m[2];
3126                                         $this->mInterwiki = $wgContLang->lc( $p );
3127
3128                                         # Redundant interwiki prefix to the local wiki
3129                                         if ( $wgLocalInterwiki !== false
3130                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3131                                         {
3132                                                 if ( $dbkey == '' ) {
3133                                                         # Can't have an empty self-link
3134                                                         return false;
3135                                                 }
3136                                                 $this->mInterwiki = '';
3137                                                 $firstPass = false;
3138                                                 # Do another namespace split...
3139                                                 continue;
3140                                         }
3141
3142                                         # If there's an initial colon after the interwiki, that also
3143                                         # resets the default namespace
3144                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3145                                                 $this->mNamespace = NS_MAIN;
3146                                                 $dbkey = substr( $dbkey, 1 );
3147                                         }
3148                                 }
3149                                 # If there's no recognized interwiki or namespace,
3150                                 # then let the colon expression be part of the title.
3151                         }
3152                         break;
3153                 } while ( true );
3154
3155                 # We already know that some pages won't be in the database!
3156                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3157                         $this->mArticleID = 0;
3158                 }
3159                 $fragment = strstr( $dbkey, '#' );
3160                 if ( false !== $fragment ) {
3161                         $this->setFragment( $fragment );
3162                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3163                         # remove whitespace again: prevents "Foo_bar_#"
3164                         # becoming "Foo_bar_"
3165                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3166                 }
3167
3168                 # Reject illegal characters.
3169                 $rxTc = self::getTitleInvalidRegex();
3170                 if ( preg_match( $rxTc, $dbkey ) ) {
3171                         return false;
3172                 }
3173
3174                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3175                 # reachable due to the way web browsers deal with 'relative' URLs.
3176                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3177                 if ( strpos( $dbkey, '.' ) !== false &&
3178                          ( $dbkey === '.' || $dbkey === '..' ||
3179                            strpos( $dbkey, './' ) === 0  ||
3180                            strpos( $dbkey, '../' ) === 0 ||
3181                            strpos( $dbkey, '/./' ) !== false ||
3182                            strpos( $dbkey, '/../' ) !== false  ||
3183                            substr( $dbkey, -2 ) == '/.' ||
3184                            substr( $dbkey, -3 ) == '/..' ) )
3185                 {
3186                         return false;
3187                 }
3188
3189                 # Magic tilde sequences? Nu-uh!
3190                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3191                         return false;
3192                 }
3193
3194                 # Limit the size of titles to 255 bytes. This is typically the size of the
3195                 # underlying database field. We make an exception for special pages, which
3196                 # don't need to be stored in the database, and may edge over 255 bytes due
3197                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3198                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3199                   strlen( $dbkey ) > 512 )
3200                 {
3201                         return false;
3202                 }
3203
3204                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3205                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3206                 # other site might be case-sensitive.
3207                 $this->mUserCaseDBKey = $dbkey;
3208                 if ( $this->mInterwiki == '' ) {
3209                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3210                 }
3211
3212                 # Can't make a link to a namespace alone... "empty" local links can only be
3213                 # self-links with a fragment identifier.
3214                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3215                         return false;
3216                 }
3217
3218                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3219                 // IP names are not allowed for accounts, and can only be referring to
3220                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3221                 // there are numerous ways to present the same IP. Having sp:contribs scan
3222                 // them all is silly and having some show the edits and others not is
3223                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3224                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3225                         ? IP::sanitizeIP( $dbkey )
3226                         : $dbkey;
3227
3228                 // Any remaining initial :s are illegal.
3229                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3230                         return false;
3231                 }
3232
3233                 # Fill fields
3234                 $this->mDbkeyform = $dbkey;
3235                 $this->mUrlform = wfUrlencode( $dbkey );
3236
3237                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3238
3239                 return true;
3240         }
3241
3242         /**
3243          * Get an array of Title objects linking to this Title
3244          * Also stores the IDs in the link cache.
3245          *
3246          * WARNING: do not use this function on arbitrary user-supplied titles!
3247          * On heavily-used templates it will max out the memory.
3248          *
3249          * @param $options Array: may be FOR UPDATE
3250          * @param $table String: table name
3251          * @param $prefix String: fields prefix
3252          * @return Array of Title objects linking here
3253          */
3254         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3255                 if ( count( $options ) > 0 ) {
3256                         $db = wfGetDB( DB_MASTER );
3257                 } else {
3258                         $db = wfGetDB( DB_SLAVE );
3259                 }
3260
3261                 $res = $db->select(
3262                         array( 'page', $table ),
3263                         self::getSelectFields(),
3264                         array(
3265                                 "{$prefix}_from=page_id",
3266                                 "{$prefix}_namespace" => $this->getNamespace(),
3267                                 "{$prefix}_title"     => $this->getDBkey() ),
3268                         __METHOD__,
3269                         $options
3270                 );
3271
3272                 $retVal = array();
3273                 if ( $res->numRows() ) {
3274                         $linkCache = LinkCache::singleton();
3275                         foreach ( $res as $row ) {
3276                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3277                                 if ( $titleObj ) {
3278                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3279                                         $retVal[] = $titleObj;
3280                                 }
3281                         }
3282                 }
3283                 return $retVal;
3284         }
3285
3286         /**
3287          * Get an array of Title objects using this Title as a template
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 $options Array: may be FOR UPDATE
3294          * @return Array of Title the Title objects linking here
3295          */
3296         public function getTemplateLinksTo( $options = array() ) {
3297                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3298         }
3299
3300         /**
3301          * Get an array of Title objects linked from this Title
3302          * Also stores the IDs in the link cache.
3303          *
3304          * WARNING: do not use this function on arbitrary user-supplied titles!
3305          * On heavily-used templates it will max out the memory.
3306          *
3307          * @param $options Array: may be FOR UPDATE
3308          * @param $table String: table name
3309          * @param $prefix String: fields prefix
3310          * @return Array of Title objects linking here
3311          */
3312         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3313                 global $wgContentHandlerUseDB;
3314
3315                 $id = $this->getArticleID();
3316
3317                 # If the page doesn't exist; there can't be any link from this page
3318                 if ( !$id ) {
3319                         return array();
3320                 }
3321
3322                 if ( count( $options ) > 0 ) {
3323                         $db = wfGetDB( DB_MASTER );
3324                 } else {
3325                         $db = wfGetDB( DB_SLAVE );
3326                 }
3327
3328                 $namespaceFiled = "{$prefix}_namespace";
3329                 $titleField = "{$prefix}_title";
3330
3331                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3332                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3333
3334                 $res = $db->select(
3335                         array( $table, 'page' ),
3336                         $fields,
3337                         array( "{$prefix}_from" => $id ),
3338                         __METHOD__,
3339                         $options,
3340                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3341                 );
3342
3343                 $retVal = array();
3344                 if ( $res->numRows() ) {
3345                         $linkCache = LinkCache::singleton();
3346                         foreach ( $res as $row ) {
3347                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3348                                 if ( $titleObj ) {
3349                                         if ( $row->page_id ) {
3350                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3351                                         } else {
3352                                                 $linkCache->addBadLinkObj( $titleObj );
3353                                         }
3354                                         $retVal[] = $titleObj;
3355                                 }
3356                         }
3357                 }
3358                 return $retVal;
3359         }
3360
3361         /**
3362          * Get an array of Title objects used on this Title as a template
3363          * Also stores the IDs in the link cache.
3364          *
3365          * WARNING: do not use this function on arbitrary user-supplied titles!
3366          * On heavily-used templates it will max out the memory.
3367          *
3368          * @param $options Array: may be FOR UPDATE
3369          * @return Array of Title the Title objects used here
3370          */
3371         public function getTemplateLinksFrom( $options = array() ) {
3372                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3373         }
3374
3375         /**
3376          * Get an array of Title objects referring to non-existent articles linked from this page
3377          *
3378          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3379          * @return Array of Title the Title objects
3380          */
3381         public function getBrokenLinksFrom() {
3382                 if ( $this->getArticleID() == 0 ) {
3383                         # All links from article ID 0 are false positives
3384                         return array();
3385                 }
3386
3387                 $dbr = wfGetDB( DB_SLAVE );
3388                 $res = $dbr->select(
3389                         array( 'page', 'pagelinks' ),
3390                         array( 'pl_namespace', 'pl_title' ),
3391                         array(
3392                                 'pl_from' => $this->getArticleID(),
3393                                 'page_namespace IS NULL'
3394                         ),
3395                         __METHOD__, array(),
3396                         array(
3397                                 'page' => array(
3398                                         'LEFT JOIN',
3399                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3400                                 )
3401                         )
3402                 );
3403
3404                 $retVal = array();
3405                 foreach ( $res as $row ) {
3406                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3407                 }
3408                 return $retVal;
3409         }
3410
3411
3412         /**
3413          * Get a list of URLs to purge from the Squid cache when this
3414          * page changes
3415          *
3416          * @return Array of String the URLs
3417          */
3418         public function getSquidURLs() {
3419                 $urls = array(
3420                         $this->getInternalURL(),
3421                         $this->getInternalURL( 'action=history' )
3422                 );
3423
3424                 $pageLang = $this->getPageLanguage();
3425                 if ( $pageLang->hasVariants() ) {
3426                         $variants = $pageLang->getVariants();
3427                         foreach ( $variants as $vCode ) {
3428                                 $urls[] = $this->getInternalURL( '', $vCode );
3429                         }
3430                 }
3431
3432                 return $urls;
3433         }
3434
3435         /**
3436          * Purge all applicable Squid URLs
3437          */
3438         public function purgeSquid() {
3439                 global $wgUseSquid;
3440                 if ( $wgUseSquid ) {
3441                         $urls = $this->getSquidURLs();
3442                         $u = new SquidUpdate( $urls );
3443                         $u->doUpdate();
3444                 }
3445         }
3446
3447         /**
3448          * Move this page without authentication
3449          *
3450          * @param $nt Title the new page Title
3451          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3452          */
3453         public function moveNoAuth( &$nt ) {
3454                 return $this->moveTo( $nt, false );
3455         }
3456
3457         /**
3458          * Check whether a given move operation would be valid.
3459          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3460          *
3461          * @param $nt Title the new title
3462          * @param $auth Bool indicates whether $wgUser's permissions
3463          *  should be checked
3464          * @param $reason String is the log summary of the move, used for spam checking
3465          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3466          */
3467         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3468                 global $wgUser, $wgContentHandlerUseDB;
3469
3470                 $errors = array();
3471                 if ( !$nt ) {
3472                         // Normally we'd add this to $errors, but we'll get
3473                         // lots of syntax errors if $nt is not an object
3474                         return array( array( 'badtitletext' ) );
3475                 }
3476                 if ( $this->equals( $nt ) ) {
3477                         $errors[] = array( 'selfmove' );
3478                 }
3479                 if ( !$this->isMovable() ) {
3480                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3481                 }
3482                 if ( $nt->getInterwiki() != '' ) {
3483                         $errors[] = array( 'immobile-target-namespace-iw' );
3484                 }
3485                 if ( !$nt->isMovable() ) {
3486                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3487                 }
3488
3489                 $oldid = $this->getArticleID();
3490                 $newid = $nt->getArticleID();
3491
3492                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3493                         $errors[] = array( 'articleexists' );
3494                 }
3495                 if ( ( $this->getDBkey() == '' ) ||
3496                          ( !$oldid ) ||
3497                          ( $nt->getDBkey() == '' ) ) {
3498                         $errors[] = array( 'badarticleerror' );
3499                 }
3500
3501                 // Content model checks
3502                 if ( !$wgContentHandlerUseDB &&
3503                                 $this->getContentModel() !== $nt->getContentModel() ) {
3504                         // can't move a page if that would change the page's content model
3505                         $errors[] = array( 'bad-target-model',
3506                                                         ContentHandler::getLocalizedName( $this->getContentModel() ),
3507                                                         ContentHandler::getLocalizedName( $nt->getContentModel() ) );
3508                 }
3509
3510                 // Image-specific checks
3511                 if ( $this->getNamespace() == NS_FILE ) {
3512                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3513                 }
3514
3515                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3516                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3517                 }
3518
3519                 if ( $auth ) {
3520                         $errors = wfMergeErrorArrays( $errors,
3521                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3522                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3523                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3524                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3525                 }
3526
3527                 $match = EditPage::matchSummarySpamRegex( $reason );
3528                 if ( $match !== false ) {
3529                         // This is kind of lame, won't display nice
3530                         $errors[] = array( 'spamprotectiontext' );
3531                 }
3532
3533                 $err = null;
3534                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3535                         $errors[] = array( 'hookaborted', $err );
3536                 }
3537
3538                 # The move is allowed only if (1) the target doesn't exist, or
3539                 # (2) the target is a redirect to the source, and has no history
3540                 # (so we can undo bad moves right after they're done).
3541
3542                 if ( 0 != $newid ) { # Target exists; check for validity
3543                         if ( !$this->isValidMoveTarget( $nt ) ) {
3544                                 $errors[] = array( 'articleexists' );
3545                         }
3546                 } else {
3547                         $tp = $nt->getTitleProtection();
3548                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3549                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3550                                 $errors[] = array( 'cantmove-titleprotected' );
3551                         }
3552                 }
3553                 if ( empty( $errors ) ) {
3554                         return true;
3555                 }
3556                 return $errors;
3557         }
3558
3559         /**
3560          * Check if the requested move target is a valid file move target
3561          * @param Title $nt Target title
3562          * @return array List of errors
3563          */
3564         protected function validateFileMoveOperation( $nt ) {
3565                 global $wgUser;
3566
3567                 $errors = array();
3568
3569                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3570
3571                 $file = wfLocalFile( $this );
3572                 if ( $file->exists() ) {
3573                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3574                                 $errors[] = array( 'imageinvalidfilename' );
3575                         }
3576                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3577                                 $errors[] = array( 'imagetypemismatch' );
3578                         }
3579                 }
3580
3581                 if ( $nt->getNamespace() != NS_FILE ) {
3582                         $errors[] = array( 'imagenocrossnamespace' );
3583                         // From here we want to do checks on a file object, so if we can't
3584                         // create one, we must return.
3585                         return $errors;
3586                 }
3587
3588                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3589
3590                 $destFile = wfLocalFile( $nt );
3591                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3592                         $errors[] = array( 'file-exists-sharedrepo' );
3593                 }
3594
3595                 return $errors;
3596         }
3597
3598         /**
3599          * Move a title to a new location
3600          *
3601          * @param $nt Title the new title
3602          * @param $auth Bool indicates whether $wgUser's permissions
3603          *  should be checked
3604          * @param $reason String the reason for the move
3605          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3606          *  Ignored if the user doesn't have the suppressredirect right.
3607          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3608          */
3609         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3610                 global $wgUser;
3611                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3612                 if ( is_array( $err ) ) {
3613                         // Auto-block user's IP if the account was "hard" blocked
3614                         $wgUser->spreadAnyEditBlock();
3615                         return $err;
3616                 }
3617                 // Check suppressredirect permission
3618                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3619                         $createRedirect = true;
3620                 }
3621
3622                 // If it is a file, move it first.
3623                 // It is done before all other moving stuff is done because it's hard to revert.
3624                 $dbw = wfGetDB( DB_MASTER );
3625                 if ( $this->getNamespace() == NS_FILE ) {
3626                         $file = wfLocalFile( $this );
3627                         if ( $file->exists() ) {
3628                                 $status = $file->move( $nt );
3629                                 if ( !$status->isOk() ) {
3630                                         return $status->getErrorsArray();
3631                                 }
3632                         }
3633                         // Clear RepoGroup process cache
3634                         RepoGroup::singleton()->clearCache( $this );
3635                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3636                 }
3637
3638                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3639                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3640                 $protected = $this->isProtected();
3641
3642                 // Do the actual move
3643                 $this->moveToInternal( $nt, $reason, $createRedirect );
3644
3645                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3646                 // cl_timestamp, which may disturb time-based lists on some sites.
3647                 $prefixes = $dbw->select(
3648                         'categorylinks',
3649                         array( 'cl_sortkey_prefix', 'cl_to' ),
3650                         array( 'cl_from' => $pageid ),
3651                         __METHOD__
3652                 );
3653                 foreach ( $prefixes as $prefixRow ) {
3654                         $prefix = $prefixRow->cl_sortkey_prefix;
3655                         $catTo = $prefixRow->cl_to;
3656                         $dbw->update( 'categorylinks',
3657                                 array(
3658                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3659                                                 $nt->getCategorySortkey( $prefix ) ),
3660                                         'cl_timestamp=cl_timestamp' ),
3661                                 array(
3662                                         'cl_from' => $pageid,
3663                                         'cl_to' => $catTo ),
3664                                 __METHOD__
3665                         );
3666                 }
3667
3668                 $redirid = $this->getArticleID();
3669
3670                 if ( $protected ) {
3671                         # Protect the redirect title as the title used to be...
3672                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3673                                 array(
3674                                         'pr_page'    => $redirid,
3675                                         'pr_type'    => 'pr_type',
3676                                         'pr_level'   => 'pr_level',
3677                                         'pr_cascade' => 'pr_cascade',
3678                                         'pr_user'    => 'pr_user',
3679                                         'pr_expiry'  => 'pr_expiry'
3680                                 ),
3681                                 array( 'pr_page' => $pageid ),
3682                                 __METHOD__,
3683                                 array( 'IGNORE' )
3684                         );
3685                         # Update the protection log
3686                         $log = new LogPage( 'protect' );
3687                         $comment = wfMessage(
3688                                 'prot_1movedto2',
3689                                 $this->getPrefixedText(),
3690                                 $nt->getPrefixedText()
3691                         )->inContentLanguage()->text();
3692                         if ( $reason ) {
3693                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3694                         }
3695                         // @todo FIXME: $params?
3696                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3697                 }
3698
3699                 # Update watchlists
3700                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3701                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3702                 $oldtitle = $this->getDBkey();
3703                 $newtitle = $nt->getDBkey();
3704
3705                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3706                         WatchedItem::duplicateEntries( $this, $nt );
3707                 }
3708
3709                 $dbw->commit( __METHOD__ );
3710
3711                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3712                 return true;
3713         }
3714
3715         /**
3716          * Move page to a title which is either a redirect to the
3717          * source page or nonexistent
3718          *
3719          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3720          * @param $reason String The reason for the move
3721          * @param $createRedirect Bool Whether to leave a redirect at the old title. Does not check
3722          *   if the user has the suppressredirect right
3723          * @throws MWException
3724          */
3725         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3726                 global $wgUser, $wgContLang;
3727
3728                 if ( $nt->exists() ) {
3729                         $moveOverRedirect = true;
3730                         $logType = 'move_redir';
3731                 } else {
3732                         $moveOverRedirect = false;
3733                         $logType = 'move';
3734                 }
3735
3736                 if ( $createRedirect ) {
3737                         $contentHandler = ContentHandler::getForTitle( $this );
3738                         $redirectContent = $contentHandler->makeRedirectContent( $nt );
3739
3740                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3741                 } else {
3742                         $redirectContent = null;
3743                 }
3744
3745                 $logEntry = new ManualLogEntry( 'move', $logType );
3746                 $logEntry->setPerformer( $wgUser );
3747                 $logEntry->setTarget( $this );
3748                 $logEntry->setComment( $reason );
3749                 $logEntry->setParameters( array(
3750                         '4::target' => $nt->getPrefixedText(),
3751                         '5::noredir' => $redirectContent ? '0': '1',
3752                 ) );
3753
3754                 $formatter = LogFormatter::newFromEntry( $logEntry );
3755                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3756                 $comment = $formatter->getPlainActionText();
3757                 if ( $reason ) {
3758                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3759                 }
3760                 # Truncate for whole multibyte characters.
3761                 $comment = $wgContLang->truncate( $comment, 255 );
3762
3763                 $oldid = $this->getArticleID();
3764
3765                 $dbw = wfGetDB( DB_MASTER );
3766
3767                 $newpage = WikiPage::factory( $nt );
3768
3769                 if ( $moveOverRedirect ) {
3770                         $newid = $nt->getArticleID();
3771
3772                         # Delete the old redirect. We don't save it to history since
3773                         # by definition if we've got here it's rather uninteresting.
3774                         # We have to remove it so that the next step doesn't trigger
3775                         # a conflict on the unique namespace+title index...
3776                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3777
3778                         $newpage->doDeleteUpdates( $newid );
3779                 }
3780
3781                 # Save a null revision in the page's history notifying of the move
3782                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3783                 if ( !is_object( $nullRevision ) ) {
3784                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3785                 }
3786
3787                 $nullRevision->insertOn( $dbw );
3788
3789                 # Change the name of the target page:
3790                 $dbw->update( 'page',
3791                         /* SET */ array(
3792                                 'page_namespace' => $nt->getNamespace(),
3793                                 'page_title'     => $nt->getDBkey(),
3794                         ),
3795                         /* WHERE */ array( 'page_id' => $oldid ),
3796                         __METHOD__
3797                 );
3798
3799                 $this->resetArticleID( 0 );
3800                 $nt->resetArticleID( $oldid );
3801
3802                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3803
3804                 wfRunHooks( 'NewRevisionFromEditComplete',
3805                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3806
3807                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3808
3809                 if ( !$moveOverRedirect ) {
3810                         WikiPage::onArticleCreate( $nt );
3811                 }
3812
3813                 # Recreate the redirect, this time in the other direction.
3814                 if ( !$redirectContent ) {
3815                         WikiPage::onArticleDelete( $this );
3816                 } else {
3817                         $redirectArticle = WikiPage::factory( $this );
3818                         $newid = $redirectArticle->insertOn( $dbw );
3819                         if ( $newid ) { // sanity
3820                                 $redirectRevision = new Revision( array(
3821                                         'title'   => $this, // for determining the default content model
3822                                         'page'    => $newid,
3823                                         'comment' => $comment,
3824                                         'content'    => $redirectContent ) );
3825                                 $redirectRevision->insertOn( $dbw );
3826                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3827
3828                                 wfRunHooks( 'NewRevisionFromEditComplete',
3829                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3830
3831                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3832                         }
3833                 }
3834
3835                 # Log the move
3836                 $logid = $logEntry->insert();
3837                 $logEntry->publish( $logid );
3838         }
3839
3840         /**
3841          * Move this page's subpages to be subpages of $nt
3842          *
3843          * @param $nt Title Move target
3844          * @param $auth bool Whether $wgUser's permissions should be checked
3845          * @param $reason string The reason for the move
3846          * @param $createRedirect bool Whether to create redirects from the old subpages to
3847          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3848          * @return mixed array with old page titles as keys, and strings (new page titles) or
3849          *     arrays (errors) as values, or an error array with numeric indices if no pages
3850          *     were moved
3851          */
3852         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3853                 global $wgMaximumMovedPages;
3854                 // Check permissions
3855                 if ( !$this->userCan( 'move-subpages' ) ) {
3856                         return array( 'cant-move-subpages' );
3857                 }
3858                 // Do the source and target namespaces support subpages?
3859                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3860                         return array( 'namespace-nosubpages',
3861                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3862                 }
3863                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3864                         return array( 'namespace-nosubpages',
3865                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3866                 }
3867
3868                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3869                 $retval = array();
3870                 $count = 0;
3871                 foreach ( $subpages as $oldSubpage ) {
3872                         $count++;
3873                         if ( $count > $wgMaximumMovedPages ) {
3874                                 $retval[$oldSubpage->getPrefixedTitle()] =
3875                                                 array( 'movepage-max-pages',
3876                                                         $wgMaximumMovedPages );
3877                                 break;
3878                         }
3879
3880                         // We don't know whether this function was called before
3881                         // or after moving the root page, so check both
3882                         // $this and $nt
3883                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3884                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3885                         {
3886                                 // When moving a page to a subpage of itself,
3887                                 // don't move it twice
3888                                 continue;
3889                         }
3890                         $newPageName = preg_replace(
3891                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3892                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3893                                         $oldSubpage->getDBkey() );
3894                         if ( $oldSubpage->isTalkPage() ) {
3895                                 $newNs = $nt->getTalkPage()->getNamespace();
3896                         } else {
3897                                 $newNs = $nt->getSubjectPage()->getNamespace();
3898                         }
3899                         # Bug 14385: we need makeTitleSafe because the new page names may
3900                         # be longer than 255 characters.
3901                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3902
3903                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3904                         if ( $success === true ) {
3905                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3906                         } else {
3907                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3908                         }
3909                 }
3910                 return $retval;
3911         }
3912
3913         /**
3914          * Checks if this page is just a one-rev redirect.
3915          * Adds lock, so don't use just for light purposes.
3916          *
3917          * @return Bool
3918          */
3919         public function isSingleRevRedirect() {
3920                 global $wgContentHandlerUseDB;
3921
3922                 $dbw = wfGetDB( DB_MASTER );
3923
3924                 # Is it a redirect?
3925                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3926                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3927
3928                 $row = $dbw->selectRow( 'page',
3929                         $fields,
3930                         $this->pageCond(),
3931                         __METHOD__,
3932                         array( 'FOR UPDATE' )
3933                 );
3934                 # Cache some fields we may want
3935                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3936                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3937                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3938                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
3939                 if ( !$this->mRedirect ) {
3940                         return false;
3941                 }
3942                 # Does the article have a history?
3943                 $row = $dbw->selectField( array( 'page', 'revision' ),
3944                         'rev_id',
3945                         array( 'page_namespace' => $this->getNamespace(),
3946                                 'page_title' => $this->getDBkey(),
3947                                 'page_id=rev_page',
3948                                 'page_latest != rev_id'
3949                         ),
3950                         __METHOD__,
3951                         array( 'FOR UPDATE' )
3952                 );
3953                 # Return true if there was no history
3954                 return ( $row === false );
3955         }
3956
3957         /**
3958          * Checks if $this can be moved to a given Title
3959          * - Selects for update, so don't call it unless you mean business
3960          *
3961          * @param $nt Title the new title to check
3962          * @return Bool
3963          */
3964         public function isValidMoveTarget( $nt ) {
3965                 # Is it an existing file?
3966                 if ( $nt->getNamespace() == NS_FILE ) {
3967                         $file = wfLocalFile( $nt );
3968                         if ( $file->exists() ) {
3969                                 wfDebug( __METHOD__ . ": file exists\n" );
3970                                 return false;
3971                         }
3972                 }
3973                 # Is it a redirect with no history?
3974                 if ( !$nt->isSingleRevRedirect() ) {
3975                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3976                         return false;
3977                 }
3978                 # Get the article text
3979                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3980                 if( !is_object( $rev ) ){
3981                         return false;
3982                 }
3983                 $content = $rev->getContent();
3984                 # Does the redirect point to the source?
3985                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3986                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3987
3988                 if ( $redirTitle ) {
3989                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3990                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3991                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3992                                 return false;
3993                         } else {
3994                                 return true;
3995                         }
3996                 } else {
3997                         # Fail safe (not a redirect after all. strange.)
3998                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3999                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4000                         return false;
4001                 }
4002         }
4003
4004         /**
4005          * Get categories to which this Title belongs and return an array of
4006          * categories' names.
4007          *
4008          * @return Array of parents in the form:
4009          *        $parent => $currentarticle
4010          */
4011         public function getParentCategories() {
4012                 global $wgContLang;
4013
4014                 $data = array();
4015
4016                 $titleKey = $this->getArticleID();
4017
4018                 if ( $titleKey === 0 ) {
4019                         return $data;
4020                 }
4021
4022                 $dbr = wfGetDB( DB_SLAVE );
4023
4024                 $res = $dbr->select( 'categorylinks', '*',
4025                         array(
4026                                 'cl_from' => $titleKey,
4027                         ),
4028                         __METHOD__,
4029                         array()
4030                 );
4031
4032                 if ( $dbr->numRows( $res ) > 0 ) {
4033                         foreach ( $res as $row ) {
4034                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
4035                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4036                         }
4037                 }
4038                 return $data;
4039         }
4040
4041         /**
4042          * Get a tree of parent categories
4043          *
4044          * @param $children Array with the children in the keys, to check for circular refs
4045          * @return Array Tree of parent categories
4046          */
4047         public function getParentCategoryTree( $children = array() ) {
4048                 $stack = array();
4049                 $parents = $this->getParentCategories();
4050
4051                 if ( $parents ) {
4052                         foreach ( $parents as $parent => $current ) {
4053                                 if ( array_key_exists( $parent, $children ) ) {
4054                                         # Circular reference
4055                                         $stack[$parent] = array();
4056                                 } else {
4057                                         $nt = Title::newFromText( $parent );
4058                                         if ( $nt ) {
4059                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4060                                         }
4061                                 }
4062                         }
4063                 }
4064
4065                 return $stack;
4066         }
4067
4068         /**
4069          * Get an associative array for selecting this title from
4070          * the "page" table
4071          *
4072          * @return Array suitable for the $where parameter of DB::select()
4073          */
4074         public function pageCond() {
4075                 if ( $this->mArticleID > 0 ) {
4076                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4077                         return array( 'page_id' => $this->mArticleID );
4078                 } else {
4079                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4080                 }
4081         }
4082
4083         /**
4084          * Get the revision ID of the previous revision
4085          *
4086          * @param $revId Int Revision ID. Get the revision that was before this one.
4087          * @param $flags Int Title::GAID_FOR_UPDATE
4088          * @return Int|Bool Old revision ID, or FALSE if none exists
4089          */
4090         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4091                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4092                 $revId = $db->selectField( 'revision', 'rev_id',
4093                         array(
4094                                 'rev_page' => $this->getArticleID( $flags ),
4095                                 'rev_id < ' . intval( $revId )
4096                         ),
4097                         __METHOD__,
4098                         array( 'ORDER BY' => 'rev_id DESC' )
4099                 );
4100
4101                 if ( $revId === false ) {
4102                         return false;
4103                 } else {
4104                         return intval( $revId );
4105                 }
4106         }
4107
4108         /**
4109          * Get the revision ID of the next revision
4110          *
4111          * @param $revId Int Revision ID. Get the revision that was after this one.
4112          * @param $flags Int Title::GAID_FOR_UPDATE
4113          * @return Int|Bool Next revision ID, or FALSE if none exists
4114          */
4115         public function getNextRevisionID( $revId, $flags = 0 ) {
4116                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4117                 $revId = $db->selectField( 'revision', 'rev_id',
4118                         array(
4119                                 'rev_page' => $this->getArticleID( $flags ),
4120                                 'rev_id > ' . intval( $revId )
4121                         ),
4122                         __METHOD__,
4123                         array( 'ORDER BY' => 'rev_id' )
4124                 );
4125
4126                 if ( $revId === false ) {
4127                         return false;
4128                 } else {
4129                         return intval( $revId );
4130                 }
4131         }
4132
4133         /**
4134          * Get the first revision of the page
4135          *
4136          * @param $flags Int Title::GAID_FOR_UPDATE
4137          * @return Revision|Null if page doesn't exist
4138          */
4139         public function getFirstRevision( $flags = 0 ) {
4140                 $pageId = $this->getArticleID( $flags );
4141                 if ( $pageId ) {
4142                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4143                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4144                                 array( 'rev_page' => $pageId ),
4145                                 __METHOD__,
4146                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4147                         );
4148                         if ( $row ) {
4149                                 return new Revision( $row );
4150                         }
4151                 }
4152                 return null;
4153         }
4154
4155         /**
4156          * Get the oldest revision timestamp of this page
4157          *
4158          * @param $flags Int Title::GAID_FOR_UPDATE
4159          * @return String: MW timestamp
4160          */
4161         public function getEarliestRevTime( $flags = 0 ) {
4162                 $rev = $this->getFirstRevision( $flags );
4163                 return $rev ? $rev->getTimestamp() : null;
4164         }
4165
4166         /**
4167          * Check if this is a new page
4168          *
4169          * @return bool
4170          */
4171         public function isNewPage() {
4172                 $dbr = wfGetDB( DB_SLAVE );
4173                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4174         }
4175
4176         /**
4177          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4178          *
4179          * @return bool
4180          */
4181         public function isBigDeletion() {
4182                 global $wgDeleteRevisionsLimit;
4183
4184                 if ( !$wgDeleteRevisionsLimit ) {
4185                         return false;
4186                 }
4187
4188                 $revCount = $this->estimateRevisionCount();
4189                 return $revCount > $wgDeleteRevisionsLimit;
4190         }
4191
4192         /**
4193          * Get the  approximate revision count of this page.
4194          *
4195          * @return int
4196          */
4197         public function estimateRevisionCount() {
4198                 if ( !$this->exists() ) {
4199                         return 0;
4200                 }
4201
4202                 if ( $this->mEstimateRevisions === null ) {
4203                         $dbr = wfGetDB( DB_SLAVE );
4204                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4205                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4206                 }
4207
4208                 return $this->mEstimateRevisions;
4209         }
4210
4211         /**
4212          * Get the number of revisions between the given revision.
4213          * Used for diffs and other things that really need it.
4214          *
4215          * @param $old int|Revision Old revision or rev ID (first before range)
4216          * @param $new int|Revision New revision or rev ID (first after range)
4217          * @return Int Number of revisions between these revisions.
4218          */
4219         public function countRevisionsBetween( $old, $new ) {
4220                 if ( !( $old instanceof Revision ) ) {
4221                         $old = Revision::newFromTitle( $this, (int)$old );
4222                 }
4223                 if ( !( $new instanceof Revision ) ) {
4224                         $new = Revision::newFromTitle( $this, (int)$new );
4225                 }
4226                 if ( !$old || !$new ) {
4227                         return 0; // nothing to compare
4228                 }
4229                 $dbr = wfGetDB( DB_SLAVE );
4230                 return (int)$dbr->selectField( 'revision', 'count(*)',
4231                         array(
4232                                 'rev_page' => $this->getArticleID(),
4233                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4234                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4235                         ),
4236                         __METHOD__
4237                 );
4238         }
4239
4240         /**
4241          * Get the number of authors between the given revisions or revision IDs.
4242          * Used for diffs and other things that really need it.
4243          *
4244          * @param $old int|Revision Old revision or rev ID (first before range by default)
4245          * @param $new int|Revision New revision or rev ID (first after range by default)
4246          * @param $limit int Maximum number of authors
4247          * @param $options string|array (Optional): Single option, or an array of options:
4248          *     'include_old' Include $old in the range; $new is excluded.
4249          *     'include_new' Include $new in the range; $old is excluded.
4250          *     'include_both' Include both $old and $new in the range.
4251          *     Unknown option values are ignored.
4252          * @return int Number of revision authors in the range; zero if not both revisions exist
4253          */
4254         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4255                 if ( !( $old instanceof Revision ) ) {
4256                         $old = Revision::newFromTitle( $this, (int)$old );
4257                 }
4258                 if ( !( $new instanceof Revision ) ) {
4259                         $new = Revision::newFromTitle( $this, (int)$new );
4260                 }
4261                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4262                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4263                 // in the sanity check below?
4264                 if ( !$old || !$new ) {
4265                         return 0; // nothing to compare
4266                 }
4267                 $old_cmp = '>';
4268                 $new_cmp = '<';
4269                 $options = (array) $options;
4270                 if ( in_array( 'include_old', $options ) ) {
4271                         $old_cmp = '>=';
4272                 }
4273                 if ( in_array( 'include_new', $options ) ) {
4274                         $new_cmp = '<=';
4275                 }
4276                 if ( in_array( 'include_both', $options ) ) {
4277                         $old_cmp = '>=';
4278                         $new_cmp = '<=';
4279                 }
4280                 // No DB query needed if $old and $new are the same or successive revisions:
4281                 if ( $old->getId() === $new->getId() ) {
4282                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4283                 } else if ( $old->getId() === $new->getParentId() ) {
4284                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4285                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4286                         }
4287                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4288                 }
4289                 $dbr = wfGetDB( DB_SLAVE );
4290                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4291                         array(
4292                                 'rev_page' => $this->getArticleID(),
4293                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4294                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4295                         ), __METHOD__,
4296                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4297                 );
4298                 return (int)$dbr->numRows( $res );
4299         }
4300
4301         /**
4302          * Compare with another title.
4303          *
4304          * @param $title Title
4305          * @return Bool
4306          */
4307         public function equals( Title $title ) {
4308                 // Note: === is necessary for proper matching of number-like titles.
4309                 return $this->getInterwiki() === $title->getInterwiki()
4310                         && $this->getNamespace() == $title->getNamespace()
4311                         && $this->getDBkey() === $title->getDBkey();
4312         }
4313
4314         /**
4315          * Check if this title is a subpage of another title
4316          *
4317          * @param $title Title
4318          * @return Bool
4319          */
4320         public function isSubpageOf( Title $title ) {
4321                 return $this->getInterwiki() === $title->getInterwiki()
4322                         && $this->getNamespace() == $title->getNamespace()
4323                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4324         }
4325
4326         /**
4327          * Check if page exists.  For historical reasons, this function simply
4328          * checks for the existence of the title in the page table, and will
4329          * thus return false for interwiki links, special pages and the like.
4330          * If you want to know if a title can be meaningfully viewed, you should
4331          * probably call the isKnown() method instead.
4332          *
4333          * @return Bool
4334          */
4335         public function exists() {
4336                 return $this->getArticleID() != 0;
4337         }
4338
4339         /**
4340          * Should links to this title be shown as potentially viewable (i.e. as
4341          * "bluelinks"), even if there's no record by this title in the page
4342          * table?
4343          *
4344          * This function is semi-deprecated for public use, as well as somewhat
4345          * misleadingly named.  You probably just want to call isKnown(), which
4346          * calls this function internally.
4347          *
4348          * (ISSUE: Most of these checks are cheap, but the file existence check
4349          * can potentially be quite expensive.  Including it here fixes a lot of
4350          * existing code, but we might want to add an optional parameter to skip
4351          * it and any other expensive checks.)
4352          *
4353          * @return Bool
4354          */
4355         public function isAlwaysKnown() {
4356                 $isKnown = null;
4357
4358                 /**
4359                  * Allows overriding default behaviour for determining if a page exists.
4360                  * If $isKnown is kept as null, regular checks happen. If it's
4361                  * a boolean, this value is returned by the isKnown method.
4362                  *
4363                  * @since 1.20
4364                  *
4365                  * @param Title $title
4366                  * @param boolean|null $isKnown
4367                  */
4368                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4369
4370                 if ( !is_null( $isKnown ) ) {
4371                         return $isKnown;
4372                 }
4373
4374                 if ( $this->mInterwiki != '' ) {
4375                         return true;  // any interwiki link might be viewable, for all we know
4376                 }
4377
4378                 switch( $this->mNamespace ) {
4379                         case NS_MEDIA:
4380                         case NS_FILE:
4381                                 // file exists, possibly in a foreign repo
4382                                 return (bool)wfFindFile( $this );
4383                         case NS_SPECIAL:
4384                                 // valid special page
4385                                 return SpecialPageFactory::exists( $this->getDBkey() );
4386                         case NS_MAIN:
4387                                 // selflink, possibly with fragment
4388                                 return $this->mDbkeyform == '';
4389                         case NS_MEDIAWIKI:
4390                                 // known system message
4391                                 return $this->hasSourceText() !== false;
4392                         default:
4393                                 return false;
4394                 }
4395         }
4396
4397         /**
4398          * Does this title refer to a page that can (or might) be meaningfully
4399          * viewed?  In particular, this function may be used to determine if
4400          * links to the title should be rendered as "bluelinks" (as opposed to
4401          * "redlinks" to non-existent pages).
4402          * Adding something else to this function will cause inconsistency
4403          * since LinkHolderArray calls isAlwaysKnown() and does its own
4404          * page existence check.
4405          *
4406          * @return Bool
4407          */
4408         public function isKnown() {
4409                 return $this->isAlwaysKnown() || $this->exists();
4410         }
4411
4412         /**
4413          * Does this page have source text?
4414          *
4415          * @return Boolean
4416          */
4417         public function hasSourceText() {
4418                 if ( $this->exists() ) {
4419                         return true;
4420                 }
4421
4422                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4423                         // If the page doesn't exist but is a known system message, default
4424                         // message content will be displayed, same for language subpages-
4425                         // Use always content language to avoid loading hundreds of languages
4426                         // to get the link color.
4427                         global $wgContLang;
4428                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4429                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4430                         return $message->exists();
4431                 }
4432
4433                 return false;
4434         }
4435
4436         /**
4437          * Get the default message text or false if the message doesn't exist
4438          *
4439          * @return String or false
4440          */
4441         public function getDefaultMessageText() {
4442                 global $wgContLang;
4443
4444                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4445                         return false;
4446                 }
4447
4448                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4449                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4450
4451                 if ( $message->exists() ) {
4452                         return $message->plain();
4453                 } else {
4454                         return false;
4455                 }
4456         }
4457
4458         /**
4459          * Updates page_touched for this page; called from LinksUpdate.php
4460          *
4461          * @return Bool true if the update succeded
4462          */
4463         public function invalidateCache() {
4464                 if ( wfReadOnly() ) {
4465                         return false;
4466                 }
4467                 $dbw = wfGetDB( DB_MASTER );
4468                 $success = $dbw->update(
4469                         'page',
4470                         array( 'page_touched' => $dbw->timestamp() ),
4471                         $this->pageCond(),
4472                         __METHOD__
4473                 );
4474                 HTMLFileCache::clearFileCache( $this );
4475                 return $success;
4476         }
4477
4478         /**
4479          * Update page_touched timestamps and send squid purge messages for
4480          * pages linking to this title. May be sent to the job queue depending
4481          * on the number of links. Typically called on create and delete.
4482          */
4483         public function touchLinks() {
4484                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4485                 $u->doUpdate();
4486
4487                 if ( $this->getNamespace() == NS_CATEGORY ) {
4488                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4489                         $u->doUpdate();
4490                 }
4491         }
4492
4493         /**
4494          * Get the last touched timestamp
4495          *
4496          * @param $db DatabaseBase: optional db
4497          * @return String last-touched timestamp
4498          */
4499         public function getTouched( $db = null ) {
4500                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4501                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4502                 return $touched;
4503         }
4504
4505         /**
4506          * Get the timestamp when this page was updated since the user last saw it.
4507          *
4508          * @param $user User
4509          * @return String|Null
4510          */
4511         public function getNotificationTimestamp( $user = null ) {
4512                 global $wgUser, $wgShowUpdatedMarker;
4513                 // Assume current user if none given
4514                 if ( !$user ) {
4515                         $user = $wgUser;
4516                 }
4517                 // Check cache first
4518                 $uid = $user->getId();
4519                 // avoid isset here, as it'll return false for null entries
4520                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4521                         return $this->mNotificationTimestamp[$uid];
4522                 }
4523                 if ( !$uid || !$wgShowUpdatedMarker ) {
4524                         return $this->mNotificationTimestamp[$uid] = false;
4525                 }
4526                 // Don't cache too much!
4527                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4528                         $this->mNotificationTimestamp = array();
4529                 }
4530                 $dbr = wfGetDB( DB_SLAVE );
4531                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4532                         'wl_notificationtimestamp',
4533                         array(
4534                                 'wl_user' => $user->getId(),
4535                                 'wl_namespace' => $this->getNamespace(),
4536                                 'wl_title' => $this->getDBkey(),
4537                         ),
4538                         __METHOD__
4539                 );
4540                 return $this->mNotificationTimestamp[$uid];
4541         }
4542
4543         /**
4544          * Generate strings used for xml 'id' names in monobook tabs
4545          *
4546          * @param $prepend string defaults to 'nstab-'
4547          * @return String XML 'id' name
4548          */
4549         public function getNamespaceKey( $prepend = 'nstab-' ) {
4550                 global $wgContLang;
4551                 // Gets the subject namespace if this title
4552                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4553                 // Checks if cononical namespace name exists for namespace
4554                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4555                         // Uses canonical namespace name
4556                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4557                 } else {
4558                         // Uses text of namespace
4559                         $namespaceKey = $this->getSubjectNsText();
4560                 }
4561                 // Makes namespace key lowercase
4562                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4563                 // Uses main
4564                 if ( $namespaceKey == '' ) {
4565                         $namespaceKey = 'main';
4566                 }
4567                 // Changes file to image for backwards compatibility
4568                 if ( $namespaceKey == 'file' ) {
4569                         $namespaceKey = 'image';
4570                 }
4571                 return $prepend . $namespaceKey;
4572         }
4573
4574         /**
4575          * Get all extant redirects to this Title
4576          *
4577          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4578          * @return Array of Title redirects to this title
4579          */
4580         public function getRedirectsHere( $ns = null ) {
4581                 $redirs = array();
4582
4583                 $dbr = wfGetDB( DB_SLAVE );
4584                 $where = array(
4585                         'rd_namespace' => $this->getNamespace(),
4586                         'rd_title' => $this->getDBkey(),
4587                         'rd_from = page_id'
4588                 );
4589                 if ( $this->isExternal() ) {
4590                         $where['rd_interwiki'] = $this->getInterwiki();
4591                 } else {
4592                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4593                 }
4594                 if ( !is_null( $ns ) ) {
4595                         $where['page_namespace'] = $ns;
4596                 }
4597
4598                 $res = $dbr->select(
4599                         array( 'redirect', 'page' ),
4600                         array( 'page_namespace', 'page_title' ),
4601                         $where,
4602                         __METHOD__
4603                 );
4604
4605                 foreach ( $res as $row ) {
4606                         $redirs[] = self::newFromRow( $row );
4607                 }
4608                 return $redirs;
4609         }
4610
4611         /**
4612          * Check if this Title is a valid redirect target
4613          *
4614          * @return Bool
4615          */
4616         public function isValidRedirectTarget() {
4617                 global $wgInvalidRedirectTargets;
4618
4619                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4620                 if ( $this->isSpecial( 'Userlogout' ) ) {
4621                         return false;
4622                 }
4623
4624                 foreach ( $wgInvalidRedirectTargets as $target ) {
4625                         if ( $this->isSpecial( $target ) ) {
4626                                 return false;
4627                         }
4628                 }
4629
4630                 return true;
4631         }
4632
4633         /**
4634          * Get a backlink cache object
4635          *
4636          * @return BacklinkCache
4637          */
4638         public function getBacklinkCache() {
4639                 return BacklinkCache::get( $this );
4640         }
4641
4642         /**
4643          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4644          *
4645          * @return Boolean
4646          */
4647         public function canUseNoindex() {
4648                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4649
4650                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4651                         ? $wgContentNamespaces
4652                         : $wgExemptFromUserRobotsControl;
4653
4654                 return !in_array( $this->mNamespace, $bannedNamespaces );
4655
4656         }
4657
4658         /**
4659          * Returns the raw sort key to be used for categories, with the specified
4660          * prefix.  This will be fed to Collation::getSortKey() to get a
4661          * binary sortkey that can be used for actual sorting.
4662          *
4663          * @param $prefix string The prefix to be used, specified using
4664          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4665          *   prefix.
4666          * @return string
4667          */
4668         public function getCategorySortkey( $prefix = '' ) {
4669                 $unprefixed = $this->getText();
4670
4671                 // Anything that uses this hook should only depend
4672                 // on the Title object passed in, and should probably
4673                 // tell the users to run updateCollations.php --force
4674                 // in order to re-sort existing category relations.
4675                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4676                 if ( $prefix !== '' ) {
4677                         # Separate with a line feed, so the unprefixed part is only used as
4678                         # a tiebreaker when two pages have the exact same prefix.
4679                         # In UCA, tab is the only character that can sort above LF
4680                         # so we strip both of them from the original prefix.
4681                         $prefix = strtr( $prefix, "\n\t", '  ' );
4682                         return "$prefix\n$unprefixed";
4683                 }
4684                 return $unprefixed;
4685         }
4686
4687         /**
4688          * Get the language in which the content of this page is written in
4689          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4690          * e.g. $wgLang (such as special pages, which are in the user language).
4691          *
4692          * @since 1.18
4693          * @return Language
4694          */
4695         public function getPageLanguage() {
4696                 global $wgLang;
4697                 if ( $this->isSpecialPage() ) {
4698                         // special pages are in the user language
4699                         return $wgLang;
4700                 }
4701
4702                 //TODO: use the LinkCache to cache this! Note that this may depend on user settings, so the cache should be only per-request.
4703                 //NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4704                 $contentHandler = ContentHandler::getForTitle( $this );
4705                 $pageLang = $contentHandler->getPageLanguage( $this );
4706
4707                 return wfGetLangObj( $pageLang );
4708         }
4709
4710         /**
4711          * Get the language in which the content of this page is written when
4712          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4713          * e.g. $wgLang (such as special pages, which are in the user language).
4714          *
4715          * @since 1.20
4716          * @return Language
4717          */
4718         public function getPageViewLanguage() {
4719                 global $wgLang;
4720
4721                 if ( $this->isSpecialPage() ) {
4722                         // If the user chooses a variant, the content is actually
4723                         // in a language whose code is the variant code.
4724                         $variant = $wgLang->getPreferredVariant();
4725                         if ( $wgLang->getCode() !== $variant ) {
4726                                 return Language::factory( $variant );
4727                         }
4728
4729                         return $wgLang;
4730                 }
4731
4732                 //NOTE: can't be cached persistently, depends on user settings
4733                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4734                 $contentHandler = ContentHandler::getForTitle( $this );
4735                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4736                 return $pageLang;
4737         }
4738
4739         /**
4740          * Get a list of rendered edit notices for this page.
4741          *
4742          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4743          * they will already be wrapped in paragraphs.
4744          *
4745          * @since 1.21
4746          * @return Array
4747          */
4748         public function getEditNotices() {
4749                 $notices = array();
4750
4751                 # Optional notices on a per-namespace and per-page basis
4752                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4753                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4754                 if ( $editnotice_ns_message->exists() ) {
4755                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4756                 }
4757                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4758                         $parts = explode( '/', $this->getDBkey() );
4759                         $editnotice_base = $editnotice_ns;
4760                         while ( count( $parts ) > 0 ) {
4761                                 $editnotice_base .= '-' . array_shift( $parts );
4762                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4763                                 if ( $editnotice_base_msg->exists() ) {
4764                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4765                                 }
4766                         }
4767                 } else {
4768                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4769                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4770                         $editnoticeMsg = wfMessage( $editnoticeText );
4771                         if ( $editnoticeMsg->exists() ) {
4772                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4773                         }
4774                 }
4775                 return $notices;
4776         }
4777 }