includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @todo:  determine if it is really necessary to load this.  Appears to be left over from pre-autoloader versions, and
   9  *   is only really needed to provide access to constant UTF8_REPLACEMENT, which actually resides in UtfNormalDefines.php
  10  *   and is loaded by UtfNormalUtil.php, which is loaded by UtfNormal.php.
  11  */
  12 if ( !class_exists( 'UtfNormal' ) ) {
  13         require_once( dirname( __FILE__ ) . '/normal/UtfNormal.php' );
  14 }
  15
  16 /**
  17  * Represents a title within MediaWiki.
  18  * Optionally may contain an interwiki designation or namespace.
  19  * @note This class can fetch various kinds of data from the database;
  20  *       however, it does so inefficiently.
  21  *
  22  * @internal documentation reviewed 15 Mar 2010
  23  */
  24 class Title {
  25         /** @name Static cache variables */
  26         // @{
  27         static private $titleCache = array();
  28         // @}
  29
  30         /**
  31          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  32          * commonly used titles. On a batch operation this can become a memory leak
  33          * if not bounded. After hitting this many titles reset the cache.
  34          */
  35         const CACHE_MAX = 1000;
  36
  37         /**
  38          * Used to be GAID_FOR_UPDATE define. Used with getArticleId() and friends
  39          * to use the master DB
  40          */
  41         const GAID_FOR_UPDATE = 1;
  42
  43
  44         /**
  45          * @name Private member variables
  46          * Please use the accessor functions instead.
  47          * @private
  48          */
  49         // @{
  50
  51         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  52         var $mUrlform = '';               // /< URL-encoded form of the main part
  53         var $mDbkeyform = '';             // /< Main part with underscores
  54         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  55         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  56         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  57         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  58         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  59         var $mLatestID = false;           // /< ID of most recent revision
  60         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  61         var $mOldRestrictions = false;
  62         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  63         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  64         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  65         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  66         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  67         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  68         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  69         var $mTitleProtection;            ///< Cached value of getTitleProtection
  70         # Don't change the following default, NS_MAIN is hardcoded in several
  71         # places.  See bug 696.
  72         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  73                                           # Zero except in {{transclusion}} tags
  74         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  75         var $mLength = -1;                // /< The page length, 0 for special pages
  76         var $mRedirect = null;            // /< Is the article at this title a redirect?
  77         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  78         var $mBacklinkCache = null;       // /< Cache of links to this title
  79         // @}
  80
  81
  82         /**
  83          * Constructor
  84          * @private
  85          */
  86         /* private */ function __construct() { }
  87
  88         /**
  89          * Create a new Title from a prefixed DB key
  90          *
  91          * @param $key \type{\string} The database key, which has underscores
  92          *      instead of spaces, possibly including namespace and
  93          *      interwiki prefixes
  94          * @return \type{Title} the new object, or NULL on an error
  95          */
  96         public static function newFromDBkey( $key ) {
  97                 $t = new Title();
  98                 $t->mDbkeyform = $key;
  99                 if ( $t->secureAndSplit() ) {
 100                         return $t;
 101                 } else {
 102                         return null;
 103                 }
 104         }
 105
 106         /**
 107          * Create a new Title from text, such as what one would find in a link. De-
 108          * codes any HTML entities in the text.
 109          *
 110          * @param $text string  The link text; spaces, prefixes, and an
 111          *   initial ':' indicating the main namespace are accepted.
 112          * @param $defaultNamespace int The namespace to use if none is speci-
 113          *   fied by a prefix.  If you want to force a specific namespace even if
 114          *   $text might begin with a namespace prefix, use makeTitle() or
 115          *   makeTitleSafe().
 116          * @return Title  The new object, or null on an error.
 117          */
 118         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 119                 if ( is_object( $text ) ) {
 120                         throw new MWException( 'Title::newFromText given an object' );
 121                 }
 122
 123                 /**
 124                  * Wiki pages often contain multiple links to the same page.
 125                  * Title normalization and parsing can become expensive on
 126                  * pages with many links, so we can save a little time by
 127                  * caching them.
 128                  *
 129                  * In theory these are value objects and won't get changed...
 130                  */
 131                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 132                         return Title::$titleCache[$text];
 133                 }
 134
 135                 /**
 136                  * Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 137                  */
 138                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 139
 140                 $t = new Title();
 141                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 142                 $t->mDefaultNamespace = $defaultNamespace;
 143
 144                 static $cachedcount = 0 ;
 145                 if ( $t->secureAndSplit() ) {
 146                         if ( $defaultNamespace == NS_MAIN ) {
 147                                 if ( $cachedcount >= self::CACHE_MAX ) {
 148                                         # Avoid memory leaks on mass operations...
 149                                         Title::$titleCache = array();
 150                                         $cachedcount = 0;
 151                                 }
 152                                 $cachedcount++;
 153                                 Title::$titleCache[$text] =& $t;
 154                         }
 155                         return $t;
 156                 } else {
 157                         $ret = null;
 158                         return $ret;
 159                 }
 160         }
 161
 162         /**
 163          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 164          *
 165          * Example of wrong and broken code:
 166          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 167          *
 168          * Example of right code:
 169          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 170          *
 171          * Create a new Title from URL-encoded text. Ensures that
 172          * the given title's length does not exceed the maximum.
 173          *
 174          * @param $url \type{\string} the title, as might be taken from a URL
 175          * @return \type{Title} the new object, or NULL on an error
 176          */
 177         public static function newFromURL( $url ) {
 178                 global $wgLegalTitleChars;
 179                 $t = new Title();
 180
 181                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 182                 # but some URLs used it as a space replacement and they still come
 183                 # from some external search tools.
 184                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 185                         $url = str_replace( '+', ' ', $url );
 186                 }
 187
 188                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 189                 if ( $t->secureAndSplit() ) {
 190                         return $t;
 191                 } else {
 192                         return null;
 193                 }
 194         }
 195
 196         /**
 197          * Create a new Title from an article ID
 198          *
 199          * @param $id \type{\int} the page_id corresponding to the Title to create
 200          * @param $flags \type{\int} use Title::GAID_FOR_UPDATE to use master
 201          * @return \type{Title} the new object, or NULL on an error
 202          */
 203         public static function newFromID( $id, $flags = 0 ) {
 204                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 205                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 206                 if ( $row !== false ) {
 207                         $title = Title::newFromRow( $row );
 208                 } else {
 209                         $title = null;
 210                 }
 211                 return $title;
 212         }
 213
 214         /**
 215          * Make an array of titles from an array of IDs
 216          *
 217          * @param $ids \type{\arrayof{\int}} Array of IDs
 218          * @return \type{\arrayof{Title}} Array of Titles
 219          */
 220         public static function newFromIDs( $ids ) {
 221                 if ( !count( $ids ) ) {
 222                         return array();
 223                 }
 224                 $dbr = wfGetDB( DB_SLAVE );
 225
 226                 $res = $dbr->select(
 227                         'page',
 228                         array(
 229                                 'page_namespace', 'page_title', 'page_id',
 230                                 'page_len', 'page_is_redirect', 'page_latest',
 231                         ),
 232                         array( 'page_id' => $ids ),
 233                         __METHOD__
 234                 );
 235
 236                 $titles = array();
 237                 foreach ( $res as $row ) {
 238                         $titles[] = Title::newFromRow( $row );
 239                 }
 240                 return $titles;
 241         }
 242
 243         /**
 244          * Make a Title object from a DB row
 245          *
 246          * @param $row \type{Row} (needs at least page_title,page_namespace)
 247          * @return \type{Title} corresponding Title
 248          */
 249         public static function newFromRow( $row ) {
 250                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 251
 252                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 253                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 254                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 255                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 256
 257                 return $t;
 258         }
 259
 260         /**
 261          * Create a new Title from a namespace index and a DB key.
 262          * It's assumed that $ns and $title are *valid*, for instance when
 263          * they came directly from the database or a special page name.
 264          * For convenience, spaces are converted to underscores so that
 265          * eg user_text fields can be used directly.
 266          *
 267          * @param $ns \type{\int} the namespace of the article
 268          * @param $title \type{\string} the unprefixed database key form
 269          * @param $fragment \type{\string} The link fragment (after the "#")
 270          * @param $interwiki \type{\string} The interwiki prefix
 271          * @return \type{Title} the new object
 272          */
 273         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 274                 $t = new Title();
 275                 $t->mInterwiki = $interwiki;
 276                 $t->mFragment = $fragment;
 277                 $t->mNamespace = $ns = intval( $ns );
 278                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 279                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 280                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 281                 $t->mTextform = str_replace( '_', ' ', $title );
 282                 return $t;
 283         }
 284
 285         /**
 286          * Create a new Title from a namespace index and a DB key.
 287          * The parameters will be checked for validity, which is a bit slower
 288          * than makeTitle() but safer for user-provided data.
 289          *
 290          * @param $ns \type{\int} the namespace of the article
 291          * @param $title \type{\string} the database key form
 292          * @param $fragment \type{\string} The link fragment (after the "#")
 293          * @param $interwiki \type{\string} The interwiki prefix
 294          * @return \type{Title} the new object, or NULL on an error
 295          */
 296         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 297                 $t = new Title();
 298                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 299                 if ( $t->secureAndSplit() ) {
 300                         return $t;
 301                 } else {
 302                         return null;
 303                 }
 304         }
 305
 306         /**
 307          * Create a new Title for the Main Page
 308          *
 309          * @return \type{Title} the new object
 310          */
 311         public static function newMainPage() {
 312                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 313                 // Don't give fatal errors if the message is broken
 314                 if ( !$title ) {
 315                         $title = Title::newFromText( 'Main Page' );
 316                 }
 317                 return $title;
 318         }
 319
 320         /**
 321          * Extract a redirect destination from a string and return the
 322          * Title, or null if the text doesn't contain a valid redirect
 323          * This will only return the very next target, useful for
 324          * the redirect table and other checks that don't need full recursion
 325          *
 326          * @param $text \type{\string} Text with possible redirect
 327          * @return \type{Title} The corresponding Title
 328          */
 329         public static function newFromRedirect( $text ) {
 330                 return self::newFromRedirectInternal( $text );
 331         }
 332
 333         /**
 334          * Extract a redirect destination from a string and return the
 335          * Title, or null if the text doesn't contain a valid redirect
 336          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 337          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 338          *
 339          * @param $text \type{\string} Text with possible redirect
 340          * @return \type{Title} The corresponding Title
 341          */
 342         public static function newFromRedirectRecurse( $text ) {
 343                 $titles = self::newFromRedirectArray( $text );
 344                 return $titles ? array_pop( $titles ) : null;
 345         }
 346
 347         /**
 348          * Extract a redirect destination from a string and return an
 349          * array of Titles, or null if the text doesn't contain a valid redirect
 350          * The last element in the array is the final destination after all redirects
 351          * have been resolved (up to $wgMaxRedirects times)
 352          *
 353          * @param $text \type{\string} Text with possible redirect
 354          * @return \type{\array} Array of Titles, with the destination last
 355          */
 356         public static function newFromRedirectArray( $text ) {
 357                 global $wgMaxRedirects;
 358                 // are redirects disabled?
 359                 if ( $wgMaxRedirects < 1 ) {
 360                         return null;
 361                 }
 362                 $title = self::newFromRedirectInternal( $text );
 363                 if ( is_null( $title ) ) {
 364                         return null;
 365                 }
 366                 // recursive check to follow double redirects
 367                 $recurse = $wgMaxRedirects;
 368                 $titles = array( $title );
 369                 while ( --$recurse > 0 ) {
 370                         if ( $title->isRedirect() ) {
 371                                 $article = new Article( $title, 0 );
 372                                 $newtitle = $article->getRedirectTarget();
 373                         } else {
 374                                 break;
 375                         }
 376                         // Redirects to some special pages are not permitted
 377                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 378                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 379                                 $title = $newtitle;
 380                                 $titles[] = $newtitle;
 381                         } else {
 382                                 break;
 383                         }
 384                 }
 385                 return $titles;
 386         }
 387
 388         /**
 389          * Really extract the redirect destination
 390          * Do not call this function directly, use one of the newFromRedirect* functions above
 391          *
 392          * @param $text \type{\string} Text with possible redirect
 393          * @return \type{Title} The corresponding Title
 394          */
 395         protected static function newFromRedirectInternal( $text ) {
 396                 $redir = MagicWord::get( 'redirect' );
 397                 $text = trim( $text );
 398                 if ( $redir->matchStartAndRemove( $text ) ) {
 399                         // Extract the first link and see if it's usable
 400                         // Ensure that it really does come directly after #REDIRECT
 401                         // Some older redirects included a colon, so don't freak about that!
 402                         $m = array();
 403                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 404                                 // Strip preceding colon used to "escape" categories, etc.
 405                                 // and URL-decode links
 406                                 if ( strpos( $m[1], '%' ) !== false ) {
 407                                         // Match behavior of inline link parsing here;
 408                                         // don't interpret + as " " most of the time!
 409                                         // It might be safe to just use rawurldecode instead, though.
 410                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 411                                 }
 412                                 $title = Title::newFromText( $m[1] );
 413                                 // If the title is a redirect to bad special pages or is invalid, return null
 414                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 415                                         return null;
 416                                 }
 417                                 return $title;
 418                         }
 419                 }
 420                 return null;
 421         }
 422
 423 # ----------------------------------------------------------------------------
 424 #       Static functions
 425 # ----------------------------------------------------------------------------
 426
 427         /**
 428          * Get the prefixed DB key associated with an ID
 429          *
 430          * @param $id \type{\int} the page_id of the article
 431          * @return \type{Title} an object representing the article, or NULL
 432          *  if no such article was found
 433          */
 434         public static function nameOf( $id ) {
 435                 $dbr = wfGetDB( DB_SLAVE );
 436
 437                 $s = $dbr->selectRow(
 438                         'page',
 439                         array( 'page_namespace', 'page_title' ),
 440                         array( 'page_id' => $id ),
 441                         __METHOD__
 442                 );
 443                 if ( $s === false ) {
 444                         return null;
 445                 }
 446
 447                 $n = self::makeName( $s->page_namespace, $s->page_title );
 448                 return $n;
 449         }
 450
 451         /**
 452          * Get a regex character class describing the legal characters in a link
 453          *
 454          * @return \type{\string} the list of characters, not delimited
 455          */
 456         public static function legalChars() {
 457                 global $wgLegalTitleChars;
 458                 return $wgLegalTitleChars;
 459         }
 460
 461         /**
 462          * Get a string representation of a title suitable for
 463          * including in a search index
 464          *
 465          * @param $ns \type{\int} a namespace index
 466          * @param $title \type{\string} text-form main part
 467          * @return \type{\string} a stripped-down title string ready for the
 468          *  search index
 469          */
 470         public static function indexTitle( $ns, $title ) {
 471                 global $wgContLang;
 472
 473                 $lc = SearchEngine::legalSearchChars() . '&#;';
 474                 $t = $wgContLang->normalizeForSearch( $title );
 475                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 476                 $t = $wgContLang->lc( $t );
 477
 478                 # Handle 's, s'
 479                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 480                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 481
 482                 $t = preg_replace( "/\\s+/", ' ', $t );
 483
 484                 if ( $ns == NS_FILE ) {
 485                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 486                 }
 487                 return trim( $t );
 488         }
 489
 490         /**
 491          * Make a prefixed DB key from a DB key and a namespace index
 492          *
 493          * @param $ns \type{\int} numerical representation of the namespace
 494          * @param $title \type{\string} the DB key form the title
 495          * @param $fragment \type{\string} The link fragment (after the "#")
 496          * @param $interwiki \type{\string} The interwiki prefix
 497          * @return \type{\string} the prefixed form of the title
 498          */
 499         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 500                 global $wgContLang;
 501
 502                 $namespace = $wgContLang->getNsText( $ns );
 503                 $name = $namespace == '' ? $title : "$namespace:$title";
 504                 if ( strval( $interwiki ) != '' ) {
 505                         $name = "$interwiki:$name";
 506                 }
 507                 if ( strval( $fragment ) != '' ) {
 508                         $name .= '#' . $fragment;
 509                 }
 510                 return $name;
 511         }
 512
 513         /**
 514          * Determine whether the object refers to a page within
 515          * this project.
 516          *
 517          * @return \type{\bool} TRUE if this is an in-project interwiki link
 518          *      or a wikilink, FALSE otherwise
 519          */
 520         public function isLocal() {
 521                 if ( $this->mInterwiki != '' ) {
 522                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 523                 } else {
 524                         return true;
 525                 }
 526         }
 527
 528         /**
 529          * Determine whether the object refers to a page within
 530          * this project and is transcludable.
 531          *
 532          * @return \type{\bool} TRUE if this is transcludable
 533          */
 534         public function isTrans() {
 535                 if ( $this->mInterwiki == '' ) {
 536                         return false;
 537                 }
 538
 539                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 540         }
 541
 542         /**
 543          * Returns the DB name of the distant wiki
 544          * which owns the object.
 545          *
 546          * @return \type{\string} the DB name
 547          */
 548         public function getTransWikiID() {
 549                 if ( $this->mInterwiki == '' ) {
 550                         return false;
 551                 }
 552
 553                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 554         }
 555
 556         /**
 557          * Escape a text fragment, say from a link, for a URL
 558          *
 559          * @param $fragment string containing a URL or link fragment (after the "#")
 560          * @return String: escaped string
 561          */
 562         static function escapeFragmentForURL( $fragment ) {
 563                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 564                 # fragments appear not to work in IE (at least up to 7) or in at least
 565                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 566                 # to care if they aren't encoded.
 567                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 568         }
 569
 570 # ----------------------------------------------------------------------------
 571 #       Other stuff
 572 # ----------------------------------------------------------------------------
 573
 574         /** Simple accessors */
 575         /**
 576          * Get the text form (spaces not underscores) of the main part
 577          *
 578          * @return \type{\string} Main part of the title
 579          */
 580         public function getText() { return $this->mTextform; }
 581
 582         /**
 583          * Get the URL-encoded form of the main part
 584          *
 585          * @return \type{\string} Main part of the title, URL-encoded
 586          */
 587         public function getPartialURL() { return $this->mUrlform; }
 588
 589         /**
 590          * Get the main part with underscores
 591          *
 592          * @return \type{\string} Main part of the title, with underscores
 593          */
 594         public function getDBkey() { return $this->mDbkeyform; }
 595
 596         /**
 597          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 598          *
 599          * @return \type{\int} Namespace index
 600          */
 601         public function getNamespace() { return $this->mNamespace; }
 602
 603         /**
 604          * Get the namespace text
 605          *
 606          * @return \type{\string} Namespace text
 607          */
 608         public function getNsText() {
 609                 global $wgContLang;
 610
 611                 if ( $this->mInterwiki != '' ) {
 612                         // This probably shouldn't even happen. ohh man, oh yuck.
 613                         // But for interwiki transclusion it sometimes does.
 614                         // Shit. Shit shit shit.
 615                         //
 616                         // Use the canonical namespaces if possible to try to
 617                         // resolve a foreign namespace.
 618                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 619                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 620                         }
 621                 }
 622                 return $wgContLang->getNsText( $this->mNamespace );
 623         }
 624
 625         /**
 626          * Get the DB key with the initial letter case as specified by the user
 627          *
 628          * @return \type{\string} DB key
 629          */
 630         function getUserCaseDBKey() {
 631                 return $this->mUserCaseDBKey;
 632         }
 633
 634         /**
 635          * Get the namespace text of the subject (rather than talk) page
 636          *
 637          * @return \type{\string} Namespace text
 638          */
 639         public function getSubjectNsText() {
 640                 global $wgContLang;
 641                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 642         }
 643
 644         /**
 645          * Get the namespace text of the talk page
 646          *
 647          * @return \type{\string} Namespace text
 648          */
 649         public function getTalkNsText() {
 650                 global $wgContLang;
 651                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 652         }
 653
 654         /**
 655          * Could this title have a corresponding talk page?
 656          *
 657          * @return \type{\bool} TRUE or FALSE
 658          */
 659         public function canTalk() {
 660                 return( MWNamespace::canTalk( $this->mNamespace ) );
 661         }
 662
 663         /**
 664          * Get the interwiki prefix (or null string)
 665          *
 666          * @return \type{\string} Interwiki prefix
 667          */
 668         public function getInterwiki() { return $this->mInterwiki; }
 669
 670         /**
 671          * Get the Title fragment (i.e.\ the bit after the #) in text form
 672          *
 673          * @return \type{\string} Title fragment
 674          */
 675         public function getFragment() { return $this->mFragment; }
 676
 677         /**
 678          * Get the fragment in URL form, including the "#" character if there is one
 679          * @return \type{\string} Fragment in URL form
 680          */
 681         public function getFragmentForURL() {
 682                 if ( $this->mFragment == '' ) {
 683                         return '';
 684                 } else {
 685                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 686                 }
 687         }
 688
 689         /**
 690          * Get the default namespace index, for when there is no namespace
 691          *
 692          * @return \type{\int} Default namespace index
 693          */
 694         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 695
 696         /**
 697          * Get title for search index
 698          *
 699          * @return \type{\string} a stripped-down title string ready for the
 700          *  search index
 701          */
 702         public function getIndexTitle() {
 703                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 704         }
 705
 706         /**
 707          * Get the prefixed database key form
 708          *
 709          * @return \type{\string} the prefixed title, with underscores and
 710          *  any interwiki and namespace prefixes
 711          */
 712         public function getPrefixedDBkey() {
 713                 $s = $this->prefix( $this->mDbkeyform );
 714                 $s = str_replace( ' ', '_', $s );
 715                 return $s;
 716         }
 717
 718         /**
 719          * Get the prefixed title with spaces.
 720          * This is the form usually used for display
 721          *
 722          * @return \type{\string} the prefixed title, with spaces
 723          */
 724         public function getPrefixedText() {
 725                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 726                         $s = $this->prefix( $this->mTextform );
 727                         $s = str_replace( '_', ' ', $s );
 728                         $this->mPrefixedText = $s;
 729                 }
 730                 return $this->mPrefixedText;
 731         }
 732
 733         /**
 734          * Get the prefixed title with spaces, plus any fragment
 735          * (part beginning with '#')
 736          *
 737          * @return \type{\string} the prefixed title, with spaces and
 738          *  the fragment, including '#'
 739          */
 740         public function getFullText() {
 741                 $text = $this->getPrefixedText();
 742                 if ( $this->mFragment != '' ) {
 743                         $text .= '#' . $this->mFragment;
 744                 }
 745                 return $text;
 746         }
 747
 748         /**
 749          * Get the base name, i.e. the leftmost parts before the /
 750          *
 751          * @return \type{\string} Base name
 752          */
 753         public function getBaseText() {
 754                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 755                         return $this->getText();
 756                 }
 757
 758                 $parts = explode( '/', $this->getText() );
 759                 # Don't discard the real title if there's no subpage involved
 760                 if ( count( $parts ) > 1 ) {
 761                         unset( $parts[count( $parts ) - 1] );
 762                 }
 763                 return implode( '/', $parts );
 764         }
 765
 766         /**
 767          * Get the lowest-level subpage name, i.e. the rightmost part after /
 768          *
 769          * @return \type{\string} Subpage name
 770          */
 771         public function getSubpageText() {
 772                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 773                         return( $this->mTextform );
 774                 }
 775                 $parts = explode( '/', $this->mTextform );
 776                 return( $parts[count( $parts ) - 1] );
 777         }
 778
 779         /**
 780          * Get a URL-encoded form of the subpage text
 781          *
 782          * @return \type{\string} URL-encoded subpage name
 783          */
 784         public function getSubpageUrlForm() {
 785                 $text = $this->getSubpageText();
 786                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 787                 return( $text );
 788         }
 789
 790         /**
 791          * Get a URL-encoded title (not an actual URL) including interwiki
 792          *
 793          * @return \type{\string} the URL-encoded form
 794          */
 795         public function getPrefixedURL() {
 796                 $s = $this->prefix( $this->mDbkeyform );
 797                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 798                 return $s;
 799         }
 800
 801         /**
 802          * Get a real URL referring to this title, with interwiki link and
 803          * fragment
 804          *
 805          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 806          *   links. Can be specified as an associative array as well, e.g.,
 807          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 808          * @param $variant \type{\string} language variant of url (for sr, zh..)
 809          * @return \type{\string} the URL
 810          */
 811         public function getFullURL( $query = '', $variant = false ) {
 812                 global $wgServer, $wgRequest;
 813
 814                 if ( is_array( $query ) ) {
 815                         $query = wfArrayToCGI( $query );
 816                 }
 817
 818                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 819                 if ( !$interwiki ) {
 820                         $url = $this->getLocalURL( $query, $variant );
 821
 822                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 823                         // Correct fix would be to move the prepending elsewhere.
 824                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 825                                 $url = $wgServer . $url;
 826                         }
 827                 } else {
 828                         $baseUrl = $interwiki->getURL();
 829
 830                         $namespace = wfUrlencode( $this->getNsText() );
 831                         if ( $namespace != '' ) {
 832                                 # Can this actually happen? Interwikis shouldn't be parsed.
 833                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 834                                 $namespace .= ':';
 835                         }
 836                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 837                         $url = wfAppendQuery( $url, $query );
 838                 }
 839
 840                 # Finally, add the fragment.
 841                 $url .= $this->getFragmentForURL();
 842
 843                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 844                 return $url;
 845         }
 846
 847         /**
 848          * Get a URL with no fragment or server name.  If this page is generated
 849          * with action=render, $wgServer is prepended.
 850          *
 851          * @param $query Mixed: an optional query string; if not specified,
 852          *   $wgArticlePath will be used.  Can be specified as an associative array
 853          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 854          *   URL-escaped).
 855          * @param $variant \type{\string} language variant of url (for sr, zh..)
 856          * @return \type{\string} the URL
 857          */
 858         public function getLocalURL( $query = '', $variant = false ) {
 859                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 860                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 861
 862                 if ( is_array( $query ) ) {
 863                         $query = wfArrayToCGI( $query );
 864                 }
 865
 866                 // internal links should point to same variant as current page (only anonymous users)
 867                 if ( !$variant && $wgContLang->hasVariants() && !$wgUser->isLoggedIn() ) {
 868                         $pref = $wgContLang->getPreferredVariant( false );
 869                         if ( $pref != $wgContLang->getCode() ) {
 870                                 $variant = $pref;
 871                         }
 872                 }
 873
 874                 if ( $this->isExternal() ) {
 875                         $url = $this->getFullURL();
 876                         if ( $query ) {
 877                                 // This is currently only used for edit section links in the
 878                                 // context of interwiki transclusion. In theory we should
 879                                 // append the query to the end of any existing query string,
 880                                 // but interwiki transclusion is already broken in that case.
 881                                 $url .= "?$query";
 882                         }
 883                 } else {
 884                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 885                         if ( $query == '' ) {
 886                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 887                                         if ( !$wgVariantArticlePath ) {
 888                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 889                                         } else {
 890                                                 $variantArticlePath = $wgVariantArticlePath;
 891                                         }
 892                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 893                                         $url = str_replace( '$1', $dbkey, $url  );
 894                                 } else {
 895                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 896                                 }
 897                         } else {
 898                                 global $wgActionPaths;
 899                                 $url = false;
 900                                 $matches = array();
 901                                 if ( !empty( $wgActionPaths ) &&
 902                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 903                                 {
 904                                         $action = urldecode( $matches[2] );
 905                                         if ( isset( $wgActionPaths[$action] ) ) {
 906                                                 $query = $matches[1];
 907                                                 if ( isset( $matches[4] ) ) {
 908                                                         $query .= $matches[4];
 909                                                 }
 910                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 911                                                 if ( $query != '' ) {
 912                                                         $url = wfAppendQuery( $url, $query );
 913                                                 }
 914                                         }
 915                                 }
 916                                 if ( $url === false ) {
 917                                         if ( $query == '-' ) {
 918                                                 $query = '';
 919                                         }
 920                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 921                                 }
 922                         }
 923
 924                         // FIXME: this causes breakage in various places when we
 925                         // actually expected a local URL and end up with dupe prefixes.
 926                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 927                                 $url = $wgServer . $url;
 928                         }
 929                 }
 930                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 931                 return $url;
 932         }
 933
 934         /**
 935          * Get a URL that's the simplest URL that will be valid to link, locally,
 936          * to the current Title.  It includes the fragment, but does not include
 937          * the server unless action=render is used (or the link is external).  If
 938          * there's a fragment but the prefixed text is empty, we just return a link
 939          * to the fragment.
 940          *
 941          * The result obviously should not be URL-escaped, but does need to be
 942          * HTML-escaped if it's being output in HTML.
 943          *
 944          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 945          *   query string.  Keys and values will be escaped.
 946          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 947          *   for external links.  Default is "false" (same variant as current page,
 948          *   for anonymous users).
 949          * @return \type{\string} the URL
 950          */
 951         public function getLinkUrl( $query = array(), $variant = false ) {
 952                 wfProfileIn( __METHOD__ );
 953                 if ( $this->isExternal() ) {
 954                         $ret = $this->getFullURL( $query );
 955                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 956                         $ret = $this->getFragmentForURL();
 957                 } else {
 958                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 959                 }
 960                 wfProfileOut( __METHOD__ );
 961                 return $ret;
 962         }
 963
 964         /**
 965          * Get an HTML-escaped version of the URL form, suitable for
 966          * using in a link, without a server name or fragment
 967          *
 968          * @param $query \type{\string} an optional query string
 969          * @return \type{\string} the URL
 970          */
 971         public function escapeLocalURL( $query = '' ) {
 972                 return htmlspecialchars( $this->getLocalURL( $query ) );
 973         }
 974
 975         /**
 976          * Get an HTML-escaped version of the URL form, suitable for
 977          * using in a link, including the server name and fragment
 978          *
 979          * @param $query \type{\string} an optional query string
 980          * @return \type{\string} the URL
 981          */
 982         public function escapeFullURL( $query = '' ) {
 983                 return htmlspecialchars( $this->getFullURL( $query ) );
 984         }
 985
 986         /**
 987          * Get the URL form for an internal link.
 988          * - Used in various Squid-related code, in case we have a different
 989          * internal hostname for the server from the exposed one.
 990          *
 991          * @param $query \type{\string} an optional query string
 992          * @param $variant \type{\string} language variant of url (for sr, zh..)
 993          * @return \type{\string} the URL
 994          */
 995         public function getInternalURL( $query = '', $variant = false ) {
 996                 global $wgInternalServer;
 997                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 998                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 999                 return $url;
1000         }
1001
1002         /**
1003          * Get the edit URL for this Title
1004          *
1005          * @return \type{\string} the URL, or a null string if this is an
1006          *  interwiki link
1007          */
1008         public function getEditURL() {
1009                 if ( $this->mInterwiki != '' ) {
1010                         return '';
1011                 }
1012                 $s = $this->getLocalURL( 'action=edit' );
1013
1014                 return $s;
1015         }
1016
1017         /**
1018          * Get the HTML-escaped displayable text form.
1019          * Used for the title field in <a> tags.
1020          *
1021          * @return \type{\string} the text, including any prefixes
1022          */
1023         public function getEscapedText() {
1024                 return htmlspecialchars( $this->getPrefixedText() );
1025         }
1026
1027         /**
1028          * Is this Title interwiki?
1029          *
1030          * @return \type{\bool}
1031          */
1032         public function isExternal() {
1033                 return ( $this->mInterwiki != '' );
1034         }
1035
1036         /**
1037          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1038          *
1039          * @param $action \type{\string} Action to check (default: edit)
1040          * @return \type{\bool}
1041          */
1042         public function isSemiProtected( $action = 'edit' ) {
1043                 if ( $this->exists() ) {
1044                         $restrictions = $this->getRestrictions( $action );
1045                         if ( count( $restrictions ) > 0 ) {
1046                                 foreach ( $restrictions as $restriction ) {
1047                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1048                                                 return false;
1049                                         }
1050                                 }
1051                         } else {
1052                                 # Not protected
1053                                 return false;
1054                         }
1055                         return true;
1056                 } else {
1057                         # If it doesn't exist, it can't be protected
1058                         return false;
1059                 }
1060         }
1061
1062         /**
1063          * Does the title correspond to a protected article?
1064          *
1065          * @param $action \type{\string} the action the page is protected from,
1066          * by default checks all actions.
1067          * @return \type{\bool}
1068          */
1069         public function isProtected( $action = '' ) {
1070                 global $wgRestrictionLevels;
1071
1072                 $restrictionTypes = $this->getRestrictionTypes();
1073
1074                 # Special pages have inherent protection
1075                 if( $this->getNamespace() == NS_SPECIAL ) {
1076                         return true;
1077                 }
1078
1079                 # Check regular protection levels
1080                 foreach ( $restrictionTypes as $type ) {
1081                         if ( $action == $type || $action == '' ) {
1082                                 $r = $this->getRestrictions( $type );
1083                                 foreach ( $wgRestrictionLevels as $level ) {
1084                                         if ( in_array( $level, $r ) && $level != '' ) {
1085                                                 return true;
1086                                         }
1087                                 }
1088                         }
1089                 }
1090
1091                 return false;
1092         }
1093
1094         /**
1095          * Is this a conversion table for the LanguageConverter?
1096          *
1097          * @return \type{\bool}
1098          */
1099         public function isConversionTable() {
1100                 if(
1101                         $this->getNamespace() == NS_MEDIAWIKI &&
1102                         strpos( $this->getText(), 'Conversiontable' ) !== false
1103                 )
1104                 {
1105                         return true;
1106                 }
1107
1108                 return false;
1109         }
1110
1111         /**
1112          * Is $wgUser watching this page?
1113          *
1114          * @return \type{\bool}
1115          */
1116         public function userIsWatching() {
1117                 global $wgUser;
1118
1119                 if ( is_null( $this->mWatched ) ) {
1120                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1121                                 $this->mWatched = false;
1122                         } else {
1123                                 $this->mWatched = $wgUser->isWatched( $this );
1124                         }
1125                 }
1126                 return $this->mWatched;
1127         }
1128
1129         /**
1130          * Can $wgUser perform $action on this page?
1131          * This skips potentially expensive cascading permission checks
1132          * as well as avoids expensive error formatting
1133          *
1134          * Suitable for use for nonessential UI controls in common cases, but
1135          * _not_ for functional access control.
1136          *
1137          * May provide false positives, but should never provide a false negative.
1138          *
1139          * @param $action \type{\string} action that permission needs to be checked for
1140          * @return \type{\bool}
1141          */
1142         public function quickUserCan( $action ) {
1143                 return $this->userCan( $action, false );
1144         }
1145
1146         /**
1147          * Determines if $wgUser is unable to edit this page because it has been protected
1148          * by $wgNamespaceProtection.
1149          *
1150          * @return \type{\bool}
1151          */
1152         public function isNamespaceProtected() {
1153                 global $wgNamespaceProtection, $wgUser;
1154                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1155                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1156                                 if ( $right != '' && !$wgUser->isAllowed( $right ) ) {
1157                                         return true;
1158                                 }
1159                         }
1160                 }
1161                 return false;
1162         }
1163
1164         /**
1165          * Can $wgUser perform $action on this page?
1166          *
1167          * @param $action \type{\string} action that permission needs to be checked for
1168          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1169          * @return \type{\bool}
1170          */
1171         public function userCan( $action, $doExpensiveQueries = true ) {
1172                 global $wgUser;
1173                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1174         }
1175
1176         /**
1177          * Can $user perform $action on this page?
1178          *
1179          * FIXME: This *does not* check throttles (User::pingLimiter()).
1180          *
1181          * @param $action \type{\string}action that permission needs to be checked for
1182          * @param $user \type{User} user to check
1183          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1184          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1185          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1186          */
1187         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1188                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1189
1190                 // Remove the errors being ignored.
1191                 foreach ( $errors as $index => $error ) {
1192                         $error_key = is_array( $error ) ? $error[0] : $error;
1193
1194                         if ( in_array( $error_key, $ignoreErrors ) ) {
1195                                 unset( $errors[$index] );
1196                         }
1197                 }
1198
1199                 return $errors;
1200         }
1201
1202         /**
1203          * Permissions checks that fail most often, and which are easiest to test.
1204          *
1205          * @param $action String the action to check
1206          * @param $user User user to check
1207          * @param $errors Array list of current errors
1208          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1209          * @param $short Boolean short circuit on first error
1210          *
1211          * @return Array list of errors
1212          */
1213         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1214                 if ( $action == 'create' ) {
1215                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1216                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1217                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1218                         }
1219                 } elseif ( $action == 'move' ) {
1220                         if ( !$user->isAllowed( 'move-rootuserpages' )
1221                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1222                                 // Show user page-specific message only if the user can move other pages
1223                                 $errors[] = array( 'cant-move-user-page' );
1224                         }
1225
1226                         // Check if user is allowed to move files if it's a file
1227                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1228                                 $errors[] = array( 'movenotallowedfile' );
1229                         }
1230
1231                         if ( !$user->isAllowed( 'move' ) ) {
1232                                 // User can't move anything
1233                                 global $wgGroupPermissions;
1234                                 $userCanMove = false;
1235                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1236                                         $userCanMove = $wgGroupPermissions['user']['move'];
1237                                 }
1238                                 $autoconfirmedCanMove = false;
1239                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1240                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1241                                 }
1242                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1243                                         // custom message if logged-in users without any special rights can move
1244                                         $errors[] = array( 'movenologintext' );
1245                                 } else {
1246                                         $errors[] = array( 'movenotallowed' );
1247                                 }
1248                         }
1249                 } elseif ( $action == 'move-target' ) {
1250                         if ( !$user->isAllowed( 'move' ) ) {
1251                                 // User can't move anything
1252                                 $errors[] = array( 'movenotallowed' );
1253                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1254                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1255                                 // Show user page-specific message only if the user can move other pages
1256                                 $errors[] = array( 'cant-move-to-user-page' );
1257                         }
1258                 } elseif ( !$user->isAllowed( $action ) ) {
1259                         // We avoid expensive display logic for quickUserCan's and such
1260                         $groups = false;
1261                         if ( !$short ) {
1262                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1263                                         User::getGroupsWithPermission( $action ) );
1264                         }
1265
1266                         if ( $groups ) {
1267                                 global $wgLang;
1268                                 $return = array(
1269                                         'badaccess-groups',
1270                                         $wgLang->commaList( $groups ),
1271                                         count( $groups )
1272                                 );
1273                         } else {
1274                                 $return = array( 'badaccess-group0' );
1275                         }
1276                         $errors[] = $return;
1277                 }
1278
1279                 return $errors;
1280         }
1281
1282         /**
1283          * Add the resulting error code to the errors array
1284          *
1285          * @param $errors Array list of current errors
1286          * @param $result Mixed result of errors
1287          *
1288          * @return Array list of errors
1289          */
1290         private function resultToError( $errors, $result ) {
1291                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1292                         // A single array representing an error
1293                         $errors[] = $result;
1294                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1295                         // A nested array representing multiple errors
1296                         $errors = array_merge( $errors, $result );
1297                 } else if ( $result !== '' && is_string( $result ) ) {
1298                         // A string representing a message-id
1299                         $errors[] = array( $result );
1300                 } else if ( $result === false ) {
1301                         // a generic "We don't want them to do that"
1302                         $errors[] = array( 'badaccess-group0' );
1303                 }
1304                 return $errors;
1305         }
1306
1307         /**
1308          * Check various permission hooks
1309          * @see checkQuickPermissions for parameter information
1310          */
1311         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1312                 // Use getUserPermissionsErrors instead
1313                 $result = '';
1314                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1315                         return $result ? array() : array( array( 'badaccess-group0' ) );
1316                 }
1317                 // Check getUserPermissionsErrors hook
1318                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1319                         $errors = $this->resultToError( $errors, $result );
1320                 }
1321                 // Check getUserPermissionsErrorsExpensive hook
1322                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1323                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1324                         $errors = $this->resultToError( $errors, $result );
1325                 }
1326
1327                 return $errors;
1328         }
1329
1330         /**
1331          * Check permissions on special pages & namespaces
1332          * @see checkQuickPermissions for parameter information
1333          */
1334         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1335                 # Only 'createaccount' and 'execute' can be performed on
1336                 # special pages, which don't actually exist in the DB.
1337                 $specialOKActions = array( 'createaccount', 'execute' );
1338                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1339                         $errors[] = array( 'ns-specialprotected' );
1340                 }
1341
1342                 # Check $wgNamespaceProtection for restricted namespaces
1343                 if ( $this->isNamespaceProtected() ) {
1344                         $ns = $this->mNamespace == NS_MAIN ?
1345                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1346                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1347                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1348                 }
1349
1350                 return $errors;
1351         }
1352
1353         /**
1354          * Check CSS/JS sub-page permissions
1355          * @see checkQuickPermissions for parameter information
1356          */
1357         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1358                 # Protect css/js subpages of user pages
1359                 # XXX: this might be better using restrictions
1360                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1361                 #      and $this->userCanEditJsSubpage() from working
1362                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1363                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1364                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1365                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1366                                 $errors[] = array( 'customcssjsprotected' );
1367                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1368                                 $errors[] = array( 'customcssjsprotected' );
1369                         }
1370                 }
1371
1372                 return $errors;
1373         }
1374
1375         /**
1376          * Check against page_restrictions table requirements on this
1377          * page. The user must possess all required rights for this
1378          * action.
1379          * @see checkQuickPermissions for parameter information
1380          */
1381         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1382                 foreach ( $this->getRestrictions( $action ) as $right ) {
1383                         // Backwards compatibility, rewrite sysop -> protect
1384                         if ( $right == 'sysop' ) {
1385                                 $right = 'protect';
1386                         }
1387                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1388                                 // Users with 'editprotected' permission can edit protected pages
1389                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1390                                         // Users with 'editprotected' permission cannot edit protected pages
1391                                         // with cascading option turned on.
1392                                         if ( $this->mCascadeRestriction ) {
1393                                                 $errors[] = array( 'protectedpagetext', $right );
1394                                         }
1395                                 } else {
1396                                         $errors[] = array( 'protectedpagetext', $right );
1397                                 }
1398                         }
1399                 }
1400
1401                 return $errors;
1402         }
1403
1404         /**
1405          * Check restrictions on cascading pages.
1406          * @see checkQuickPermissions for parameter information
1407          */
1408         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1409                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1410                         # We /could/ use the protection level on the source page, but it's
1411                         # fairly ugly as we have to establish a precedence hierarchy for pages
1412                         # included by multiple cascade-protected pages. So just restrict
1413                         # it to people with 'protect' permission, as they could remove the
1414                         # protection anyway.
1415                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1416                         # Cascading protection depends on more than this page...
1417                         # Several cascading protected pages may include this page...
1418                         # Check each cascading level
1419                         # This is only for protection restrictions, not for all actions
1420                         if ( isset( $restrictions[$action] ) ) {
1421                                 foreach ( $restrictions[$action] as $right ) {
1422                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1423                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1424                                                 $pages = '';
1425                                                 foreach ( $cascadingSources as $page )
1426                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1427                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1428                                         }
1429                                 }
1430                         }
1431                 }
1432
1433                 return $errors;
1434         }
1435
1436         /**
1437          * Check action permissions not already checked in checkQuickPermissions
1438          * @see checkQuickPermissions for parameter information
1439          */
1440         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1441                 if ( $action == 'protect' ) {
1442                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1443                                 // If they can't edit, they shouldn't protect.
1444                                 $errors[] = array( 'protect-cantedit' );
1445                         }
1446                 } elseif ( $action == 'create' ) {
1447                         $title_protection = $this->getTitleProtection();
1448                         if( $title_protection ) {
1449                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1450                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1451                                 }
1452                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1453                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1454                                 }
1455                         }
1456                 } elseif ( $action == 'move' ) {
1457                         // Check for immobile pages
1458                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1459                                 // Specific message for this case
1460                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1461                         } elseif ( !$this->isMovable() ) {
1462                                 // Less specific message for rarer cases
1463                                 $errors[] = array( 'immobile-page' );
1464                         }
1465                 } elseif ( $action == 'move-target' ) {
1466                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1467                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1468                         } elseif ( !$this->isMovable() ) {
1469                                 $errors[] = array( 'immobile-target-page' );
1470                         }
1471                 }
1472                 return $errors;
1473         }
1474
1475         /**
1476          * Check that the user isn't blocked from editting.
1477          * @see checkQuickPermissions for parameter information
1478          */
1479         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1480                 if( $short ) {
1481                         return $errors;
1482                 }
1483
1484                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1485
1486                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1487                         $errors[] = array( 'confirmedittext' );
1488                 }
1489
1490                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1491                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1492                         $block = $user->mBlock;
1493
1494                         // This is from OutputPage::blockedPage
1495                         // Copied at r23888 by werdna
1496
1497                         $id = $user->blockedBy();
1498                         $reason = $user->blockedFor();
1499                         if ( $reason == '' ) {
1500                                 $reason = wfMsg( 'blockednoreason' );
1501                         }
1502                         $ip = wfGetIP();
1503
1504                         if ( is_numeric( $id ) ) {
1505                                 $name = User::whoIs( $id );
1506                         } else {
1507                                 $name = $id;
1508                         }
1509
1510                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1511                         $blockid = $block->mId;
1512                         $blockExpiry = $user->mBlock->mExpiry;
1513                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1514                         if ( $blockExpiry == 'infinity' ) {
1515                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1516                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1517
1518                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1519                                         if ( !strpos( $option, ':' ) )
1520                                                 continue;
1521
1522                                         list( $show, $value ) = explode( ':', $option );
1523
1524                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1525                                                 $blockExpiry = $show;
1526                                                 break;
1527                                         }
1528                                 }
1529                         } else {
1530                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1531                         }
1532
1533                         $intended = $user->mBlock->mAddress;
1534
1535                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1536                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1537                 }
1538
1539                 return $errors;
1540         }
1541
1542         /**
1543          * Can $user perform $action on this page? This is an internal function,
1544          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1545          * checks on wfReadOnly() and blocks)
1546          *
1547          * @param $action \type{\string} action that permission needs to be checked for
1548          * @param $user \type{User} user to check
1549          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1550          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1551          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1552          */
1553         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1554                 wfProfileIn( __METHOD__ );
1555
1556                 $errors = array();
1557                 $checks = array(
1558                         'checkQuickPermissions',
1559                         'checkPermissionHooks',
1560                         'checkSpecialsAndNSPermissions',
1561                         'checkCSSandJSPermissions',
1562                         'checkPageRestrictions',
1563                         'checkCascadingSourcesRestrictions',
1564                         'checkActionPermissions',
1565                         'checkUserBlock'
1566                 );
1567
1568                 while( count( $checks ) > 0 &&
1569                            !( $short && count( $errors ) > 0 ) ) {
1570                         $method = array_shift( $checks );
1571                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1572                 }
1573
1574                 wfProfileOut( __METHOD__ );
1575                 return $errors;
1576         }
1577
1578         /**
1579          * Is this title subject to title protection?
1580          *
1581          * @return \type{\mixed} An associative array representing any existent title
1582          *   protection, or false if there's none.
1583          */
1584         private function getTitleProtection() {
1585                 // Can't protect pages in special namespaces
1586                 if ( $this->getNamespace() < 0 ) {
1587                         return false;
1588                 }
1589
1590                 // Can't protect pages that exist.
1591                 if ( $this->exists() ) {
1592                         return false;
1593                 }
1594
1595                 if ( !isset( $this->mTitleProtection ) ) {
1596                         $dbr = wfGetDB( DB_SLAVE );
1597                         $res = $dbr->select( 'protected_titles', '*',
1598                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1599                                 __METHOD__ );
1600
1601                         // fetchRow returns false if there are no rows.
1602                         $this->mTitleProtection = $dbr->fetchRow( $res );
1603                 }
1604                 return $this->mTitleProtection;
1605         }
1606
1607         /**
1608          * Update the title protection status
1609          *
1610          * @param $create_perm \type{\string} Permission required for creation
1611          * @param $reason \type{\string} Reason for protection
1612          * @param $expiry \type{\string} Expiry timestamp
1613          * @return boolean true
1614          */
1615         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1616                 global $wgUser, $wgContLang;
1617
1618                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1619                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1620                         // No change
1621                         return true;
1622                 }
1623
1624                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1625
1626                 $dbw = wfGetDB( DB_MASTER );
1627
1628                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1629
1630                 $expiry_description = '';
1631                 if ( $encodedExpiry != 'infinity' ) {
1632                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1633                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1634                 } else {
1635                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1636                 }
1637
1638                 # Update protection table
1639                 if ( $create_perm != '' ) {
1640                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1641                                 array(
1642                                         'pt_namespace' => $namespace,
1643                                         'pt_title' => $title,
1644                                         'pt_create_perm' => $create_perm,
1645                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1646                                         'pt_expiry' => $encodedExpiry,
1647                                         'pt_user' => $wgUser->getId(),
1648                                         'pt_reason' => $reason,
1649                                 ), __METHOD__
1650                         );
1651                 } else {
1652                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1653                                 'pt_title' => $title ), __METHOD__ );
1654                 }
1655                 # Update the protection log
1656                 if ( $dbw->affectedRows() ) {
1657                         $log = new LogPage( 'protect' );
1658
1659                         if ( $create_perm ) {
1660                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1661                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1662                         } else {
1663                                 $log->addEntry( 'unprotect', $this, $reason );
1664                         }
1665                 }
1666
1667                 return true;
1668         }
1669
1670         /**
1671          * Remove any title protection due to page existing
1672          */
1673         public function deleteTitleProtection() {
1674                 $dbw = wfGetDB( DB_MASTER );
1675
1676                 $dbw->delete(
1677                         'protected_titles',
1678                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1679                         __METHOD__
1680                 );
1681         }
1682
1683         /**
1684          * Would anybody with sufficient privileges be able to move this page?
1685          * Some pages just aren't movable.
1686          *
1687          * @return \type{\bool} TRUE or FALSE
1688          */
1689         public function isMovable() {
1690                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1691         }
1692
1693         /**
1694          * Can $wgUser read this page?
1695          *
1696          * @return \type{\bool}
1697          * @todo fold these checks into userCan()
1698          */
1699         public function userCanRead() {
1700                 global $wgUser, $wgGroupPermissions;
1701
1702                 static $useShortcut = null;
1703
1704                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1705                 if ( is_null( $useShortcut ) ) {
1706                         global $wgRevokePermissions;
1707                         $useShortcut = true;
1708                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1709                                 # Not a public wiki, so no shortcut
1710                                 $useShortcut = false;
1711                         } elseif ( !empty( $wgRevokePermissions ) ) {
1712                                 /*
1713                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1714                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1715                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1716                                  * reading is allowed.
1717                                  */
1718                                 foreach ( $wgRevokePermissions as $perms ) {
1719                                         if ( !empty( $perms['read'] ) ) {
1720                                                 # We might be removing the read right from the user, so no shortcut
1721                                                 $useShortcut = false;
1722                                                 break;
1723                                         }
1724                                 }
1725                         }
1726                 }
1727
1728                 $result = null;
1729                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1730                 if ( $result !== null ) {
1731                         return $result;
1732                 }
1733
1734                 # Shortcut for public wikis, allows skipping quite a bit of code
1735                 if ( $useShortcut ) {
1736                         return true;
1737                 }
1738
1739                 if ( $wgUser->isAllowed( 'read' ) ) {
1740                         return true;
1741                 } else {
1742                         global $wgWhitelistRead;
1743
1744                         /**
1745                          * Always grant access to the login page.
1746                          * Even anons need to be able to log in.
1747                         */
1748                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1749                                 return true;
1750                         }
1751
1752                         /**
1753                          * Bail out if there isn't whitelist
1754                          */
1755                         if ( !is_array( $wgWhitelistRead ) ) {
1756                                 return false;
1757                         }
1758
1759                         /**
1760                          * Check for explicit whitelisting
1761                          */
1762                         $name = $this->getPrefixedText();
1763                         $dbName = $this->getPrefixedDBKey();
1764                         // Check with and without underscores
1765                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1766                                 return true;
1767
1768                         /**
1769                          * Old settings might have the title prefixed with
1770                          * a colon for main-namespace pages
1771                          */
1772                         if ( $this->getNamespace() == NS_MAIN ) {
1773                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1774                                         return true;
1775                                 }
1776                         }
1777
1778                         /**
1779                          * If it's a special page, ditch the subpage bit
1780                          * and check again
1781                          */
1782                         if ( $this->getNamespace() == NS_SPECIAL ) {
1783                                 $name = $this->getDBkey();
1784                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1785                                 if ( $name === false ) {
1786                                         # Invalid special page, but we show standard login required message
1787                                         return false;
1788                                 }
1789
1790                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1791                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1792                                         return true;
1793                                 }
1794                         }
1795
1796                 }
1797                 return false;
1798         }
1799
1800         /**
1801          * Is this a talk page of some sort?
1802          *
1803          * @return \type{\bool}
1804          */
1805         public function isTalkPage() {
1806                 return MWNamespace::isTalk( $this->getNamespace() );
1807         }
1808
1809         /**
1810          * Is this a subpage?
1811          *
1812          * @return \type{\bool}
1813          */
1814         public function isSubpage() {
1815                 return MWNamespace::hasSubpages( $this->mNamespace )
1816                         ? strpos( $this->getText(), '/' ) !== false
1817                         : false;
1818         }
1819
1820         /**
1821          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1822          *
1823          * @return \type{\bool}
1824          */
1825         public function hasSubpages() {
1826                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1827                         # Duh
1828                         return false;
1829                 }
1830
1831                 # We dynamically add a member variable for the purpose of this method
1832                 # alone to cache the result.  There's no point in having it hanging
1833                 # around uninitialized in every Title object; therefore we only add it
1834                 # if needed and don't declare it statically.
1835                 if ( isset( $this->mHasSubpages ) ) {
1836                         return $this->mHasSubpages;
1837                 }
1838
1839                 $subpages = $this->getSubpages( 1 );
1840                 if ( $subpages instanceof TitleArray ) {
1841                         return $this->mHasSubpages = (bool)$subpages->count();
1842                 }
1843                 return $this->mHasSubpages = false;
1844         }
1845
1846         /**
1847          * Get all subpages of this page.
1848          *
1849          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1850          * @return mixed TitleArray, or empty array if this page's namespace
1851          *  doesn't allow subpages
1852          */
1853         public function getSubpages( $limit = -1 ) {
1854                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1855                         return array();
1856                 }
1857
1858                 $dbr = wfGetDB( DB_SLAVE );
1859                 $conds['page_namespace'] = $this->getNamespace();
1860                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1861                 $options = array();
1862                 if ( $limit > -1 ) {
1863                         $options['LIMIT'] = $limit;
1864                 }
1865                 return $this->mSubpages = TitleArray::newFromResult(
1866                         $dbr->select( 'page',
1867                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1868                                 $conds,
1869                                 __METHOD__,
1870                                 $options
1871                         )
1872                 );
1873         }
1874
1875         /**
1876          * Could this page contain custom CSS or JavaScript, based
1877          * on the title?
1878          *
1879          * @return \type{\bool}
1880          */
1881         public function isCssOrJsPage() {
1882                 return $this->mNamespace == NS_MEDIAWIKI
1883                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1884         }
1885
1886         /**
1887          * Is this a .css or .js subpage of a user page?
1888          * @return \type{\bool}
1889          */
1890         public function isCssJsSubpage() {
1891                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1892         }
1893
1894         /**
1895          * Is this a *valid* .css or .js subpage of a user page?
1896          * Check that the corresponding skin exists
1897          *
1898          * @return \type{\bool}
1899          */
1900         public function isValidCssJsSubpage() {
1901                 if ( $this->isCssJsSubpage() ) {
1902                         $name = $this->getSkinFromCssJsSubpage();
1903                         if ( $name == 'common' ) {
1904                                 return true;
1905                         }
1906                         $skinNames = Skin::getSkinNames();
1907                         return array_key_exists( $name, $skinNames );
1908                 } else {
1909                         return false;
1910                 }
1911         }
1912
1913         /**
1914          * Trim down a .css or .js subpage title to get the corresponding skin name
1915          *
1916          * @return string containing skin name from .css or .js subpage title
1917          */
1918         public function getSkinFromCssJsSubpage() {
1919                 $subpage = explode( '/', $this->mTextform );
1920                 $subpage = $subpage[ count( $subpage ) - 1 ];
1921                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1922         }
1923
1924         /**
1925          * Is this a .css subpage of a user page?
1926          *
1927          * @return \type{\bool}
1928          */
1929         public function isCssSubpage() {
1930                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1931         }
1932
1933         /**
1934          * Is this a .js subpage of a user page?
1935          *
1936          * @return \type{\bool}
1937          */
1938         public function isJsSubpage() {
1939                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1940         }
1941
1942         /**
1943          * Protect css subpages of user pages: can $wgUser edit
1944          * this page?
1945          *
1946          * @return \type{\bool}
1947          * @todo XXX: this might be better using restrictions
1948          */
1949         public function userCanEditCssSubpage() {
1950                 global $wgUser;
1951                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1952                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1953         }
1954
1955         /**
1956          * Protect js subpages of user pages: can $wgUser edit
1957          * this page?
1958          *
1959          * @return \type{\bool}
1960          * @todo XXX: this might be better using restrictions
1961          */
1962         public function userCanEditJsSubpage() {
1963                 global $wgUser;
1964                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1965                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1966         }
1967
1968         /**
1969          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1970          *
1971          * @return \type{\bool} If the page is subject to cascading restrictions.
1972          */
1973         public function isCascadeProtected() {
1974                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1975                 return ( $sources > 0 );
1976         }
1977
1978         /**
1979          * Cascading protection: Get the source of any cascading restrictions on this page.
1980          *
1981          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1982          *        that the restrictions have come from.
1983          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1984          *         objects of the pages from which cascading restrictions have come,
1985          *         false for none, or true if such restrictions exist, but $getPages was not set.
1986          *         The restriction array is an array of each type, each of which contains a
1987          *         array of unique groups.
1988          */
1989         public function getCascadeProtectionSources( $getPages = true ) {
1990                 $pagerestrictions = array();
1991
1992                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1993                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1994                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
1995                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1996                 }
1997
1998                 wfProfileIn( __METHOD__ );
1999
2000                 $dbr = wfGetDB( DB_SLAVE );
2001
2002                 if ( $this->getNamespace() == NS_FILE ) {
2003                         $tables = array( 'imagelinks', 'page_restrictions' );
2004                         $where_clauses = array(
2005                                 'il_to' => $this->getDBkey(),
2006                                 'il_from=pr_page',
2007                                 'pr_cascade' => 1
2008                         );
2009                 } else {
2010                         $tables = array( 'templatelinks', 'page_restrictions' );
2011                         $where_clauses = array(
2012                                 'tl_namespace' => $this->getNamespace(),
2013                                 'tl_title' => $this->getDBkey(),
2014                                 'tl_from=pr_page',
2015                                 'pr_cascade' => 1
2016                         );
2017                 }
2018
2019                 if ( $getPages ) {
2020                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2021                                                    'pr_expiry', 'pr_type', 'pr_level' );
2022                         $where_clauses[] = 'page_id=pr_page';
2023                         $tables[] = 'page';
2024                 } else {
2025                         $cols = array( 'pr_expiry' );
2026                 }
2027
2028                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2029
2030                 $sources = $getPages ? array() : false;
2031                 $now = wfTimestampNow();
2032                 $purgeExpired = false;
2033
2034                 foreach ( $res as $row ) {
2035                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2036                         if ( $expiry > $now ) {
2037                                 if ( $getPages ) {
2038                                         $page_id = $row->pr_page;
2039                                         $page_ns = $row->page_namespace;
2040                                         $page_title = $row->page_title;
2041                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2042                                         # Add groups needed for each restriction type if its not already there
2043                                         # Make sure this restriction type still exists
2044
2045                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2046                                                 $pagerestrictions[$row->pr_type] = array();
2047                                         }
2048
2049                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2050                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2051                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2052                                         }
2053                                 } else {
2054                                         $sources = true;
2055                                 }
2056                         } else {
2057                                 // Trigger lazy purge of expired restrictions from the db
2058                                 $purgeExpired = true;
2059                         }
2060                 }
2061                 if ( $purgeExpired ) {
2062                         Title::purgeExpiredRestrictions();
2063                 }
2064
2065                 wfProfileOut( __METHOD__ );
2066
2067                 if ( $getPages ) {
2068                         $this->mCascadeSources = $sources;
2069                         $this->mCascadingRestrictions = $pagerestrictions;
2070                 } else {
2071                         $this->mHasCascadingRestrictions = $sources;
2072                 }
2073
2074                 return array( $sources, $pagerestrictions );
2075         }
2076
2077         /**
2078          * Returns cascading restrictions for the current article
2079          *
2080          * @return Boolean
2081          */
2082         function areRestrictionsCascading() {
2083                 if ( !$this->mRestrictionsLoaded ) {
2084                         $this->loadRestrictions();
2085                 }
2086
2087                 return $this->mCascadeRestriction;
2088         }
2089
2090         /**
2091          * Loads a string into mRestrictions array
2092          *
2093          * @param $res \type{Resource} restrictions as an SQL result.
2094          * @param $oldFashionedRestrictions string comma-separated list of page
2095          *        restrictions from page table (pre 1.10)
2096          */
2097         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2098                 $rows = array();
2099
2100                 foreach ( $res as $row ) {
2101                         $rows[] = $row;
2102                 }
2103
2104                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2105         }
2106
2107         /**
2108          * Compiles list of active page restrictions from both page table (pre 1.10)
2109          * and page_restrictions table
2110          *
2111          * @param $rows array of db result objects
2112          * @param $oldFashionedRestrictions string comma-separated list of page
2113          *        restrictions from page table (pre 1.10)
2114          */
2115         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2116                 $dbr = wfGetDB( DB_SLAVE );
2117
2118                 $restrictionTypes = $this->getRestrictionTypes();
2119
2120                 foreach ( $restrictionTypes as $type ) {
2121                         $this->mRestrictions[$type] = array();
2122                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2123                 }
2124
2125                 $this->mCascadeRestriction = false;
2126
2127                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2128
2129                 if ( $oldFashionedRestrictions === null ) {
2130                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2131                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2132                 }
2133
2134                 if ( $oldFashionedRestrictions != '' ) {
2135
2136                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2137                                 $temp = explode( '=', trim( $restrict ) );
2138                                 if ( count( $temp ) == 1 ) {
2139                                         // old old format should be treated as edit/move restriction
2140                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2141                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2142                                 } else {
2143                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2144                                 }
2145                         }
2146
2147                         $this->mOldRestrictions = true;
2148
2149                 }
2150
2151                 if ( count( $rows ) ) {
2152                         # Current system - load second to make them override.
2153                         $now = wfTimestampNow();
2154                         $purgeExpired = false;
2155
2156                         foreach ( $rows as $row ) {
2157                                 # Cycle through all the restrictions.
2158
2159                                 // Don't take care of restrictions types that aren't allowed
2160
2161                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2162                                         continue;
2163
2164                                 // This code should be refactored, now that it's being used more generally,
2165                                 // But I don't really see any harm in leaving it in Block for now -werdna
2166                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2167
2168                                 // Only apply the restrictions if they haven't expired!
2169                                 if ( !$expiry || $expiry > $now ) {
2170                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2171                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2172
2173                                         $this->mCascadeRestriction |= $row->pr_cascade;
2174                                 } else {
2175                                         // Trigger a lazy purge of expired restrictions
2176                                         $purgeExpired = true;
2177                                 }
2178                         }
2179
2180                         if ( $purgeExpired ) {
2181                                 Title::purgeExpiredRestrictions();
2182                         }
2183                 }
2184
2185                 $this->mRestrictionsLoaded = true;
2186         }
2187
2188         /**
2189          * Load restrictions from the page_restrictions table
2190          *
2191          * @param $oldFashionedRestrictions string comma-separated list of page
2192          *        restrictions from page table (pre 1.10)
2193          */
2194         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2195                 if ( !$this->mRestrictionsLoaded ) {
2196                         if ( $this->exists() ) {
2197                                 $dbr = wfGetDB( DB_SLAVE );
2198
2199                                 $res = $dbr->select( 'page_restrictions', '*',
2200                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2201
2202                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2203                         } else {
2204                                 $title_protection = $this->getTitleProtection();
2205
2206                                 if ( $title_protection ) {
2207                                         $now = wfTimestampNow();
2208                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2209
2210                                         if ( !$expiry || $expiry > $now ) {
2211                                                 // Apply the restrictions
2212                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2213                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2214                                         } else { // Get rid of the old restrictions
2215                                                 Title::purgeExpiredRestrictions();
2216                                         }
2217                                 } else {
2218                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2219                                 }
2220                                 $this->mRestrictionsLoaded = true;
2221                         }
2222                 }
2223         }
2224
2225         /**
2226          * Purge expired restrictions from the page_restrictions table
2227          */
2228         static function purgeExpiredRestrictions() {
2229                 $dbw = wfGetDB( DB_MASTER );
2230                 $dbw->delete(
2231                         'page_restrictions',
2232                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2233                         __METHOD__
2234                 );
2235
2236                 $dbw->delete(
2237                         'protected_titles',
2238                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2239                         __METHOD__
2240                 );
2241         }
2242
2243         /**
2244          * Accessor/initialisation for mRestrictions
2245          *
2246          * @param $action \type{\string} action that permission needs to be checked for
2247          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2248          */
2249         public function getRestrictions( $action ) {
2250                 if ( !$this->mRestrictionsLoaded ) {
2251                         $this->loadRestrictions();
2252                 }
2253                 return isset( $this->mRestrictions[$action] )
2254                                 ? $this->mRestrictions[$action]
2255                                 : array();
2256         }
2257
2258         /**
2259          * Get the expiry time for the restriction against a given action
2260          *
2261          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2262          *      or not protected at all, or false if the action is not recognised.
2263          */
2264         public function getRestrictionExpiry( $action ) {
2265                 if ( !$this->mRestrictionsLoaded ) {
2266                         $this->loadRestrictions();
2267                 }
2268                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2269         }
2270
2271         /**
2272          * Is there a version of this page in the deletion archive?
2273          *
2274          * @return \type{\int} the number of archived revisions
2275          */
2276         public function isDeleted() {
2277                 if ( $this->getNamespace() < 0 ) {
2278                         $n = 0;
2279                 } else {
2280                         $dbr = wfGetDB( DB_SLAVE );
2281                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2282                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2283                                 __METHOD__
2284                         );
2285                         if ( $this->getNamespace() == NS_FILE ) {
2286                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2287                                         array( 'fa_name' => $this->getDBkey() ),
2288                                         __METHOD__
2289                                 );
2290                         }
2291                 }
2292                 return (int)$n;
2293         }
2294
2295         /**
2296          * Is there a version of this page in the deletion archive?
2297          *
2298          * @return Boolean
2299          */
2300         public function isDeletedQuick() {
2301                 if ( $this->getNamespace() < 0 ) {
2302                         return false;
2303                 }
2304                 $dbr = wfGetDB( DB_SLAVE );
2305                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2306                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2307                         __METHOD__
2308                 );
2309                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2310                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2311                                 array( 'fa_name' => $this->getDBkey() ),
2312                                 __METHOD__
2313                         );
2314                 }
2315                 return $deleted;
2316         }
2317
2318         /**
2319          * Get the article ID for this Title from the link cache,
2320          * adding it if necessary
2321          *
2322          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2323          *  for update
2324          * @return \type{\int} the ID
2325          */
2326         public function getArticleID( $flags = 0 ) {
2327                 if ( $this->getNamespace() < 0 ) {
2328                         return $this->mArticleID = 0;
2329                 }
2330                 $linkCache = LinkCache::singleton();
2331                 if ( $flags & self::GAID_FOR_UPDATE ) {
2332                         $oldUpdate = $linkCache->forUpdate( true );
2333                         $linkCache->clearLink( $this );
2334                         $this->mArticleID = $linkCache->addLinkObj( $this );
2335                         $linkCache->forUpdate( $oldUpdate );
2336                 } else {
2337                         if ( -1 == $this->mArticleID ) {
2338                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2339                         }
2340                 }
2341                 return $this->mArticleID;
2342         }
2343
2344         /**
2345          * Is this an article that is a redirect page?
2346          * Uses link cache, adding it if necessary
2347          *
2348          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2349          * @return \type{\bool}
2350          */
2351         public function isRedirect( $flags = 0 ) {
2352                 if ( !is_null( $this->mRedirect ) ) {
2353                         return $this->mRedirect;
2354                 }
2355                 # Calling getArticleID() loads the field from cache as needed
2356                 if ( !$this->getArticleID( $flags ) ) {
2357                         return $this->mRedirect = false;
2358                 }
2359                 $linkCache = LinkCache::singleton();
2360                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2361
2362                 return $this->mRedirect;
2363         }
2364
2365         /**
2366          * What is the length of this page?
2367          * Uses link cache, adding it if necessary
2368          *
2369          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2370          * @return \type{\bool}
2371          */
2372         public function getLength( $flags = 0 ) {
2373                 if ( $this->mLength != -1 ) {
2374                         return $this->mLength;
2375                 }
2376                 # Calling getArticleID() loads the field from cache as needed
2377                 if ( !$this->getArticleID( $flags ) ) {
2378                         return $this->mLength = 0;
2379                 }
2380                 $linkCache = LinkCache::singleton();
2381                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2382
2383                 return $this->mLength;
2384         }
2385
2386         /**
2387          * What is the page_latest field for this page?
2388          *
2389          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2390          * @return \type{\int} or 0 if the page doesn't exist
2391          */
2392         public function getLatestRevID( $flags = 0 ) {
2393                 if ( $this->mLatestID !== false ) {
2394                         return intval( $this->mLatestID );
2395                 }
2396                 # Calling getArticleID() loads the field from cache as needed
2397                 if ( !$this->getArticleID( $flags ) ) {
2398                         return $this->mLatestID = 0;
2399                 }
2400                 $linkCache = LinkCache::singleton();
2401                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2402
2403                 return $this->mLatestID;
2404         }
2405
2406         /**
2407          * This clears some fields in this object, and clears any associated
2408          * keys in the "bad links" section of the link cache.
2409          *
2410          * - This is called from Article::insertNewArticle() to allow
2411          * loading of the new page_id. It's also called from
2412          * Article::doDeleteArticle()
2413          *
2414          * @param $newid \type{\int} the new Article ID
2415          */
2416         public function resetArticleID( $newid ) {
2417                 $linkCache = LinkCache::singleton();
2418                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2419
2420                 if ( $newid === false ) {
2421                         $this->mArticleID = -1;
2422                 } else {
2423                         $this->mArticleID = intval( $newid );
2424                 }
2425                 $this->mRestrictionsLoaded = false;
2426                 $this->mRestrictions = array();
2427                 $this->mRedirect = null;
2428                 $this->mLength = -1;
2429                 $this->mLatestID = false;
2430         }
2431
2432         /**
2433          * Updates page_touched for this page; called from LinksUpdate.php
2434          *
2435          * @return \type{\bool} true if the update succeded
2436          */
2437         public function invalidateCache() {
2438                 if ( wfReadOnly() ) {
2439                         return;
2440                 }
2441                 $dbw = wfGetDB( DB_MASTER );
2442                 $success = $dbw->update(
2443                         'page',
2444                         array( 'page_touched' => $dbw->timestamp() ),
2445                         $this->pageCond(),
2446                         __METHOD__
2447                 );
2448                 HTMLFileCache::clearFileCache( $this );
2449                 return $success;
2450         }
2451
2452         /**
2453          * Prefix some arbitrary text with the namespace or interwiki prefix
2454          * of this object
2455          *
2456          * @param $name \type{\string} the text
2457          * @return \type{\string} the prefixed text
2458          * @private
2459          */
2460         /* private */ function prefix( $name ) {
2461                 $p = '';
2462                 if ( $this->mInterwiki != '' ) {
2463                         $p = $this->mInterwiki . ':';
2464                 }
2465                 if ( 0 != $this->mNamespace ) {
2466                         $p .= $this->getNsText() . ':';
2467                 }
2468                 return $p . $name;
2469         }
2470
2471         /**
2472          * Returns a simple regex that will match on characters and sequences invalid in titles.
2473          * Note that this doesn't pick up many things that could be wrong with titles, but that
2474          * replacing this regex with something valid will make many titles valid.
2475          *
2476          * @return string regex string
2477          */
2478         static function getTitleInvalidRegex() {
2479                 static $rxTc = false;
2480                 if ( !$rxTc ) {
2481                         # Matching titles will be held as illegal.
2482                         $rxTc = '/' .
2483                                 # Any character not allowed is forbidden...
2484                                 '[^' . Title::legalChars() . ']' .
2485                                 # URL percent encoding sequences interfere with the ability
2486                                 # to round-trip titles -- you can't link to them consistently.
2487                                 '|%[0-9A-Fa-f]{2}' .
2488                                 # XML/HTML character references produce similar issues.
2489                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2490                                 '|&#[0-9]+;' .
2491                                 '|&#x[0-9A-Fa-f]+;' .
2492                                 '/S';
2493                 }
2494
2495                 return $rxTc;
2496         }
2497
2498         /**
2499          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2500          *
2501          * @param $text string containing title to capitalize
2502          * @param $ns int namespace index, defaults to NS_MAIN
2503          * @return String containing capitalized title
2504          */
2505         public static function capitalize( $text, $ns = NS_MAIN ) {
2506                 global $wgContLang;
2507
2508                 if ( MWNamespace::isCapitalized( $ns ) ) {
2509                         return $wgContLang->ucfirst( $text );
2510                 } else {
2511                         return $text;
2512                 }
2513         }
2514
2515         /**
2516          * Secure and split - main initialisation function for this object
2517          *
2518          * Assumes that mDbkeyform has been set, and is urldecoded
2519          * and uses underscores, but not otherwise munged.  This function
2520          * removes illegal characters, splits off the interwiki and
2521          * namespace prefixes, sets the other forms, and canonicalizes
2522          * everything.
2523          *
2524          * @return \type{\bool} true on success
2525          */
2526         private function secureAndSplit() {
2527                 global $wgContLang, $wgLocalInterwiki;
2528
2529                 # Initialisation
2530                 $rxTc = self::getTitleInvalidRegex();
2531
2532                 $this->mInterwiki = $this->mFragment = '';
2533                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2534
2535                 $dbkey = $this->mDbkeyform;
2536
2537                 # Strip Unicode bidi override characters.
2538                 # Sometimes they slip into cut-n-pasted page titles, where the
2539                 # override chars get included in list displays.
2540                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2541
2542                 # Clean up whitespace
2543                 # Note: use of the /u option on preg_replace here will cause
2544                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2545                 # conveniently disabling them.
2546                 #
2547                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2548                 $dbkey = trim( $dbkey, '_' );
2549
2550                 if ( $dbkey == '' ) {
2551                         return false;
2552                 }
2553
2554                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2555                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2556                         return false;
2557                 }
2558
2559                 $this->mDbkeyform = $dbkey;
2560
2561                 # Initial colon indicates main namespace rather than specified default
2562                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2563                 if ( ':' == $dbkey { 0 } ) {
2564                         $this->mNamespace = NS_MAIN;
2565                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2566                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2567                 }
2568
2569                 # Namespace or interwiki prefix
2570                 $firstPass = true;
2571                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2572                 do {
2573                         $m = array();
2574                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2575                                 $p = $m[1];
2576                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2577                                         # Ordinary namespace
2578                                         $dbkey = $m[2];
2579                                         $this->mNamespace = $ns;
2580                                         # For Talk:X pages, check if X has a "namespace" prefix
2581                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2582                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2583                                                         return false; # Disallow Talk:File:x type titles...
2584                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2585                                                         return false; # Disallow Talk:Interwiki:x type titles...
2586                                                 }
2587                                         }
2588                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2589                                         if ( !$firstPass ) {
2590                                                 # Can't make a local interwiki link to an interwiki link.
2591                                                 # That's just crazy!
2592                                                 return false;
2593                                         }
2594
2595                                         # Interwiki link
2596                                         $dbkey = $m[2];
2597                                         $this->mInterwiki = $wgContLang->lc( $p );
2598
2599                                         # Redundant interwiki prefix to the local wiki
2600                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2601                                                 if ( $dbkey == '' ) {
2602                                                         # Can't have an empty self-link
2603                                                         return false;
2604                                                 }
2605                                                 $this->mInterwiki = '';
2606                                                 $firstPass = false;
2607                                                 # Do another namespace split...
2608                                                 continue;
2609                                         }
2610
2611                                         # If there's an initial colon after the interwiki, that also
2612                                         # resets the default namespace
2613                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2614                                                 $this->mNamespace = NS_MAIN;
2615                                                 $dbkey = substr( $dbkey, 1 );
2616                                         }
2617                                 }
2618                                 # If there's no recognized interwiki or namespace,
2619                                 # then let the colon expression be part of the title.
2620                         }
2621                         break;
2622                 } while ( true );
2623
2624                 # We already know that some pages won't be in the database!
2625                 #
2626                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2627                         $this->mArticleID = 0;
2628                 }
2629                 $fragment = strstr( $dbkey, '#' );
2630                 if ( false !== $fragment ) {
2631                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2632                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2633                         # remove whitespace again: prevents "Foo_bar_#"
2634                         # becoming "Foo_bar_"
2635                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2636                 }
2637
2638                 # Reject illegal characters.
2639                 #
2640                 if ( preg_match( $rxTc, $dbkey ) ) {
2641                         return false;
2642                 }
2643
2644                 /**
2645                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2646                  * reachable due to the way web browsers deal with 'relative' URLs.
2647                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2648                  */
2649                 if ( strpos( $dbkey, '.' ) !== false &&
2650                      ( $dbkey === '.' || $dbkey === '..' ||
2651                        strpos( $dbkey, './' ) === 0  ||
2652                        strpos( $dbkey, '../' ) === 0 ||
2653                        strpos( $dbkey, '/./' ) !== false ||
2654                        strpos( $dbkey, '/../' ) !== false  ||
2655                        substr( $dbkey, -2 ) == '/.' ||
2656                        substr( $dbkey, -3 ) == '/..' ) )
2657                 {
2658                         return false;
2659                 }
2660
2661                 /**
2662                  * Magic tilde sequences? Nu-uh!
2663                  */
2664                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2665                         return false;
2666                 }
2667
2668                 /**
2669                  * Limit the size of titles to 255 bytes.
2670                  * This is typically the size of the underlying database field.
2671                  * We make an exception for special pages, which don't need to be stored
2672                  * in the database, and may edge over 255 bytes due to subpage syntax
2673                  * for long titles, e.g. [[Special:Block/Long name]]
2674                  */
2675                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2676                   strlen( $dbkey ) > 512 )
2677                 {
2678                         return false;
2679                 }
2680
2681                 /**
2682                  * Normally, all wiki links are forced to have
2683                  * an initial capital letter so [[foo]] and [[Foo]]
2684                  * point to the same place.
2685                  *
2686                  * Don't force it for interwikis, since the other
2687                  * site might be case-sensitive.
2688                  */
2689                 $this->mUserCaseDBKey = $dbkey;
2690                 if ( $this->mInterwiki == '' ) {
2691                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2692                 }
2693
2694                 /**
2695                  * Can't make a link to a namespace alone...
2696                  * "empty" local links can only be self-links
2697                  * with a fragment identifier.
2698                  */
2699                 if ( $dbkey == '' &&
2700                         $this->mInterwiki == '' &&
2701                         $this->mNamespace != NS_MAIN ) {
2702                         return false;
2703                 }
2704                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2705                 // IP names are not allowed for accounts, and can only be referring to
2706                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2707                 // there are numerous ways to present the same IP. Having sp:contribs scan
2708                 // them all is silly and having some show the edits and others not is
2709                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2710                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2711                         IP::sanitizeIP( $dbkey ) : $dbkey;
2712                 // Any remaining initial :s are illegal.
2713                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2714                         return false;
2715                 }
2716
2717                 # Fill fields
2718                 $this->mDbkeyform = $dbkey;
2719                 $this->mUrlform = wfUrlencode( $dbkey );
2720
2721                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2722
2723                 return true;
2724         }
2725
2726         /**
2727          * Set the fragment for this title. Removes the first character from the
2728          * specified fragment before setting, so it assumes you're passing it with
2729          * an initial "#".
2730          *
2731          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2732          * Still in active use privately.
2733          *
2734          * @param $fragment \type{\string} text
2735          */
2736         public function setFragment( $fragment ) {
2737                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2738         }
2739
2740         /**
2741          * Get a Title object associated with the talk page of this article
2742          *
2743          * @return \type{Title} the object for the talk page
2744          */
2745         public function getTalkPage() {
2746                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2747         }
2748
2749         /**
2750          * Get a title object associated with the subject page of this
2751          * talk page
2752          *
2753          * @return \type{Title} the object for the subject page
2754          */
2755         public function getSubjectPage() {
2756                 // Is this the same title?
2757                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2758                 if ( $this->getNamespace() == $subjectNS ) {
2759                         return $this;
2760                 }
2761                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2762         }
2763
2764         /**
2765          * Get an array of Title objects linking to this Title
2766          * Also stores the IDs in the link cache.
2767          *
2768          * WARNING: do not use this function on arbitrary user-supplied titles!
2769          * On heavily-used templates it will max out the memory.
2770          *
2771          * @param $options Array: may be FOR UPDATE
2772          * @param $table String: table name
2773          * @param $prefix String: fields prefix
2774          * @return \type{\arrayof{Title}} the Title objects linking here
2775          */
2776         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2777                 $linkCache = LinkCache::singleton();
2778
2779                 if ( count( $options ) > 0 ) {
2780                         $db = wfGetDB( DB_MASTER );
2781                 } else {
2782                         $db = wfGetDB( DB_SLAVE );
2783                 }
2784
2785                 $res = $db->select(
2786                         array( 'page', $table ),
2787                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2788                         array(
2789                                 "{$prefix}_from=page_id",
2790                                 "{$prefix}_namespace" => $this->getNamespace(),
2791                                 "{$prefix}_title"     => $this->getDBkey() ),
2792                         __METHOD__,
2793                         $options
2794                 );
2795
2796                 $retVal = array();
2797                 if ( $db->numRows( $res ) ) {
2798                         foreach ( $res as $row ) {
2799                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2800                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2801                                         $retVal[] = $titleObj;
2802                                 }
2803                         }
2804                 }
2805                 return $retVal;
2806         }
2807
2808         /**
2809          * Get an array of Title objects using this Title as a template
2810          * Also stores the IDs in the link cache.
2811          *
2812          * WARNING: do not use this function on arbitrary user-supplied titles!
2813          * On heavily-used templates it will max out the memory.
2814          *
2815          * @param $options Array: may be FOR UPDATE
2816          * @return \type{\arrayof{Title}} the Title objects linking here
2817          */
2818         public function getTemplateLinksTo( $options = array() ) {
2819                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2820         }
2821
2822         /**
2823          * Get an array of Title objects referring to non-existent articles linked from this page
2824          *
2825          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2826          * @return \type{\arrayof{Title}} the Title objects
2827          */
2828         public function getBrokenLinksFrom() {
2829                 if ( $this->getArticleId() == 0 ) {
2830                         # All links from article ID 0 are false positives
2831                         return array();
2832                 }
2833
2834                 $dbr = wfGetDB( DB_SLAVE );
2835                 $res = $dbr->select(
2836                         array( 'page', 'pagelinks' ),
2837                         array( 'pl_namespace', 'pl_title' ),
2838                         array(
2839                                 'pl_from' => $this->getArticleId(),
2840                                 'page_namespace IS NULL'
2841                         ),
2842                         __METHOD__, array(),
2843                         array(
2844                                 'page' => array(
2845                                         'LEFT JOIN',
2846                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2847                                 )
2848                         )
2849                 );
2850
2851                 $retVal = array();
2852                 foreach ( $res as $row ) {
2853                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2854                 }
2855                 return $retVal;
2856         }
2857
2858
2859         /**
2860          * Get a list of URLs to purge from the Squid cache when this
2861          * page changes
2862          *
2863          * @return \type{\arrayof{\string}} the URLs
2864          */
2865         public function getSquidURLs() {
2866                 global $wgContLang;
2867
2868                 $urls = array(
2869                         $this->getInternalURL(),
2870                         $this->getInternalURL( 'action=history' )
2871                 );
2872
2873                 // purge variant urls as well
2874                 if ( $wgContLang->hasVariants() ) {
2875                         $variants = $wgContLang->getVariants();
2876                         foreach ( $variants as $vCode ) {
2877                                 $urls[] = $this->getInternalURL( '', $vCode );
2878                         }
2879                 }
2880
2881                 return $urls;
2882         }
2883
2884         /**
2885          * Purge all applicable Squid URLs
2886          */
2887         public function purgeSquid() {
2888                 global $wgUseSquid;
2889                 if ( $wgUseSquid ) {
2890                         $urls = $this->getSquidURLs();
2891                         $u = new SquidUpdate( $urls );
2892                         $u->doUpdate();
2893                 }
2894         }
2895
2896         /**
2897          * Move this page without authentication
2898          *
2899          * @param $nt \type{Title} the new page Title
2900          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2901          */
2902         public function moveNoAuth( &$nt ) {
2903                 return $this->moveTo( $nt, false );
2904         }
2905
2906         /**
2907          * Check whether a given move operation would be valid.
2908          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2909          *
2910          * @param $nt \type{Title} the new title
2911          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2912          *  should be checked
2913          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2914          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2915          */
2916         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2917                 global $wgUser;
2918
2919                 $errors = array();
2920                 if ( !$nt ) {
2921                         // Normally we'd add this to $errors, but we'll get
2922                         // lots of syntax errors if $nt is not an object
2923                         return array( array( 'badtitletext' ) );
2924                 }
2925                 if ( $this->equals( $nt ) ) {
2926                         $errors[] = array( 'selfmove' );
2927                 }
2928                 if ( !$this->isMovable() ) {
2929                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2930                 }
2931                 if ( $nt->getInterwiki() != '' ) {
2932                         $errors[] = array( 'immobile-target-namespace-iw' );
2933                 }
2934                 if ( !$nt->isMovable() ) {
2935                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2936                 }
2937
2938                 $oldid = $this->getArticleID();
2939                 $newid = $nt->getArticleID();
2940
2941                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2942                         $errors[] = array( 'articleexists' );
2943                 }
2944                 if ( ( $this->getDBkey() == '' ) ||
2945                          ( !$oldid ) ||
2946                      ( $nt->getDBkey() == '' ) ) {
2947                         $errors[] = array( 'badarticleerror' );
2948                 }
2949
2950                 // Image-specific checks
2951                 if ( $this->getNamespace() == NS_FILE ) {
2952                         if ( $nt->getNamespace() != NS_FILE ) {
2953                                 $errors[] = array( 'imagenocrossnamespace' );
2954                         }
2955                         $file = wfLocalFile( $this );
2956                         if ( $file->exists() ) {
2957                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2958                                         $errors[] = array( 'imageinvalidfilename' );
2959                                 }
2960                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2961                                         $errors[] = array( 'imagetypemismatch' );
2962                                 }
2963                         }
2964                         $destfile = wfLocalFile( $nt );
2965                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2966                                 $errors[] = array( 'file-exists-sharedrepo' );
2967                         }
2968                 }
2969
2970                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2971                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2972                 }
2973
2974                 if ( $auth ) {
2975                         $errors = wfMergeErrorArrays( $errors,
2976                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2977                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2978                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2979                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2980                 }
2981
2982                 $match = EditPage::matchSummarySpamRegex( $reason );
2983                 if ( $match !== false ) {
2984                         // This is kind of lame, won't display nice
2985                         $errors[] = array( 'spamprotectiontext' );
2986                 }
2987
2988                 $err = null;
2989                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2990                         $errors[] = array( 'hookaborted', $err );
2991                 }
2992
2993                 # The move is allowed only if (1) the target doesn't exist, or
2994                 # (2) the target is a redirect to the source, and has no history
2995                 # (so we can undo bad moves right after they're done).
2996
2997                 if ( 0 != $newid ) { # Target exists; check for validity
2998                         if ( !$this->isValidMoveTarget( $nt ) ) {
2999                                 $errors[] = array( 'articleexists' );
3000                         }
3001                 } else {
3002                         $tp = $nt->getTitleProtection();
3003                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3004                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3005                                 $errors[] = array( 'cantmove-titleprotected' );
3006                         }
3007                 }
3008                 if ( empty( $errors ) ) {
3009                         return true;
3010                 }
3011                 return $errors;
3012         }
3013
3014         /**
3015          * Move a title to a new location
3016          *
3017          * @param $nt \type{Title} the new title
3018          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3019          *  should be checked
3020          * @param $reason \type{\string} The reason for the move
3021          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3022          *  Ignored if the user doesn't have the suppressredirect right.
3023          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3024          */
3025         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3026                 global $wgContLang;
3027
3028                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3029                 if ( is_array( $err ) ) {
3030                         return $err;
3031                 }
3032
3033                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3034                 $dbw = wfGetDB( DB_MASTER );
3035                 if ( $this->getNamespace() == NS_FILE ) {
3036                         $file = wfLocalFile( $this );
3037                         if ( $file->exists() ) {
3038                                 $status = $file->move( $nt );
3039                                 if ( !$status->isOk() ) {
3040                                         return $status->getErrorsArray();
3041                                 }
3042                         }
3043                 }
3044
3045                 $pageid = $this->getArticleID();
3046                 $protected = $this->isProtected();
3047                 if ( $nt->exists() ) {
3048                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3049                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3050                 } else { # Target didn't exist, do normal move.
3051                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3052                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3053                 }
3054
3055                 if ( is_array( $err ) ) {
3056                         return $err;
3057                 }
3058                 $redirid = $this->getArticleID();
3059
3060                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3061                 // cl_timestamp, which may disturb time-based lists on some sites.
3062                 $prefix = $dbw->selectField(
3063                         'categorylinks',
3064                         'cl_sortkey_prefix',
3065                         array( 'cl_from' => $pageid ),
3066                         __METHOD__
3067                 );
3068                 $dbw->update( 'categorylinks',
3069                         array(
3070                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3071                                 'cl_timestamp=cl_timestamp' ),
3072                         array( 'cl_from' => $pageid ),
3073                         __METHOD__ );
3074
3075                 if ( $protected ) {
3076                         # Protect the redirect title as the title used to be...
3077                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3078                                 array(
3079                                         'pr_page'    => $redirid,
3080                                         'pr_type'    => 'pr_type',
3081                                         'pr_level'   => 'pr_level',
3082                                         'pr_cascade' => 'pr_cascade',
3083                                         'pr_user'    => 'pr_user',
3084                                         'pr_expiry'  => 'pr_expiry'
3085                                 ),
3086                                 array( 'pr_page' => $pageid ),
3087                                 __METHOD__,
3088                                 array( 'IGNORE' )
3089                         );
3090                         # Update the protection log
3091                         $log = new LogPage( 'protect' );
3092                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3093                         if ( $reason ) {
3094                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3095                         }
3096                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3097                 }
3098
3099                 # Update watchlists
3100                 $oldnamespace = $this->getNamespace() & ~1;
3101                 $newnamespace = $nt->getNamespace() & ~1;
3102                 $oldtitle = $this->getDBkey();
3103                 $newtitle = $nt->getDBkey();
3104
3105                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3106                         WatchedItem::duplicateEntries( $this, $nt );
3107                 }
3108
3109                 # Update search engine
3110                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3111                 $u->doUpdate();
3112                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3113                 $u->doUpdate();
3114
3115                 # Update site_stats
3116                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3117                         # No longer a content page
3118                         # Not viewed, edited, removing
3119                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3120                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3121                         # Now a content page
3122                         # Not viewed, edited, adding
3123                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3124                 } elseif ( $pageCountChange ) {
3125                         # Redirect added
3126                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3127                 } else {
3128                         # Nothing special
3129                         $u = false;
3130                 }
3131                 if ( $u ) {
3132                         $u->doUpdate();
3133                 }
3134                 # Update message cache for interface messages
3135                 global $wgMessageCache;
3136                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3137                         # @bug 17860: old article can be deleted, if this the case,
3138                         # delete it from message cache
3139                         if ( $this->getArticleID() === 0 ) {
3140                                 $wgMessageCache->replace( $this->getDBkey(), false );
3141                         } else {
3142                                 $oldarticle = new Article( $this );
3143                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3144                         }
3145                 }
3146                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3147                         $newarticle = new Article( $nt );
3148                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3149                 }
3150
3151                 global $wgUser;
3152                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3153                 return true;
3154         }
3155
3156         /**
3157          * Move page to a title which is at present a redirect to the
3158          * source page
3159          *
3160          * @param $nt \type{Title} the page to move to, which should currently
3161          *  be a redirect
3162          * @param $reason \type{\string} The reason for the move
3163          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3164          *  Ignored if the user doesn't have the suppressredirect right
3165          */
3166         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3167                 global $wgUseSquid, $wgUser, $wgContLang;
3168
3169                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3170
3171                 if ( $reason ) {
3172                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3173                 }
3174                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3175                 $comment = $wgContLang->truncate( $comment, 250 );
3176
3177                 $now = wfTimestampNow();
3178                 $newid = $nt->getArticleID();
3179                 $oldid = $this->getArticleID();
3180                 $latest = $this->getLatestRevID();
3181
3182                 $dbw = wfGetDB( DB_MASTER );
3183
3184                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3185                 $newns = $nt->getNamespace();
3186                 $newdbk = $nt->getDBkey();
3187
3188                 # Delete the old redirect. We don't save it to history since
3189                 # by definition if we've got here it's rather uninteresting.
3190                 # We have to remove it so that the next step doesn't trigger
3191                 # a conflict on the unique namespace+title index...
3192                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3193                 if ( !$dbw->cascadingDeletes() ) {
3194                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3195                         global $wgUseTrackbacks;
3196                         if ( $wgUseTrackbacks ) {
3197                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3198                         }
3199                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3200                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3201                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3202                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3203                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3204                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3205                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3206                 }
3207                 // If the redirect was recently created, it may have an entry in recentchanges still
3208                 $dbw->delete( 'recentchanges',
3209                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3210                         __METHOD__
3211                 );
3212
3213                 # Save a null revision in the page's history notifying of the move
3214                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3215                 $nullRevId = $nullRevision->insertOn( $dbw );
3216
3217                 $article = new Article( $this );
3218                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3219
3220                 # Change the name of the target page:
3221                 $dbw->update( 'page',
3222                         /* SET */ array(
3223                                 'page_touched'   => $dbw->timestamp( $now ),
3224                                 'page_namespace' => $nt->getNamespace(),
3225                                 'page_title'     => $nt->getDBkey(),
3226                                 'page_latest'    => $nullRevId,
3227                         ),
3228                         /* WHERE */ array( 'page_id' => $oldid ),
3229                         __METHOD__
3230                 );
3231                 $nt->resetArticleID( $oldid );
3232
3233                 # Recreate the redirect, this time in the other direction.
3234                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3235                         $mwRedir = MagicWord::get( 'redirect' );
3236                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3237                         $redirectArticle = new Article( $this );
3238                         $newid = $redirectArticle->insertOn( $dbw );
3239                         $redirectRevision = new Revision( array(
3240                                 'page'    => $newid,
3241                                 'comment' => $comment,
3242                                 'text'    => $redirectText ) );
3243                         $redirectRevision->insertOn( $dbw );
3244                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3245
3246                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3247
3248                         # Now, we record the link from the redirect to the new title.
3249                         # It should have no other outgoing links...
3250                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3251                         $dbw->insert( 'pagelinks',
3252                                 array(
3253                                         'pl_from'      => $newid,
3254                                         'pl_namespace' => $nt->getNamespace(),
3255                                         'pl_title'     => $nt->getDBkey() ),
3256                                 __METHOD__ );
3257                         $redirectSuppressed = false;
3258                 } else {
3259                         $this->resetArticleID( 0 );
3260                         $redirectSuppressed = true;
3261                 }
3262
3263                 # Log the move
3264                 $log = new LogPage( 'move' );
3265                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3266
3267                 # Purge squid
3268                 if ( $wgUseSquid ) {
3269                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3270                         $u = new SquidUpdate( $urls );
3271                         $u->doUpdate();
3272                 }
3273
3274         }
3275
3276         /**
3277          * Move page to non-existing title.
3278          *
3279          * @param $nt \type{Title} the new Title
3280          * @param $reason \type{\string} The reason for the move
3281          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3282          *  Ignored if the user doesn't have the suppressredirect right
3283          */
3284         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3285                 global $wgUser, $wgContLang;
3286
3287                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3288                 if ( $reason ) {
3289                         $comment .= wfMsgExt( 'colon-separator',
3290                                 array( 'escapenoentities', 'content' ) );
3291                         $comment .= $reason;
3292                 }
3293                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3294                 $comment = $wgContLang->truncate( $comment, 250 );
3295
3296                 $newid = $nt->getArticleID();
3297                 $oldid = $this->getArticleID();
3298                 $latest = $this->getLatestRevId();
3299
3300                 $dbw = wfGetDB( DB_MASTER );
3301                 $now = $dbw->timestamp();
3302
3303                 # Save a null revision in the page's history notifying of the move
3304                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3305                 if ( !is_object( $nullRevision ) ) {
3306                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3307                 }
3308                 $nullRevId = $nullRevision->insertOn( $dbw );
3309
3310                 $article = new Article( $this );
3311                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3312
3313                 # Rename page entry
3314                 $dbw->update( 'page',
3315                         /* SET */ array(
3316                                 'page_touched'   => $now,
3317                                 'page_namespace' => $nt->getNamespace(),
3318                                 'page_title'     => $nt->getDBkey(),
3319                                 'page_latest'    => $nullRevId,
3320                         ),
3321                         /* WHERE */ array( 'page_id' => $oldid ),
3322                         __METHOD__
3323                 );
3324                 $nt->resetArticleID( $oldid );
3325
3326                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3327                         # Insert redirect
3328                         $mwRedir = MagicWord::get( 'redirect' );
3329                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3330                         $redirectArticle = new Article( $this );
3331                         $newid = $redirectArticle->insertOn( $dbw );
3332                         $redirectRevision = new Revision( array(
3333                                 'page'    => $newid,
3334                                 'comment' => $comment,
3335                                 'text'    => $redirectText ) );
3336                         $redirectRevision->insertOn( $dbw );
3337                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3338
3339                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3340
3341                         # Record the just-created redirect's linking to the page
3342                         $dbw->insert( 'pagelinks',
3343                                 array(
3344                                         'pl_from'      => $newid,
3345                                         'pl_namespace' => $nt->getNamespace(),
3346                                         'pl_title'     => $nt->getDBkey() ),
3347                                 __METHOD__ );
3348                         $redirectSuppressed = false;
3349                 } else {
3350                         $this->resetArticleID( 0 );
3351                         $redirectSuppressed = true;
3352                 }
3353
3354                 # Log the move
3355                 $log = new LogPage( 'move' );
3356                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3357
3358                 # Purge caches as per article creation
3359                 Article::onArticleCreate( $nt );
3360
3361                 # Purge old title from squid
3362                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3363                 $this->purgeSquid();
3364         }
3365
3366         /**
3367          * Move this page's subpages to be subpages of $nt
3368          *
3369          * @param $nt Title Move target
3370          * @param $auth bool Whether $wgUser's permissions should be checked
3371          * @param $reason string The reason for the move
3372          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3373          *  Ignored if the user doesn't have the 'suppressredirect' right
3374          * @return mixed array with old page titles as keys, and strings (new page titles) or
3375          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3376          */
3377         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3378                 global $wgMaximumMovedPages;
3379                 // Check permissions
3380                 if ( !$this->userCan( 'move-subpages' ) ) {
3381                         return array( 'cant-move-subpages' );
3382                 }
3383                 // Do the source and target namespaces support subpages?
3384                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3385                         return array( 'namespace-nosubpages',
3386                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3387                 }
3388                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3389                         return array( 'namespace-nosubpages',
3390                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3391                 }
3392
3393                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3394                 $retval = array();
3395                 $count = 0;
3396                 foreach ( $subpages as $oldSubpage ) {
3397                         $count++;
3398                         if ( $count > $wgMaximumMovedPages ) {
3399                                 $retval[$oldSubpage->getPrefixedTitle()] =
3400                                                 array( 'movepage-max-pages',
3401                                                         $wgMaximumMovedPages );
3402                                 break;
3403                         }
3404
3405                         // We don't know whether this function was called before
3406                         // or after moving the root page, so check both
3407                         // $this and $nt
3408                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3409                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3410                         {
3411                                 // When moving a page to a subpage of itself,
3412                                 // don't move it twice
3413                                 continue;
3414                         }
3415                         $newPageName = preg_replace(
3416                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3417                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3418                                         $oldSubpage->getDBkey() );
3419                         if ( $oldSubpage->isTalkPage() ) {
3420                                 $newNs = $nt->getTalkPage()->getNamespace();
3421                         } else {
3422                                 $newNs = $nt->getSubjectPage()->getNamespace();
3423                         }
3424                         # Bug 14385: we need makeTitleSafe because the new page names may
3425                         # be longer than 255 characters.
3426                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3427
3428                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3429                         if ( $success === true ) {
3430                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3431                         } else {
3432                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3433                         }
3434                 }
3435                 return $retval;
3436         }
3437
3438         /**
3439          * Checks if this page is just a one-rev redirect.
3440          * Adds lock, so don't use just for light purposes.
3441          *
3442          * @return \type{\bool}
3443          */
3444         public function isSingleRevRedirect() {
3445                 $dbw = wfGetDB( DB_MASTER );
3446                 # Is it a redirect?
3447                 $row = $dbw->selectRow( 'page',
3448                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3449                         $this->pageCond(),
3450                         __METHOD__,
3451                         array( 'FOR UPDATE' )
3452                 );
3453                 # Cache some fields we may want
3454                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3455                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3456                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3457                 if ( !$this->mRedirect ) {
3458                         return false;
3459                 }
3460                 # Does the article have a history?
3461                 $row = $dbw->selectField( array( 'page', 'revision' ),
3462                         'rev_id',
3463                         array( 'page_namespace' => $this->getNamespace(),
3464                                 'page_title' => $this->getDBkey(),
3465                                 'page_id=rev_page',
3466                                 'page_latest != rev_id'
3467                         ),
3468                         __METHOD__,
3469                         array( 'FOR UPDATE' )
3470                 );
3471                 # Return true if there was no history
3472                 return ( $row === false );
3473         }
3474
3475         /**
3476          * Checks if $this can be moved to a given Title
3477          * - Selects for update, so don't call it unless you mean business
3478          *
3479          * @param $nt \type{Title} the new title to check
3480          * @return \type{\bool} TRUE or FALSE
3481          */
3482         public function isValidMoveTarget( $nt ) {
3483                 # Is it an existing file?
3484                 if ( $nt->getNamespace() == NS_FILE ) {
3485                         $file = wfLocalFile( $nt );
3486                         if ( $file->exists() ) {
3487                                 wfDebug( __METHOD__ . ": file exists\n" );
3488                                 return false;
3489                         }
3490                 }
3491                 # Is it a redirect with no history?
3492                 if ( !$nt->isSingleRevRedirect() ) {
3493                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3494                         return false;
3495                 }
3496                 # Get the article text
3497                 $rev = Revision::newFromTitle( $nt );
3498                 $text = $rev->getText();
3499                 # Does the redirect point to the source?
3500                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3501                 $m = array();
3502                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3503                         $redirTitle = Title::newFromText( $m[1] );
3504                         if ( !is_object( $redirTitle ) ||
3505                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3506                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3507                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3508                                 return false;
3509                         }
3510                 } else {
3511                         # Fail safe
3512                         wfDebug( __METHOD__ . ": failsafe\n" );
3513                         return false;
3514                 }
3515                 return true;
3516         }
3517
3518         /**
3519          * Can this title be added to a user's watchlist?
3520          *
3521          * @return \type{\bool} TRUE or FALSE
3522          */
3523         public function isWatchable() {
3524                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3525         }
3526
3527         /**
3528          * Get categories to which this Title belongs and return an array of
3529          * categories' names.
3530          *
3531          * @return \type{\array} array an array of parents in the form:
3532          *      $parent => $currentarticle
3533          */
3534         public function getParentCategories() {
3535                 global $wgContLang;
3536
3537                 $titlekey = $this->getArticleId();
3538                 $dbr = wfGetDB( DB_SLAVE );
3539                 $categorylinks = $dbr->tableName( 'categorylinks' );
3540
3541                 # NEW SQL
3542                 $sql = "SELECT * FROM $categorylinks"
3543                      . " WHERE cl_from='$titlekey'"
3544                          . " AND cl_from <> '0'"
3545                          . " ORDER BY cl_sortkey";
3546
3547                 $res = $dbr->query( $sql );
3548                 $data = array();
3549
3550                 if ( $dbr->numRows( $res ) > 0 ) {
3551                         foreach ( $res as $row ) {
3552                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3553                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3554                         }
3555                 }
3556                 return $data;
3557         }
3558
3559         /**
3560          * Get a tree of parent categories
3561          *
3562          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3563          * @return \type{\array} Tree of parent categories
3564          */
3565         public function getParentCategoryTree( $children = array() ) {
3566                 $stack = array();
3567                 $parents = $this->getParentCategories();
3568
3569                 if ( $parents ) {
3570                         foreach ( $parents as $parent => $current ) {
3571                                 if ( array_key_exists( $parent, $children ) ) {
3572                                         # Circular reference
3573                                         $stack[$parent] = array();
3574                                 } else {
3575                                         $nt = Title::newFromText( $parent );
3576                                         if ( $nt ) {
3577                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3578                                         }
3579                                 }
3580                         }
3581                 }
3582
3583                 return $stack;
3584         }
3585
3586
3587         /**
3588          * Get an associative array for selecting this title from
3589          * the "page" table
3590          *
3591          * @return \type{\array} Selection array
3592          */
3593         public function pageCond() {
3594                 if ( $this->mArticleID > 0 ) {
3595                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3596                         return array( 'page_id' => $this->mArticleID );
3597                 } else {
3598                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3599                 }
3600         }
3601
3602         /**
3603          * Get the revision ID of the previous revision
3604          *
3605          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3606          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3607          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3608          */
3609         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3610                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3611                 return $db->selectField( 'revision', 'rev_id',
3612                         array(
3613                                 'rev_page' => $this->getArticleId( $flags ),
3614                                 'rev_id < ' . intval( $revId )
3615                         ),
3616                         __METHOD__,
3617                         array( 'ORDER BY' => 'rev_id DESC' )
3618                 );
3619         }
3620
3621         /**
3622          * Get the revision ID of the next revision
3623          *
3624          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3625          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3626          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3627          */
3628         public function getNextRevisionID( $revId, $flags = 0 ) {
3629                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3630                 return $db->selectField( 'revision', 'rev_id',
3631                         array(
3632                                 'rev_page' => $this->getArticleId( $flags ),
3633                                 'rev_id > ' . intval( $revId )
3634                         ),
3635                         __METHOD__,
3636                         array( 'ORDER BY' => 'rev_id' )
3637                 );
3638         }
3639
3640         /**
3641          * Get the first revision of the page
3642          *
3643          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3644          * @return Revision (or NULL if page doesn't exist)
3645          */
3646         public function getFirstRevision( $flags = 0 ) {
3647                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3648                 $pageId = $this->getArticleId( $flags );
3649                 if ( !$pageId ) {
3650                         return null;
3651                 }
3652                 $row = $db->selectRow( 'revision', '*',
3653                         array( 'rev_page' => $pageId ),
3654                         __METHOD__,
3655                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3656                 );
3657                 if ( !$row ) {
3658                         return null;
3659                 } else {
3660                         return new Revision( $row );
3661                 }
3662         }
3663
3664         /**
3665          * Check if this is a new page
3666          *
3667          * @return bool
3668          */
3669         public function isNewPage() {
3670                 $dbr = wfGetDB( DB_SLAVE );
3671                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3672         }
3673
3674         /**
3675          * Get the oldest revision timestamp of this page
3676          *
3677          * @return String: MW timestamp
3678          */
3679         public function getEarliestRevTime() {
3680                 $dbr = wfGetDB( DB_SLAVE );
3681                 if ( $this->exists() ) {
3682                         $min = $dbr->selectField( 'revision',
3683                                 'MIN(rev_timestamp)',
3684                                 array( 'rev_page' => $this->getArticleId() ),
3685                                 __METHOD__ );
3686                         return wfTimestampOrNull( TS_MW, $min );
3687                 }
3688                 return null;
3689         }
3690
3691         /**
3692          * Get the number of revisions between the given revision IDs.
3693          * Used for diffs and other things that really need it.
3694          *
3695          * @param $old \type{\int} Revision ID.
3696          * @param $new \type{\int} Revision ID.
3697          * @return \type{\int} Number of revisions between these IDs.
3698          */
3699         public function countRevisionsBetween( $old, $new ) {
3700                 $dbr = wfGetDB( DB_SLAVE );
3701                 return (int)$dbr->selectField( 'revision', 'count(*)',
3702                         'rev_page = ' . intval( $this->getArticleId() ) .
3703                         ' AND rev_id > ' . intval( $old ) .
3704                         ' AND rev_id < ' . intval( $new ),
3705                         __METHOD__
3706                 );
3707         }
3708
3709         /**
3710          * Compare with another title.
3711          *
3712          * @param $title \type{Title}
3713          * @return \type{\bool} TRUE or FALSE
3714          */
3715         public function equals( Title $title ) {
3716                 // Note: === is necessary for proper matching of number-like titles.
3717                 return $this->getInterwiki() === $title->getInterwiki()
3718                         && $this->getNamespace() == $title->getNamespace()
3719                         && $this->getDBkey() === $title->getDBkey();
3720         }
3721
3722         /**
3723          * Callback for usort() to do title sorts by (namespace, title)
3724          *
3725          * @return Integer: result of string comparison, or namespace comparison
3726          */
3727         public static function compare( $a, $b ) {
3728                 if ( $a->getNamespace() == $b->getNamespace() ) {
3729                         return strcmp( $a->getText(), $b->getText() );
3730                 } else {
3731                         return $a->getNamespace() - $b->getNamespace();
3732                 }
3733         }
3734
3735         /**
3736          * Return a string representation of this title
3737          *
3738          * @return \type{\string} String representation of this title
3739          */
3740         public function __toString() {
3741                 return $this->getPrefixedText();
3742         }
3743
3744         /**
3745          * Check if page exists.  For historical reasons, this function simply
3746          * checks for the existence of the title in the page table, and will
3747          * thus return false for interwiki links, special pages and the like.
3748          * If you want to know if a title can be meaningfully viewed, you should
3749          * probably call the isKnown() method instead.
3750          *
3751          * @return \type{\bool}
3752          */
3753         public function exists() {
3754                 return $this->getArticleId() != 0;
3755         }
3756
3757         /**
3758          * Should links to this title be shown as potentially viewable (i.e. as
3759          * "bluelinks"), even if there's no record by this title in the page
3760          * table?
3761          *
3762          * This function is semi-deprecated for public use, as well as somewhat
3763          * misleadingly named.  You probably just want to call isKnown(), which
3764          * calls this function internally.
3765          *
3766          * (ISSUE: Most of these checks are cheap, but the file existence check
3767          * can potentially be quite expensive.  Including it here fixes a lot of
3768          * existing code, but we might want to add an optional parameter to skip
3769          * it and any other expensive checks.)
3770          *
3771          * @return \type{\bool}
3772          */
3773         public function isAlwaysKnown() {
3774                 if ( $this->mInterwiki != '' ) {
3775                         return true;  // any interwiki link might be viewable, for all we know
3776                 }
3777                 switch( $this->mNamespace ) {
3778                         case NS_MEDIA:
3779                         case NS_FILE:
3780                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3781                         case NS_SPECIAL:
3782                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3783                         case NS_MAIN:
3784                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3785                         case NS_MEDIAWIKI:
3786                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3787                                 // the full l10n of that language to be loaded. That takes much memory and
3788                                 // isn't needed. So we strip the language part away.
3789                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3790                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3791                         default:
3792                                 return false;
3793                 }
3794         }
3795
3796         /**
3797          * Does this title refer to a page that can (or might) be meaningfully
3798          * viewed?  In particular, this function may be used to determine if
3799          * links to the title should be rendered as "bluelinks" (as opposed to
3800          * "redlinks" to non-existent pages).
3801          *
3802          * @return \type{\bool}
3803          */
3804         public function isKnown() {
3805                 return $this->isAlwaysKnown() || $this->exists();
3806         }
3807
3808         /**
3809          * Does this page have source text?
3810          *
3811          * @return Boolean
3812          */
3813         public function hasSourceText() {
3814                 if ( $this->exists() ) {
3815                         return true;
3816                 }
3817
3818                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3819                         // If the page doesn't exist but is a known system message, default
3820                         // message content will be displayed, same for language subpages
3821                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3822                         // causes the full l10n of that language to be loaded. That takes much
3823                         // memory and isn't needed. So we strip the language part away.
3824                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3825                         return (bool)wfMsgWeirdKey( $basename );
3826                 }
3827
3828                 return false;
3829         }
3830
3831         /**
3832          * Is this in a namespace that allows actual pages?
3833          *
3834          * @return \type{\bool}
3835          * @internal note -- uses hardcoded namespace index instead of constants
3836          */
3837         public function canExist() {
3838                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3839         }
3840
3841         /**
3842          * Update page_touched timestamps and send squid purge messages for
3843          * pages linking to this title. May be sent to the job queue depending
3844          * on the number of links. Typically called on create and delete.
3845          */
3846         public function touchLinks() {
3847                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3848                 $u->doUpdate();
3849
3850                 if ( $this->getNamespace() == NS_CATEGORY ) {
3851                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3852                         $u->doUpdate();
3853                 }
3854         }
3855
3856         /**
3857          * Get the last touched timestamp
3858          *
3859          * @param $db DatabaseBase: optional db
3860          * @return \type{\string} Last touched timestamp
3861          */
3862         public function getTouched( $db = null ) {
3863                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3864                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3865                 return $touched;
3866         }
3867
3868         /**
3869          * Get the timestamp when this page was updated since the user last saw it.
3870          *
3871          * @param $user User
3872          * @return Mixed: string/null
3873          */
3874         public function getNotificationTimestamp( $user = null ) {
3875                 global $wgUser, $wgShowUpdatedMarker;
3876                 // Assume current user if none given
3877                 if ( !$user ) {
3878                         $user = $wgUser;
3879                 }
3880                 // Check cache first
3881                 $uid = $user->getId();
3882                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3883                         return $this->mNotificationTimestamp[$uid];
3884                 }
3885                 if ( !$uid || !$wgShowUpdatedMarker ) {
3886                         return $this->mNotificationTimestamp[$uid] = false;
3887                 }
3888                 // Don't cache too much!
3889                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3890                         $this->mNotificationTimestamp = array();
3891                 }
3892                 $dbr = wfGetDB( DB_SLAVE );
3893                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3894                         'wl_notificationtimestamp',
3895                         array( 'wl_namespace' => $this->getNamespace(),
3896                                 'wl_title' => $this->getDBkey(),
3897                                 'wl_user' => $user->getId()
3898                         ),
3899                         __METHOD__
3900                 );
3901                 return $this->mNotificationTimestamp[$uid];
3902         }
3903
3904         /**
3905          * Get the trackback URL for this page
3906          *
3907          * @return \type{\string} Trackback URL
3908          */
3909         public function trackbackURL() {
3910                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3911
3912                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3913                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3914         }
3915
3916         /**
3917          * Get the trackback RDF for this page
3918          *
3919          * @return \type{\string} Trackback RDF
3920          */
3921         public function trackbackRDF() {
3922                 $url = htmlspecialchars( $this->getFullURL() );
3923                 $title = htmlspecialchars( $this->getText() );
3924                 $tburl = $this->trackbackURL();
3925
3926                 // Autodiscovery RDF is placed in comments so HTML validator
3927                 // won't barf. This is a rather icky workaround, but seems
3928                 // frequently used by this kind of RDF thingy.
3929                 //
3930                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3931                 return "<!--
3932 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3933          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3934          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3935 <rdf:Description
3936    rdf:about=\"$url\"
3937    dc:identifier=\"$url\"
3938    dc:title=\"$title\"
3939    trackback:ping=\"$tburl\" />
3940 </rdf:RDF>
3941 -->";
3942         }
3943
3944         /**
3945          * Generate strings used for xml 'id' names in monobook tabs
3946          *
3947          * @param $prepend string defaults to 'nstab-'
3948          * @return \type{\string} XML 'id' name
3949          */
3950         public function getNamespaceKey( $prepend = 'nstab-' ) {
3951                 global $wgContLang;
3952                 // Gets the subject namespace if this title
3953                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3954                 // Checks if cononical namespace name exists for namespace
3955                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3956                         // Uses canonical namespace name
3957                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3958                 } else {
3959                         // Uses text of namespace
3960                         $namespaceKey = $this->getSubjectNsText();
3961                 }
3962                 // Makes namespace key lowercase
3963                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3964                 // Uses main
3965                 if ( $namespaceKey == '' ) {
3966                         $namespaceKey = 'main';
3967                 }
3968                 // Changes file to image for backwards compatibility
3969                 if ( $namespaceKey == 'file' ) {
3970                         $namespaceKey = 'image';
3971                 }
3972                 return $prepend . $namespaceKey;
3973         }
3974
3975         /**
3976          * Returns true if this is a special page.
3977          *
3978          * @return boolean
3979          */
3980         public function isSpecialPage() {
3981                 return $this->getNamespace() == NS_SPECIAL;
3982         }
3983
3984         /**
3985          * Returns true if this title resolves to the named special page
3986          *
3987          * @param $name \type{\string} The special page name
3988          * @return boolean
3989          */
3990         public function isSpecial( $name ) {
3991                 if ( $this->getNamespace() == NS_SPECIAL ) {
3992                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3993                         if ( $name == $thisName ) {
3994                                 return true;
3995                         }
3996                 }
3997                 return false;
3998         }
3999
4000         /**
4001          * If the Title refers to a special page alias which is not the local default,
4002          *
4003          * @return \type{Title} A new Title which points to the local default.
4004          *         Otherwise, returns $this.
4005          */
4006         public function fixSpecialName() {
4007                 if ( $this->getNamespace() == NS_SPECIAL ) {
4008                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4009                         if ( $canonicalName ) {
4010                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4011                                 if ( $localName != $this->mDbkeyform ) {
4012                                         return Title::makeTitle( NS_SPECIAL, $localName );
4013                                 }
4014                         }
4015                 }
4016                 return $this;
4017         }
4018
4019         /**
4020          * Is this Title in a namespace which contains content?
4021          * In other words, is this a content page, for the purposes of calculating
4022          * statistics, etc?
4023          *
4024          * @return \type{\bool}
4025          */
4026         public function isContentPage() {
4027                 return MWNamespace::isContent( $this->getNamespace() );
4028         }
4029
4030         /**
4031          * Get all extant redirects to this Title
4032          *
4033          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4034          *            NULL to consider all namespaces
4035          * @return \type{\arrayof{Title}} Redirects to this title
4036          */
4037         public function getRedirectsHere( $ns = null ) {
4038                 $redirs = array();
4039
4040                 $dbr = wfGetDB( DB_SLAVE );
4041                 $where = array(
4042                         'rd_namespace' => $this->getNamespace(),
4043                         'rd_title' => $this->getDBkey(),
4044                         'rd_from = page_id'
4045                 );
4046                 if ( !is_null( $ns ) ) {
4047                         $where['page_namespace'] = $ns;
4048                 }
4049
4050                 $res = $dbr->select(
4051                         array( 'redirect', 'page' ),
4052                         array( 'page_namespace', 'page_title' ),
4053                         $where,
4054                         __METHOD__
4055                 );
4056
4057                 foreach ( $res as $row ) {
4058                         $redirs[] = self::newFromRow( $row );
4059                 }
4060                 return $redirs;
4061         }
4062
4063         /**
4064          * Check if this Title is a valid redirect target
4065          *
4066          * @return \type{\bool}
4067          */
4068         public function isValidRedirectTarget() {
4069                 global $wgInvalidRedirectTargets;
4070
4071                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4072                 if ( $this->isSpecial( 'Userlogout' ) ) {
4073                         return false;
4074                 }
4075
4076                 foreach ( $wgInvalidRedirectTargets as $target ) {
4077                         if ( $this->isSpecial( $target ) ) {
4078                                 return false;
4079                         }
4080                 }
4081
4082                 return true;
4083         }
4084
4085         /**
4086          * Get a backlink cache object
4087          *
4088          * @return object BacklinkCache
4089          */
4090         function getBacklinkCache() {
4091                 if ( is_null( $this->mBacklinkCache ) ) {
4092                         $this->mBacklinkCache = new BacklinkCache( $this );
4093                 }
4094                 return $this->mBacklinkCache;
4095         }
4096
4097         /**
4098          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4099          * this page.
4100          *
4101          * @return Boolean
4102          */
4103         public function canUseNoindex() {
4104                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4105
4106                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4107                         ? $wgContentNamespaces
4108                         : $wgExemptFromUserRobotsControl;
4109
4110                 return !in_array( $this->mNamespace, $bannedNamespaces );
4111
4112         }
4113
4114         /**
4115          * Returns restriction types for the current Title
4116          *
4117          * @return array applicable restriction types
4118          */
4119         public function getRestrictionTypes() {
4120                 global $wgRestrictionTypes;
4121                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4122
4123                 if ( $this->getNamespace() == NS_FILE ) {
4124                         $types[] = 'upload';
4125                 }
4126
4127                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4128
4129                 return $types;
4130         }
4131
4132         /**
4133          * Returns the raw sort key to be used for categories, with the specified
4134          * prefix.  This will be fed to Language::convertToSortkey() to get a
4135          * binary sortkey that can be used for actual sorting.
4136          *
4137          * @param $prefix string The prefix to be used, specified using
4138          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4139          *   prefix.
4140          * @return string
4141          */
4142         public function getCategorySortkey( $prefix = '' ) {
4143                 $unprefixed = $this->getText();
4144                 if ( $prefix !== '' ) {
4145                         # Separate with a null byte, so the unprefixed part is only used as
4146                         # a tiebreaker when two pages have the exact same prefix -- null
4147                         # sorts before everything else (hopefully).
4148                         return "$prefix\0$unprefixed";
4149                 }
4150                 return $unprefixed;
4151         }
4152 }