includes/specialpage/SpecialPageFactory.php

   1 <?php
   2 /**
   3  * Factory for handling the special page list and generating SpecialPage objects.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  * @defgroup SpecialPage SpecialPage
  23  */
  24
  25 /**
  26  * Factory for handling the special page list and generating SpecialPage objects.
  27  *
  28  * To add a special page in an extension, add to $wgSpecialPages either
  29  * an object instance or an array containing the name and constructor
  30  * parameters. The latter is preferred for performance reasons.
  31  *
  32  * The object instantiated must be either an instance of SpecialPage or a
  33  * sub-class thereof. It must have an execute() method, which sends the HTML
  34  * for the special page to $wgOut. The parent class has an execute() method
  35  * which distributes the call to the historical global functions. Additionally,
  36  * execute() also checks if the user has the necessary access privileges
  37  * and bails out if not.
  38  *
  39  * To add a core special page, use the similar static list in
  40  * SpecialPageFactory::$list. To remove a core static special page at runtime, use
  41  * a SpecialPage_initList hook.
  42  *
  43  * @ingroup SpecialPage
  44  * @since 1.17
  45  */
  46 class SpecialPageFactory {
  47         /**
  48          * List of special page names to the subclass of SpecialPage which handles them.
  49          */
  50         private static $coreList = [
  51                 // Maintenance Reports
  52                 'BrokenRedirects' => 'BrokenRedirectsPage',
  53                 'Deadendpages' => 'DeadendPagesPage',
  54                 'DoubleRedirects' => 'DoubleRedirectsPage',
  55                 'Longpages' => 'LongPagesPage',
  56                 'Ancientpages' => 'AncientPagesPage',
  57                 'Lonelypages' => 'LonelyPagesPage',
  58                 'Fewestrevisions' => 'FewestrevisionsPage',
  59                 'Withoutinterwiki' => 'WithoutInterwikiPage',
  60                 'Protectedpages' => 'SpecialProtectedpages',
  61                 'Protectedtitles' => 'SpecialProtectedtitles',
  62                 'Shortpages' => 'ShortPagesPage',
  63                 'Uncategorizedcategories' => 'UncategorizedCategoriesPage',
  64                 'Uncategorizedimages' => 'UncategorizedImagesPage',
  65                 'Uncategorizedpages' => 'UncategorizedPagesPage',
  66                 'Uncategorizedtemplates' => 'UncategorizedTemplatesPage',
  67                 'Unusedcategories' => 'UnusedCategoriesPage',
  68                 'Unusedimages' => 'UnusedimagesPage',
  69                 'Unusedtemplates' => 'UnusedtemplatesPage',
  70                 'Unwatchedpages' => 'UnwatchedpagesPage',
  71                 'Wantedcategories' => 'WantedCategoriesPage',
  72                 'Wantedfiles' => 'WantedFilesPage',
  73                 'Wantedpages' => 'WantedPagesPage',
  74                 'Wantedtemplates' => 'WantedTemplatesPage',
  75
  76                 // List of pages
  77                 'Allpages' => 'SpecialAllPages',
  78                 'Prefixindex' => 'SpecialPrefixindex',
  79                 'Categories' => 'SpecialCategories',
  80                 'Listredirects' => 'ListredirectsPage',
  81                 'PagesWithProp' => 'SpecialPagesWithProp',
  82                 'TrackingCategories' => 'SpecialTrackingCategories',
  83
  84                 // Authentication
  85                 'Userlogin' => 'SpecialUserLogin',
  86                 'Userlogout' => 'SpecialUserlogoutPreAuthManager',
  87                 'CreateAccount' => 'SpecialCreateAccountPreAuthManager',
  88                 'LinkAccounts' => 'SpecialLinkAccounts',
  89                 'UnlinkAccounts' => 'SpecialUnlinkAccounts',
  90                 'ChangeCredentials' => 'SpecialChangeCredentials',
  91                 'RemoveCredentials' => 'SpecialRemoveCredentials',
  92
  93                 // Users and rights
  94                 'Activeusers' => 'SpecialActiveUsers',
  95                 'Block' => 'SpecialBlock',
  96                 'Unblock' => 'SpecialUnblock',
  97                 'BlockList' => 'SpecialBlockList',
  98                 'ChangePassword' => 'SpecialChangePasswordPreAuthManager',
  99                 'BotPasswords' => 'SpecialBotPasswords',
 100                 'PasswordReset' => 'SpecialPasswordResetPreAuthManager',
 101                 'DeletedContributions' => 'DeletedContributionsPage',
 102                 'Preferences' => 'SpecialPreferences',
 103                 'ResetTokens' => 'SpecialResetTokens',
 104                 'Contributions' => 'SpecialContributions',
 105                 'Listgrouprights' => 'SpecialListGroupRights',
 106                 'Listgrants' => 'SpecialListGrants',
 107                 'Listusers' => 'SpecialListUsers',
 108                 'Listadmins' => 'SpecialListAdmins',
 109                 'Listbots' => 'SpecialListBots',
 110                 'Userrights' => 'UserrightsPage',
 111                 'EditWatchlist' => 'SpecialEditWatchlist',
 112
 113                 // Recent changes and logs
 114                 'Newimages' => 'SpecialNewFiles',
 115                 'Log' => 'SpecialLog',
 116                 'Watchlist' => 'SpecialWatchlist',
 117                 'Newpages' => 'SpecialNewpages',
 118                 'Recentchanges' => 'SpecialRecentChanges',
 119                 'Recentchangeslinked' => 'SpecialRecentChangesLinked',
 120                 'Tags' => 'SpecialTags',
 121
 122                 // Media reports and uploads
 123                 'Listfiles' => 'SpecialListFiles',
 124                 'Filepath' => 'SpecialFilepath',
 125                 'MediaStatistics' => 'MediaStatisticsPage',
 126                 'MIMEsearch' => 'MIMEsearchPage',
 127                 'FileDuplicateSearch' => 'FileDuplicateSearchPage',
 128                 'Upload' => 'SpecialUpload',
 129                 'UploadStash' => 'SpecialUploadStash',
 130                 'ListDuplicatedFiles' => 'ListDuplicatedFilesPage',
 131
 132                 // Data and tools
 133                 'ApiSandbox' => 'SpecialApiSandbox',
 134                 'Statistics' => 'SpecialStatistics',
 135                 'Allmessages' => 'SpecialAllMessages',
 136                 'Version' => 'SpecialVersion',
 137                 'Lockdb' => 'SpecialLockdb',
 138                 'Unlockdb' => 'SpecialUnlockdb',
 139
 140                 // Redirecting special pages
 141                 'LinkSearch' => 'LinkSearchPage',
 142                 'Randompage' => 'RandomPage',
 143                 'RandomInCategory' => 'SpecialRandomInCategory',
 144                 'Randomredirect' => 'SpecialRandomredirect',
 145                 'Randomrootpage' => 'SpecialRandomrootpage',
 146
 147                 // High use pages
 148                 'Mostlinkedcategories' => 'MostlinkedCategoriesPage',
 149                 'Mostimages' => 'MostimagesPage',
 150                 'Mostinterwikis' => 'MostinterwikisPage',
 151                 'Mostlinked' => 'MostlinkedPage',
 152                 'Mostlinkedtemplates' => 'MostlinkedTemplatesPage',
 153                 'Mostcategories' => 'MostcategoriesPage',
 154                 'Mostrevisions' => 'MostrevisionsPage',
 155
 156                 // Page tools
 157                 'ComparePages' => 'SpecialComparePages',
 158                 'Export' => 'SpecialExport',
 159                 'Import' => 'SpecialImport',
 160                 'Undelete' => 'SpecialUndelete',
 161                 'Whatlinkshere' => 'SpecialWhatLinksHere',
 162                 'MergeHistory' => 'SpecialMergeHistory',
 163                 'ExpandTemplates' => 'SpecialExpandTemplates',
 164
 165                 // Other
 166                 'Booksources' => 'SpecialBookSources',
 167
 168                 // Unlisted / redirects
 169                 'ApiHelp' => 'SpecialApiHelp',
 170                 'Blankpage' => 'SpecialBlankpage',
 171                 'Diff' => 'SpecialDiff',
 172                 'EditTags' => 'SpecialEditTags',
 173                 'Emailuser' => 'SpecialEmailUser',
 174                 'Movepage' => 'MovePageForm',
 175                 'Mycontributions' => 'SpecialMycontributions',
 176                 'MyLanguage' => 'SpecialMyLanguage',
 177                 'Mypage' => 'SpecialMypage',
 178                 'Mytalk' => 'SpecialMytalk',
 179                 'Myuploads' => 'SpecialMyuploads',
 180                 'AllMyUploads' => 'SpecialAllMyUploads',
 181                 'PermanentLink' => 'SpecialPermanentLink',
 182                 'Redirect' => 'SpecialRedirect',
 183                 'Revisiondelete' => 'SpecialRevisionDelete',
 184                 'RunJobs' => 'SpecialRunJobs',
 185                 'Specialpages' => 'SpecialSpecialpages',
 186         ];
 187
 188         private static $list;
 189         private static $aliases;
 190         private static $pageObjectCache = [];
 191
 192         /**
 193          * Reset the internal list of special pages. Useful when changing $wgSpecialPages after
 194          * the internal list has already been initialized, e.g. during testing.
 195          */
 196         public static function resetList() {
 197                 self::$list = null;
 198                 self::$aliases = null;
 199                 self::$pageObjectCache = [];
 200         }
 201
 202         /**
 203          * Returns a list of canonical special page names.
 204          * May be used to iterate over all registered special pages.
 205          *
 206          * @return string[]
 207          */
 208         public static function getNames() {
 209                 return array_keys( self::getPageList() );
 210         }
 211
 212         /**
 213          * Get the special page list as an array
 214          *
 215          * @deprecated since 1.24, use getNames() instead.
 216          * @return array
 217          */
 218         public static function getList() {
 219                 wfDeprecated( __FUNCTION__, '1.24' );
 220                 return self::getPageList();
 221         }
 222
 223         /**
 224          * Get the special page list as an array
 225          *
 226          * @return array
 227          */
 228         private static function getPageList() {
 229                 global $wgSpecialPages;
 230                 global $wgDisableInternalSearch, $wgEmailAuthentication;
 231                 global $wgEnableEmail, $wgEnableJavaScriptTest;
 232                 global $wgPageLanguageUseDB, $wgContentHandlerUseDB;
 233                 global $wgDisableAuthManager;
 234
 235                 if ( !is_array( self::$list ) ) {
 236
 237                         self::$list = self::$coreList;
 238
 239                         if ( !$wgDisableInternalSearch ) {
 240                                 self::$list['Search'] = 'SpecialSearch';
 241                         }
 242
 243                         if ( $wgEmailAuthentication ) {
 244                                 self::$list['Confirmemail'] = 'EmailConfirmation';
 245                                 self::$list['Invalidateemail'] = 'EmailInvalidation';
 246                         }
 247
 248                         if ( $wgEnableEmail ) {
 249                                 self::$list['ChangeEmail'] = 'SpecialChangeEmailPreAuthManager';
 250                         }
 251
 252                         if ( $wgEnableJavaScriptTest ) {
 253                                 self::$list['JavaScriptTest'] = 'SpecialJavaScriptTest';
 254                         }
 255
 256                         if ( $wgPageLanguageUseDB ) {
 257                                 self::$list['PageLanguage'] = 'SpecialPageLanguage';
 258                         }
 259                         if ( $wgContentHandlerUseDB ) {
 260                                 self::$list['ChangeContentModel'] = 'SpecialChangeContentModel';
 261                         }
 262
 263                         // horrible hack to allow selection between old and new classes via a feature flag - T110756
 264                         // will be removed once AuthManager is stable
 265                         if ( !$wgDisableAuthManager ) {
 266                                 self::$list = array_map( function ( $class ) {
 267                                         return preg_replace( '/PreAuthManager$/', '', $class );
 268                                 }, self::$list );
 269                                 self::$list['Userlogout'] = 'SpecialUserLogout'; // case matters
 270                         } else {
 271                                 self::$list['Userlogin'] = 'LoginForm';
 272                                 self::$list = array_diff_key( self::$list, array_fill_keys( [
 273                                         'LinkAccounts', 'UnlinkAccounts', 'ChangeCredentials', 'RemoveCredentials',
 274                                 ], true ) );
 275                         }
 276
 277                         // Add extension special pages
 278                         self::$list = array_merge( self::$list, $wgSpecialPages );
 279
 280                         // This hook can be used to disable unwanted core special pages
 281                         // or conditionally register special pages.
 282                         Hooks::run( 'SpecialPage_initList', [ &self::$list ] );
 283
 284                 }
 285
 286                 return self::$list;
 287         }
 288
 289         /**
 290          * Initialise and return the list of special page aliases. Returns an array where
 291          * the key is an alias, and the value is the canonical name of the special page.
 292          * All registered special pages are guaranteed to map to themselves.
 293          * @return array
 294          */
 295         private static function getAliasList() {
 296                 if ( is_null( self::$aliases ) ) {
 297                         global $wgContLang;
 298                         $aliases = $wgContLang->getSpecialPageAliases();
 299                         $pageList = self::getPageList();
 300
 301                         self::$aliases = [];
 302                         $keepAlias = [];
 303
 304                         // Force every canonical name to be an alias for itself.
 305                         foreach ( $pageList as $name => $stuff ) {
 306                                 $caseFoldedAlias = $wgContLang->caseFold( $name );
 307                                 self::$aliases[$caseFoldedAlias] = $name;
 308                                 $keepAlias[$caseFoldedAlias] = 'canonical';
 309                         }
 310
 311                         // Check for $aliases being an array since Language::getSpecialPageAliases can return null
 312                         if ( is_array( $aliases ) ) {
 313                                 foreach ( $aliases as $realName => $aliasList ) {
 314                                         $aliasList = array_values( $aliasList );
 315                                         foreach ( $aliasList as $i => $alias ) {
 316                                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 317
 318                                                 if ( isset( self::$aliases[$caseFoldedAlias] ) &&
 319                                                         $realName === self::$aliases[$caseFoldedAlias]
 320                                                 ) {
 321                                                         // Ignore same-realName conflicts
 322                                                         continue;
 323                                                 }
 324
 325                                                 if ( !isset( $keepAlias[$caseFoldedAlias] ) ) {
 326                                                         self::$aliases[$caseFoldedAlias] = $realName;
 327                                                         if ( !$i ) {
 328                                                                 $keepAlias[$caseFoldedAlias] = 'first';
 329                                                         }
 330                                                 } elseif ( !$i ) {
 331                                                         wfWarn( "First alias '$alias' for $realName conflicts with " .
 332                                                                 "{$keepAlias[$caseFoldedAlias]} alias for " .
 333                                                                 self::$aliases[$caseFoldedAlias]
 334                                                         );
 335                                                 }
 336                                         }
 337                                 }
 338                         }
 339                 }
 340
 341                 return self::$aliases;
 342         }
 343
 344         /**
 345          * Given a special page name with a possible subpage, return an array
 346          * where the first element is the special page name and the second is the
 347          * subpage.
 348          *
 349          * @param string $alias
 350          * @return array Array( String, String|null ), or array( null, null ) if the page is invalid
 351          */
 352         public static function resolveAlias( $alias ) {
 353                 global $wgContLang;
 354                 $bits = explode( '/', $alias, 2 );
 355
 356                 $caseFoldedAlias = $wgContLang->caseFold( $bits[0] );
 357                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 358                 $aliases = self::getAliasList();
 359                 if ( isset( $aliases[$caseFoldedAlias] ) ) {
 360                         $name = $aliases[$caseFoldedAlias];
 361                 } else {
 362                         return [ null, null ];
 363                 }
 364
 365                 if ( !isset( $bits[1] ) ) { // bug 2087
 366                         $par = null;
 367                 } else {
 368                         $par = $bits[1];
 369                 }
 370
 371                 return [ $name, $par ];
 372         }
 373
 374         /**
 375          * Check if a given name exist as a special page or as a special page alias
 376          *
 377          * @param string $name Name of a special page
 378          * @return bool True if a special page exists with this name
 379          */
 380         public static function exists( $name ) {
 381                 list( $title, /*...*/ ) = self::resolveAlias( $name );
 382
 383                 $specialPageList = self::getPageList();
 384                 return isset( $specialPageList[$title] );
 385         }
 386
 387         /**
 388          * Find the object with a given name and return it (or NULL)
 389          *
 390          * @param string $name Special page name, may be localised and/or an alias
 391          * @return SpecialPage|null SpecialPage object or null if the page doesn't exist
 392          */
 393         public static function getPage( $name ) {
 394                 list( $realName, /*...*/ ) = self::resolveAlias( $name );
 395
 396                 if ( isset( self::$pageObjectCache[$realName] ) ) {
 397                         return self::$pageObjectCache[$realName];
 398                 }
 399
 400                 $specialPageList = self::getPageList();
 401
 402                 if ( isset( $specialPageList[$realName] ) ) {
 403                         $rec = $specialPageList[$realName];
 404
 405                         if ( is_callable( $rec ) ) {
 406                                 // Use callback to instantiate the special page
 407                                 $page = call_user_func( $rec );
 408                         } elseif ( is_string( $rec ) ) {
 409                                 $className = $rec;
 410                                 $page = new $className;
 411                         } elseif ( is_array( $rec ) ) {
 412                                 $className = array_shift( $rec );
 413                                 // @deprecated, officially since 1.18, unofficially since forever
 414                                 wfDeprecated( "Array syntax for \$wgSpecialPages is deprecated ($className), " .
 415                                         "define a subclass of SpecialPage instead.", '1.18' );
 416                                 $page = ObjectFactory::getObjectFromSpec( [
 417                                         'class' => $className,
 418                                         'args' => $rec,
 419                                         'closure_expansion' => false,
 420                                 ] );
 421                         } elseif ( $rec instanceof SpecialPage ) {
 422                                 $page = $rec; // XXX: we should deep clone here
 423                         } else {
 424                                 $page = null;
 425                         }
 426
 427                         self::$pageObjectCache[$realName] = $page;
 428                         if ( $page instanceof SpecialPage ) {
 429                                 return $page;
 430                         } else {
 431                                 // It's not a classname, nor a callback, nor a legacy constructor array,
 432                                 // nor a special page object. Give up.
 433                                 wfLogWarning( "Cannot instantiate special page $realName: bad spec!" );
 434                                 return null;
 435                         }
 436
 437                 } else {
 438                         return null;
 439                 }
 440         }
 441
 442         /**
 443          * Return categorised listable special pages which are available
 444          * for the current user, and everyone.
 445          *
 446          * @param User $user User object to check permissions, $wgUser will be used
 447          *        if not provided
 448          * @return array ( string => Specialpage )
 449          */
 450         public static function getUsablePages( User $user = null ) {
 451                 $pages = [];
 452                 if ( $user === null ) {
 453                         global $wgUser;
 454                         $user = $wgUser;
 455                 }
 456                 foreach ( self::getPageList() as $name => $rec ) {
 457                         $page = self::getPage( $name );
 458                         if ( $page ) { // not null
 459                                 $page->setContext( RequestContext::getMain() );
 460                                 if ( $page->isListed()
 461                                         && ( !$page->isRestricted() || $page->userCanExecute( $user ) )
 462                                 ) {
 463                                         $pages[$name] = $page;
 464                                 }
 465                         }
 466                 }
 467
 468                 return $pages;
 469         }
 470
 471         /**
 472          * Return categorised listable special pages for all users
 473          *
 474          * @return array ( string => Specialpage )
 475          */
 476         public static function getRegularPages() {
 477                 $pages = [];
 478                 foreach ( self::getPageList() as $name => $rec ) {
 479                         $page = self::getPage( $name );
 480                         if ( $page->isListed() && !$page->isRestricted() ) {
 481                                 $pages[$name] = $page;
 482                         }
 483                 }
 484
 485                 return $pages;
 486         }
 487
 488         /**
 489          * Return categorised listable special pages which are available
 490          * for the current user, but not for everyone
 491          *
 492          * @param User|null $user User object to use or null for $wgUser
 493          * @return array ( string => Specialpage )
 494          */
 495         public static function getRestrictedPages( User $user = null ) {
 496                 $pages = [];
 497                 if ( $user === null ) {
 498                         global $wgUser;
 499                         $user = $wgUser;
 500                 }
 501                 foreach ( self::getPageList() as $name => $rec ) {
 502                         $page = self::getPage( $name );
 503                         if (
 504                                 $page->isListed()
 505                                 && $page->isRestricted()
 506                                 && $page->userCanExecute( $user )
 507                         ) {
 508                                 $pages[$name] = $page;
 509                         }
 510                 }
 511
 512                 return $pages;
 513         }
 514
 515         /**
 516          * Execute a special page path.
 517          * The path may contain parameters, e.g. Special:Name/Params
 518          * Extracts the special page name and call the execute method, passing the parameters
 519          *
 520          * Returns a title object if the page is redirected, false if there was no such special
 521          * page, and true if it was successful.
 522          *
 523          * @param Title $title
 524          * @param IContextSource $context
 525          * @param bool $including Bool output is being captured for use in {{special:whatever}}
 526          *
 527          * @return bool
 528          */
 529         public static function executePath( Title &$title, IContextSource &$context, $including = false ) {
 530                 // @todo FIXME: Redirects broken due to this call
 531                 $bits = explode( '/', $title->getDBkey(), 2 );
 532                 $name = $bits[0];
 533                 if ( !isset( $bits[1] ) ) { // bug 2087
 534                         $par = null;
 535                 } else {
 536                         $par = $bits[1];
 537                 }
 538
 539                 $page = self::getPage( $name );
 540                 if ( !$page ) {
 541                         $context->getOutput()->setArticleRelated( false );
 542                         $context->getOutput()->setRobotPolicy( 'noindex,nofollow' );
 543
 544                         global $wgSend404Code;
 545                         if ( $wgSend404Code ) {
 546                                 $context->getOutput()->setStatusCode( 404 );
 547                         }
 548
 549                         $context->getOutput()->showErrorPage( 'nosuchspecialpage', 'nospecialpagetext' );
 550
 551                         return false;
 552                 }
 553
 554                 if ( !$including ) {
 555                         // Narrow DB query expectations for this HTTP request
 556                         $trxLimits = $context->getConfig()->get( 'TrxProfilerLimits' );
 557                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 558                         if ( $context->getRequest()->wasPosted() && !$page->doesWrites() ) {
 559                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 560                                 $context->getRequest()->markAsSafeRequest();
 561                         }
 562                 }
 563
 564                 // Page exists, set the context
 565                 $page->setContext( $context );
 566
 567                 if ( !$including ) {
 568                         // Redirect to canonical alias for GET commands
 569                         // Not for POST, we'd lose the post data, so it's best to just distribute
 570                         // the request. Such POST requests are possible for old extensions that
 571                         // generate self-links without being aware that their default name has
 572                         // changed.
 573                         if ( $name != $page->getLocalName() && !$context->getRequest()->wasPosted() ) {
 574                                 $query = $context->getRequest()->getQueryValues();
 575                                 unset( $query['title'] );
 576                                 $title = $page->getPageTitle( $par );
 577                                 $url = $title->getFullURL( $query );
 578                                 $context->getOutput()->redirect( $url );
 579
 580                                 return $title;
 581                         } else {
 582                                 $context->setTitle( $page->getPageTitle( $par ) );
 583                         }
 584                 } elseif ( !$page->isIncludable() ) {
 585                         return false;
 586                 }
 587
 588                 $page->including( $including );
 589
 590                 // Execute special page
 591                 $page->run( $par );
 592
 593                 return true;
 594         }
 595
 596         /**
 597          * Just like executePath() but will override global variables and execute
 598          * the page in "inclusion" mode. Returns true if the execution was
 599          * successful or false if there was no such special page, or a title object
 600          * if it was a redirect.
 601          *
 602          * Also saves the current $wgTitle, $wgOut, $wgRequest, $wgUser and $wgLang
 603          * variables so that the special page will get the context it'd expect on a
 604          * normal request, and then restores them to their previous values after.
 605          *
 606          * @param Title $title
 607          * @param IContextSource $context
 608          * @return string HTML fragment
 609          */
 610         public static function capturePath( Title $title, IContextSource $context ) {
 611                 global $wgTitle, $wgOut, $wgRequest, $wgUser, $wgLang;
 612                 $main = RequestContext::getMain();
 613
 614                 // Save current globals and main context
 615                 $glob = [
 616                         'title' => $wgTitle,
 617                         'output' => $wgOut,
 618                         'request' => $wgRequest,
 619                         'user' => $wgUser,
 620                         'language' => $wgLang,
 621                 ];
 622                 $ctx = [
 623                         'title' => $main->getTitle(),
 624                         'output' => $main->getOutput(),
 625                         'request' => $main->getRequest(),
 626                         'user' => $main->getUser(),
 627                         'language' => $main->getLanguage(),
 628                 ];
 629
 630                 // Override
 631                 $wgTitle = $title;
 632                 $wgOut = $context->getOutput();
 633                 $wgRequest = $context->getRequest();
 634                 $wgUser = $context->getUser();
 635                 $wgLang = $context->getLanguage();
 636                 $main->setTitle( $title );
 637                 $main->setOutput( $context->getOutput() );
 638                 $main->setRequest( $context->getRequest() );
 639                 $main->setUser( $context->getUser() );
 640                 $main->setLanguage( $context->getLanguage() );
 641
 642                 // The useful part
 643                 $ret = self::executePath( $title, $context, true );
 644
 645                 // Restore old globals and context
 646                 $wgTitle = $glob['title'];
 647                 $wgOut = $glob['output'];
 648                 $wgRequest = $glob['request'];
 649                 $wgUser = $glob['user'];
 650                 $wgLang = $glob['language'];
 651                 $main->setTitle( $ctx['title'] );
 652                 $main->setOutput( $ctx['output'] );
 653                 $main->setRequest( $ctx['request'] );
 654                 $main->setUser( $ctx['user'] );
 655                 $main->setLanguage( $ctx['language'] );
 656
 657                 return $ret;
 658         }
 659
 660         /**
 661          * Get the local name for a specified canonical name
 662          *
 663          * @param string $name
 664          * @param string|bool $subpage
 665          * @return string
 666          */
 667         public static function getLocalNameFor( $name, $subpage = false ) {
 668                 global $wgContLang;
 669                 $aliases = $wgContLang->getSpecialPageAliases();
 670                 $aliasList = self::getAliasList();
 671
 672                 // Find the first alias that maps back to $name
 673                 if ( isset( $aliases[$name] ) ) {
 674                         $found = false;
 675                         foreach ( $aliases[$name] as $alias ) {
 676                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 677                                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 678                                 if ( isset( $aliasList[$caseFoldedAlias] ) &&
 679                                         $aliasList[$caseFoldedAlias] === $name
 680                                 ) {
 681                                         $name = $alias;
 682                                         $found = true;
 683                                         break;
 684                                 }
 685                         }
 686                         if ( !$found ) {
 687                                 wfWarn( "Did not find a usable alias for special page '$name'. " .
 688                                         "It seems all defined aliases conflict?" );
 689                         }
 690                 } else {
 691                         // Check if someone misspelled the correct casing
 692                         if ( is_array( $aliases ) ) {
 693                                 foreach ( $aliases as $n => $values ) {
 694                                         if ( strcasecmp( $name, $n ) === 0 ) {
 695                                                 wfWarn( "Found alias defined for $n when searching for " .
 696                                                         "special page aliases for $name. Case mismatch?" );
 697                                                 return self::getLocalNameFor( $n, $subpage );
 698                                         }
 699                                 }
 700                         }
 701
 702                         wfWarn( "Did not find alias for special page '$name'. " .
 703                                 "Perhaps no aliases are defined for it?" );
 704                 }
 705
 706                 if ( $subpage !== false && !is_null( $subpage ) ) {
 707                         $name = "$name/$subpage";
 708                 }
 709
 710                 return $wgContLang->ucfirst( $name );
 711         }
 712
 713         /**
 714          * Get a title for a given alias
 715          *
 716          * @param string $alias
 717          * @return Title|null Title or null if there is no such alias
 718          */
 719         public static function getTitleForAlias( $alias ) {
 720                 list( $name, $subpage ) = self::resolveAlias( $alias );
 721                 if ( $name != null ) {
 722                         return SpecialPage::getTitleFor( $name, $subpage );
 723                 } else {
 724                         return null;
 725                 }
 726         }
 727 }