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 namespace MediaWiki\Special;
  26
  27 use Config;
  28 use Hooks;
  29 use IContextSource;
  30 use Language;
  31 use MediaWiki\Linker\LinkRenderer;
  32 use Profiler;
  33 use RequestContext;
  34 use SpecialPage;
  35 use Title;
  36 use User;
  37 use Wikimedia\ObjectFactory;
  38
  39 /**
  40  * Factory for handling the special page list and generating SpecialPage objects.
  41  *
  42  * To add a special page in an extension, add to $wgSpecialPages either
  43  * an object instance or an array containing the name and constructor
  44  * parameters. The latter is preferred for performance reasons.
  45  *
  46  * The object instantiated must be either an instance of SpecialPage or a
  47  * sub-class thereof. It must have an execute() method, which sends the HTML
  48  * for the special page to $wgOut. The parent class has an execute() method
  49  * which distributes the call to the historical global functions. Additionally,
  50  * execute() also checks if the user has the necessary access privileges
  51  * and bails out if not.
  52  *
  53  * To add a core special page, use the similar static list in
  54  * SpecialPageFactory::$list. To remove a core static special page at runtime, use
  55  * a SpecialPage_initList hook.
  56  *
  57  * @note There are two classes called SpecialPageFactory.  You should use this first one, in
  58  * namespace MediaWiki\Special, which is a service.  \SpecialPageFactory is a deprecated collection
  59  * of static methods that forwards to the global service.
  60  *
  61  * @ingroup SpecialPage
  62  * @since 1.17
  63  */
  64 class SpecialPageFactory {
  65         /**
  66          * List of special page names to the subclass of SpecialPage which handles them.
  67          * @todo Make this a const when we drop HHVM support (T192166).  It can still be private in PHP
  68          * 7.1.
  69          */
  70         private static $coreList = [
  71                 // Maintenance Reports
  72                 'BrokenRedirects' => \BrokenRedirectsPage::class,
  73                 'Deadendpages' => \DeadendPagesPage::class,
  74                 'DoubleRedirects' => \DoubleRedirectsPage::class,
  75                 'Longpages' => \LongPagesPage::class,
  76                 'Ancientpages' => \AncientPagesPage::class,
  77                 'Lonelypages' => \LonelyPagesPage::class,
  78                 'Fewestrevisions' => \FewestrevisionsPage::class,
  79                 'Withoutinterwiki' => \WithoutInterwikiPage::class,
  80                 'Protectedpages' => \SpecialProtectedpages::class,
  81                 'Protectedtitles' => \SpecialProtectedtitles::class,
  82                 'Shortpages' => \ShortPagesPage::class,
  83                 'Uncategorizedcategories' => \UncategorizedCategoriesPage::class,
  84                 'Uncategorizedimages' => \UncategorizedImagesPage::class,
  85                 'Uncategorizedpages' => \UncategorizedPagesPage::class,
  86                 'Uncategorizedtemplates' => \UncategorizedTemplatesPage::class,
  87                 'Unusedcategories' => \UnusedCategoriesPage::class,
  88                 'Unusedimages' => \UnusedimagesPage::class,
  89                 'Unusedtemplates' => \UnusedtemplatesPage::class,
  90                 'Unwatchedpages' => \UnwatchedpagesPage::class,
  91                 'Wantedcategories' => \WantedCategoriesPage::class,
  92                 'Wantedfiles' => \WantedFilesPage::class,
  93                 'Wantedpages' => \WantedPagesPage::class,
  94                 'Wantedtemplates' => \WantedTemplatesPage::class,
  95
  96                 // List of pages
  97                 'Allpages' => \SpecialAllPages::class,
  98                 'Prefixindex' => \SpecialPrefixindex::class,
  99                 'Categories' => \SpecialCategories::class,
 100                 'Listredirects' => \ListredirectsPage::class,
 101                 'PagesWithProp' => \SpecialPagesWithProp::class,
 102                 'TrackingCategories' => \SpecialTrackingCategories::class,
 103
 104                 // Authentication
 105                 'Userlogin' => \SpecialUserLogin::class,
 106                 'Userlogout' => \SpecialUserLogout::class,
 107                 'CreateAccount' => \SpecialCreateAccount::class,
 108                 'LinkAccounts' => \SpecialLinkAccounts::class,
 109                 'UnlinkAccounts' => \SpecialUnlinkAccounts::class,
 110                 'ChangeCredentials' => \SpecialChangeCredentials::class,
 111                 'RemoveCredentials' => \SpecialRemoveCredentials::class,
 112
 113                 // Users and rights
 114                 'Activeusers' => \SpecialActiveUsers::class,
 115                 'Block' => \SpecialBlock::class,
 116                 'Unblock' => \SpecialUnblock::class,
 117                 'BlockList' => \SpecialBlockList::class,
 118                 'AutoblockList' => \SpecialAutoblockList::class,
 119                 'ChangePassword' => \SpecialChangePassword::class,
 120                 'BotPasswords' => \SpecialBotPasswords::class,
 121                 'PasswordReset' => \SpecialPasswordReset::class,
 122                 'DeletedContributions' => \DeletedContributionsPage::class,
 123                 'Preferences' => \SpecialPreferences::class,
 124                 'ResetTokens' => \SpecialResetTokens::class,
 125                 'Contributions' => \SpecialContributions::class,
 126                 'Listgrouprights' => \SpecialListGroupRights::class,
 127                 'Listgrants' => \SpecialListGrants::class,
 128                 'Listusers' => \SpecialListUsers::class,
 129                 'Listadmins' => \SpecialListAdmins::class,
 130                 'Listbots' => \SpecialListBots::class,
 131                 'Userrights' => \UserrightsPage::class,
 132                 'EditWatchlist' => \SpecialEditWatchlist::class,
 133                 'PasswordPolicies' => \SpecialPasswordPolicies::class,
 134
 135                 // Recent changes and logs
 136                 'Newimages' => \SpecialNewFiles::class,
 137                 'Log' => \SpecialLog::class,
 138                 'Watchlist' => \SpecialWatchlist::class,
 139                 'Newpages' => \SpecialNewpages::class,
 140                 'Recentchanges' => \SpecialRecentChanges::class,
 141                 'Recentchangeslinked' => \SpecialRecentChangesLinked::class,
 142                 'Tags' => \SpecialTags::class,
 143
 144                 // Media reports and uploads
 145                 'Listfiles' => \SpecialListFiles::class,
 146                 'Filepath' => \SpecialFilepath::class,
 147                 'MediaStatistics' => \MediaStatisticsPage::class,
 148                 'MIMEsearch' => \MIMEsearchPage::class,
 149                 'FileDuplicateSearch' => \FileDuplicateSearchPage::class,
 150                 'Upload' => \SpecialUpload::class,
 151                 'UploadStash' => \SpecialUploadStash::class,
 152                 'ListDuplicatedFiles' => \ListDuplicatedFilesPage::class,
 153
 154                 // Data and tools
 155                 'ApiSandbox' => \SpecialApiSandbox::class,
 156                 'Statistics' => \SpecialStatistics::class,
 157                 'Allmessages' => \SpecialAllMessages::class,
 158                 'Version' => \SpecialVersion::class,
 159                 'Lockdb' => \SpecialLockdb::class,
 160                 'Unlockdb' => \SpecialUnlockdb::class,
 161
 162                 // Redirecting special pages
 163                 'LinkSearch' => \LinkSearchPage::class,
 164                 'Randompage' => \RandomPage::class,
 165                 'RandomInCategory' => \SpecialRandomInCategory::class,
 166                 'Randomredirect' => \SpecialRandomredirect::class,
 167                 'Randomrootpage' => \SpecialRandomrootpage::class,
 168                 'GoToInterwiki' => \SpecialGoToInterwiki::class,
 169
 170                 // High use pages
 171                 'Mostlinkedcategories' => \MostlinkedCategoriesPage::class,
 172                 'Mostimages' => \MostimagesPage::class,
 173                 'Mostinterwikis' => \MostinterwikisPage::class,
 174                 'Mostlinked' => \MostlinkedPage::class,
 175                 'Mostlinkedtemplates' => \MostlinkedTemplatesPage::class,
 176                 'Mostcategories' => \MostcategoriesPage::class,
 177                 'Mostrevisions' => \MostrevisionsPage::class,
 178
 179                 // Page tools
 180                 'ComparePages' => \SpecialComparePages::class,
 181                 'Export' => \SpecialExport::class,
 182                 'Import' => \SpecialImport::class,
 183                 'Undelete' => \SpecialUndelete::class,
 184                 'Whatlinkshere' => \SpecialWhatLinksHere::class,
 185                 'MergeHistory' => \SpecialMergeHistory::class,
 186                 'ExpandTemplates' => \SpecialExpandTemplates::class,
 187
 188                 // Other
 189                 'Booksources' => \SpecialBookSources::class,
 190
 191                 // Unlisted / redirects
 192                 'ApiHelp' => \SpecialApiHelp::class,
 193                 'Blankpage' => \SpecialBlankpage::class,
 194                 'Diff' => \SpecialDiff::class,
 195                 'EditTags' => \SpecialEditTags::class,
 196                 'Emailuser' => \SpecialEmailUser::class,
 197                 'Movepage' => \MovePageForm::class,
 198                 'Mycontributions' => \SpecialMycontributions::class,
 199                 'MyLanguage' => \SpecialMyLanguage::class,
 200                 'Mypage' => \SpecialMypage::class,
 201                 'Mytalk' => \SpecialMytalk::class,
 202                 'Myuploads' => \SpecialMyuploads::class,
 203                 'AllMyUploads' => \SpecialAllMyUploads::class,
 204                 'PermanentLink' => \SpecialPermanentLink::class,
 205                 'Redirect' => \SpecialRedirect::class,
 206                 'Revisiondelete' => \SpecialRevisionDelete::class,
 207                 'RunJobs' => \SpecialRunJobs::class,
 208                 'Specialpages' => \SpecialSpecialpages::class,
 209                 'PageData' => \SpecialPageData::class,
 210         ];
 211
 212         /** @var array Special page name => class name */
 213         private $list;
 214
 215         /** @var array */
 216         private $aliases;
 217
 218         /** @var Config */
 219         private $config;
 220
 221         /** @var Language */
 222         private $contLang;
 223
 224         /**
 225          * @param Config $config
 226          * @param Language $contLang
 227          */
 228         public function __construct( Config $config, Language $contLang ) {
 229                 $this->config = $config;
 230                 $this->contLang = $contLang;
 231         }
 232
 233         /**
 234          * Returns a list of canonical special page names.
 235          * May be used to iterate over all registered special pages.
 236          *
 237          * @return string[]
 238          */
 239         public function getNames() : array {
 240                 return array_keys( $this->getPageList() );
 241         }
 242
 243         /**
 244          * Get the special page list as an array
 245          *
 246          * @return array
 247          */
 248         private function getPageList() : array {
 249                 if ( !is_array( $this->list ) ) {
 250                         $this->list = self::$coreList;
 251
 252                         if ( !$this->config->get( 'DisableInternalSearch' ) ) {
 253                                 $this->list['Search'] = \SpecialSearch::class;
 254                         }
 255
 256                         if ( $this->config->get( 'EmailAuthentication' ) ) {
 257                                 $this->list['Confirmemail'] = \EmailConfirmation::class;
 258                                 $this->list['Invalidateemail'] = \EmailInvalidation::class;
 259                         }
 260
 261                         if ( $this->config->get( 'EnableEmail' ) ) {
 262                                 $this->list['ChangeEmail'] = \SpecialChangeEmail::class;
 263                         }
 264
 265                         if ( $this->config->get( 'EnableJavaScriptTest' ) ) {
 266                                 $this->list['JavaScriptTest'] = \SpecialJavaScriptTest::class;
 267                         }
 268
 269                         if ( $this->config->get( 'PageLanguageUseDB' ) ) {
 270                                 $this->list['PageLanguage'] = \SpecialPageLanguage::class;
 271                         }
 272                         if ( $this->config->get( 'ContentHandlerUseDB' ) ) {
 273                                 $this->list['ChangeContentModel'] = \SpecialChangeContentModel::class;
 274                         }
 275
 276                         // Add extension special pages
 277                         $this->list = array_merge( $this->list, $this->config->get( 'SpecialPages' ) );
 278
 279                         // This hook can be used to disable unwanted core special pages
 280                         // or conditionally register special pages.
 281                         Hooks::run( 'SpecialPage_initList', [ &$this->list ] );
 282
 283                 }
 284
 285                 return $this->list;
 286         }
 287
 288         /**
 289          * Initialise and return the list of special page aliases. Returns an array where
 290          * the key is an alias, and the value is the canonical name of the special page.
 291          * All registered special pages are guaranteed to map to themselves.
 292          * @return array
 293          */
 294         private function getAliasList() : array {
 295                 if ( is_null( $this->aliases ) ) {
 296                         $aliases = $this->contLang->getSpecialPageAliases();
 297                         $pageList = $this->getPageList();
 298
 299                         $this->aliases = [];
 300                         $keepAlias = [];
 301
 302                         // Force every canonical name to be an alias for itself.
 303                         foreach ( $pageList as $name => $stuff ) {
 304                                 $caseFoldedAlias = $this->contLang->caseFold( $name );
 305                                 $this->aliases[$caseFoldedAlias] = $name;
 306                                 $keepAlias[$caseFoldedAlias] = 'canonical';
 307                         }
 308
 309                         // Check for $aliases being an array since Language::getSpecialPageAliases can return null
 310                         if ( is_array( $aliases ) ) {
 311                                 foreach ( $aliases as $realName => $aliasList ) {
 312                                         $aliasList = array_values( $aliasList );
 313                                         foreach ( $aliasList as $i => $alias ) {
 314                                                 $caseFoldedAlias = $this->contLang->caseFold( $alias );
 315
 316                                                 if ( isset( $this->aliases[$caseFoldedAlias] ) &&
 317                                                         $realName === $this->aliases[$caseFoldedAlias]
 318                                                 ) {
 319                                                         // Ignore same-realName conflicts
 320                                                         continue;
 321                                                 }
 322
 323                                                 if ( !isset( $keepAlias[$caseFoldedAlias] ) ) {
 324                                                         $this->aliases[$caseFoldedAlias] = $realName;
 325                                                         if ( !$i ) {
 326                                                                 $keepAlias[$caseFoldedAlias] = 'first';
 327                                                         }
 328                                                 } elseif ( !$i ) {
 329                                                         wfWarn( "First alias '$alias' for $realName conflicts with " .
 330                                                                 "{$keepAlias[$caseFoldedAlias]} alias for " .
 331                                                                 $this->aliases[$caseFoldedAlias]
 332                                                         );
 333                                                 }
 334                                         }
 335                                 }
 336                         }
 337                 }
 338
 339                 return $this->aliases;
 340         }
 341
 342         /**
 343          * Given a special page name with a possible subpage, return an array
 344          * where the first element is the special page name and the second is the
 345          * subpage.
 346          *
 347          * @param string $alias
 348          * @return array Array( String, String|null ), or array( null, null ) if the page is invalid
 349          */
 350         public function resolveAlias( $alias ) {
 351                 $bits = explode( '/', $alias, 2 );
 352
 353                 $caseFoldedAlias = $this->contLang->caseFold( $bits[0] );
 354                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 355                 $aliases = $this->getAliasList();
 356                 if ( isset( $aliases[$caseFoldedAlias] ) ) {
 357                         $name = $aliases[$caseFoldedAlias];
 358                 } else {
 359                         return [ null, null ];
 360                 }
 361
 362                 if ( !isset( $bits[1] ) ) { // T4087
 363                         $par = null;
 364                 } else {
 365                         $par = $bits[1];
 366                 }
 367
 368                 return [ $name, $par ];
 369         }
 370
 371         /**
 372          * Check if a given name exist as a special page or as a special page alias
 373          *
 374          * @param string $name Name of a special page
 375          * @return bool True if a special page exists with this name
 376          */
 377         public function exists( $name ) {
 378                 list( $title, /*...*/ ) = $this->resolveAlias( $name );
 379
 380                 $specialPageList = $this->getPageList();
 381                 return isset( $specialPageList[$title] );
 382         }
 383
 384         /**
 385          * Find the object with a given name and return it (or NULL)
 386          *
 387          * @param string $name Special page name, may be localised and/or an alias
 388          * @return SpecialPage|null SpecialPage object or null if the page doesn't exist
 389          */
 390         public function getPage( $name ) {
 391                 list( $realName, /*...*/ ) = $this->resolveAlias( $name );
 392
 393                 $specialPageList = $this->getPageList();
 394
 395                 if ( isset( $specialPageList[$realName] ) ) {
 396                         $rec = $specialPageList[$realName];
 397
 398                         if ( is_callable( $rec ) ) {
 399                                 // Use callback to instantiate the special page
 400                                 $page = $rec();
 401                         } elseif ( is_string( $rec ) ) {
 402                                 $className = $rec;
 403                                 $page = new $className;
 404                         } elseif ( is_array( $rec ) ) {
 405                                 $className = array_shift( $rec );
 406                                 // @deprecated, officially since 1.18, unofficially since forever
 407                                 wfDeprecated( "Array syntax for \$wgSpecialPages is deprecated ($className), " .
 408                                         "define a subclass of SpecialPage instead.", '1.18' );
 409                                 $page = ObjectFactory::getObjectFromSpec( [
 410                                         'class' => $className,
 411                                         'args' => $rec,
 412                                         'closure_expansion' => false,
 413                                 ] );
 414                         } elseif ( $rec instanceof SpecialPage ) {
 415                                 $page = $rec; // XXX: we should deep clone here
 416                         } else {
 417                                 $page = null;
 418                         }
 419
 420                         if ( $page instanceof SpecialPage ) {
 421                                 return $page;
 422                         }
 423
 424                         // It's not a classname, nor a callback, nor a legacy constructor array,
 425                         // nor a special page object. Give up.
 426                         wfLogWarning( "Cannot instantiate special page $realName: bad spec!" );
 427                 }
 428
 429                 return null;
 430         }
 431
 432         /**
 433          * Return categorised listable special pages which are available
 434          * for the current user, and everyone.
 435          *
 436          * @param User $user User object to check permissions
 437          *  provided
 438          * @return array ( string => Specialpage )
 439          */
 440         public function getUsablePages( User $user ) : array {
 441                 $pages = [];
 442                 foreach ( $this->getPageList() as $name => $rec ) {
 443                         $page = $this->getPage( $name );
 444                         if ( $page ) { // not null
 445                                 $page->setContext( RequestContext::getMain() );
 446                                 if ( $page->isListed()
 447                                         && ( !$page->isRestricted() || $page->userCanExecute( $user ) )
 448                                 ) {
 449                                         $pages[$name] = $page;
 450                                 }
 451                         }
 452                 }
 453
 454                 return $pages;
 455         }
 456
 457         /**
 458          * Return categorised listable special pages for all users
 459          *
 460          * @return array ( string => Specialpage )
 461          */
 462         public function getRegularPages() : array {
 463                 $pages = [];
 464                 foreach ( $this->getPageList() as $name => $rec ) {
 465                         $page = $this->getPage( $name );
 466                         if ( $page && $page->isListed() && !$page->isRestricted() ) {
 467                                 $pages[$name] = $page;
 468                         }
 469                 }
 470
 471                 return $pages;
 472         }
 473
 474         /**
 475          * Return categorised listable special pages which are available
 476          * for the current user, but not for everyone
 477          *
 478          * @param User $user User object to use
 479          * @return array ( string => Specialpage )
 480          */
 481         public function getRestrictedPages( User $user ) : array {
 482                 $pages = [];
 483                 foreach ( $this->getPageList() as $name => $rec ) {
 484                         $page = $this->getPage( $name );
 485                         if ( $page
 486                                 && $page->isListed()
 487                                 && $page->isRestricted()
 488                                 && $page->userCanExecute( $user )
 489                         ) {
 490                                 $pages[$name] = $page;
 491                         }
 492                 }
 493
 494                 return $pages;
 495         }
 496
 497         /**
 498          * Execute a special page path.
 499          * The path may contain parameters, e.g. Special:Name/Params
 500          * Extracts the special page name and call the execute method, passing the parameters
 501          *
 502          * Returns a title object if the page is redirected, false if there was no such special
 503          * page, and true if it was successful.
 504          *
 505          * @param Title &$title
 506          * @param IContextSource &$context
 507          * @param bool $including Bool output is being captured for use in {{special:whatever}}
 508          * @param LinkRenderer|null $linkRenderer (since 1.28)
 509          *
 510          * @return bool|Title
 511          */
 512         public function executePath( Title &$title, IContextSource &$context, $including = false,
 513                 LinkRenderer $linkRenderer = null
 514         ) {
 515                 // @todo FIXME: Redirects broken due to this call
 516                 $bits = explode( '/', $title->getDBkey(), 2 );
 517                 $name = $bits[0];
 518                 if ( !isset( $bits[1] ) ) { // T4087
 519                         $par = null;
 520                 } else {
 521                         $par = $bits[1];
 522                 }
 523
 524                 $page = $this->getPage( $name );
 525                 if ( !$page ) {
 526                         $context->getOutput()->setArticleRelated( false );
 527                         $context->getOutput()->setRobotPolicy( 'noindex,nofollow' );
 528
 529                         global $wgSend404Code;
 530                         if ( $wgSend404Code ) {
 531                                 $context->getOutput()->setStatusCode( 404 );
 532                         }
 533
 534                         $context->getOutput()->showErrorPage( 'nosuchspecialpage', 'nospecialpagetext' );
 535
 536                         return false;
 537                 }
 538
 539                 if ( !$including ) {
 540                         // Narrow DB query expectations for this HTTP request
 541                         $trxLimits = $context->getConfig()->get( 'TrxProfilerLimits' );
 542                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 543                         if ( $context->getRequest()->wasPosted() && !$page->doesWrites() ) {
 544                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 545                                 $context->getRequest()->markAsSafeRequest();
 546                         }
 547                 }
 548
 549                 // Page exists, set the context
 550                 $page->setContext( $context );
 551
 552                 if ( !$including ) {
 553                         // Redirect to canonical alias for GET commands
 554                         // Not for POST, we'd lose the post data, so it's best to just distribute
 555                         // the request. Such POST requests are possible for old extensions that
 556                         // generate self-links without being aware that their default name has
 557                         // changed.
 558                         if ( $name != $page->getLocalName() && !$context->getRequest()->wasPosted() ) {
 559                                 $query = $context->getRequest()->getQueryValues();
 560                                 unset( $query['title'] );
 561                                 $title = $page->getPageTitle( $par );
 562                                 $url = $title->getFullURL( $query );
 563                                 $context->getOutput()->redirect( $url );
 564
 565                                 return $title;
 566                         }
 567
 568                         $context->setTitle( $page->getPageTitle( $par ) );
 569                 } elseif ( !$page->isIncludable() ) {
 570                         return false;
 571                 }
 572
 573                 $page->including( $including );
 574                 if ( $linkRenderer ) {
 575                         $page->setLinkRenderer( $linkRenderer );
 576                 }
 577
 578                 // Execute special page
 579                 $page->run( $par );
 580
 581                 return true;
 582         }
 583
 584         /**
 585          * Just like executePath() but will override global variables and execute
 586          * the page in "inclusion" mode. Returns true if the execution was
 587          * successful or false if there was no such special page, or a title object
 588          * if it was a redirect.
 589          *
 590          * Also saves the current $wgTitle, $wgOut, $wgRequest, $wgUser and $wgLang
 591          * variables so that the special page will get the context it'd expect on a
 592          * normal request, and then restores them to their previous values after.
 593          *
 594          * @param Title $title
 595          * @param IContextSource $context
 596          * @param LinkRenderer|null $linkRenderer (since 1.28)
 597          * @return string HTML fragment
 598          */
 599         public function capturePath(
 600                 Title $title, IContextSource $context, LinkRenderer $linkRenderer = null
 601         ) {
 602                 global $wgTitle, $wgOut, $wgRequest, $wgUser, $wgLang;
 603                 $main = RequestContext::getMain();
 604
 605                 // Save current globals and main context
 606                 $glob = [
 607                         'title' => $wgTitle,
 608                         'output' => $wgOut,
 609                         'request' => $wgRequest,
 610                         'user' => $wgUser,
 611                         'language' => $wgLang,
 612                 ];
 613                 $ctx = [
 614                         'title' => $main->getTitle(),
 615                         'output' => $main->getOutput(),
 616                         'request' => $main->getRequest(),
 617                         'user' => $main->getUser(),
 618                         'language' => $main->getLanguage(),
 619                 ];
 620
 621                 // Override
 622                 $wgTitle = $title;
 623                 $wgOut = $context->getOutput();
 624                 $wgRequest = $context->getRequest();
 625                 $wgUser = $context->getUser();
 626                 $wgLang = $context->getLanguage();
 627                 $main->setTitle( $title );
 628                 $main->setOutput( $context->getOutput() );
 629                 $main->setRequest( $context->getRequest() );
 630                 $main->setUser( $context->getUser() );
 631                 $main->setLanguage( $context->getLanguage() );
 632
 633                 // The useful part
 634                 $ret = $this->executePath( $title, $context, true, $linkRenderer );
 635
 636                 // Restore old globals and context
 637                 $wgTitle = $glob['title'];
 638                 $wgOut = $glob['output'];
 639                 $wgRequest = $glob['request'];
 640                 $wgUser = $glob['user'];
 641                 $wgLang = $glob['language'];
 642                 $main->setTitle( $ctx['title'] );
 643                 $main->setOutput( $ctx['output'] );
 644                 $main->setRequest( $ctx['request'] );
 645                 $main->setUser( $ctx['user'] );
 646                 $main->setLanguage( $ctx['language'] );
 647
 648                 return $ret;
 649         }
 650
 651         /**
 652          * Get the local name for a specified canonical name
 653          *
 654          * @param string $name
 655          * @param string|bool $subpage
 656          * @return string
 657          */
 658         public function getLocalNameFor( $name, $subpage = false ) {
 659                 $aliases = $this->contLang->getSpecialPageAliases();
 660                 $aliasList = $this->getAliasList();
 661
 662                 // Find the first alias that maps back to $name
 663                 if ( isset( $aliases[$name] ) ) {
 664                         $found = false;
 665                         foreach ( $aliases[$name] as $alias ) {
 666                                 $caseFoldedAlias = $this->contLang->caseFold( $alias );
 667                                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 668                                 if ( isset( $aliasList[$caseFoldedAlias] ) &&
 669                                         $aliasList[$caseFoldedAlias] === $name
 670                                 ) {
 671                                         $name = $alias;
 672                                         $found = true;
 673                                         break;
 674                                 }
 675                         }
 676                         if ( !$found ) {
 677                                 wfWarn( "Did not find a usable alias for special page '$name'. " .
 678                                         "It seems all defined aliases conflict?" );
 679                         }
 680                 } else {
 681                         // Check if someone misspelled the correct casing
 682                         if ( is_array( $aliases ) ) {
 683                                 foreach ( $aliases as $n => $values ) {
 684                                         if ( strcasecmp( $name, $n ) === 0 ) {
 685                                                 wfWarn( "Found alias defined for $n when searching for " .
 686                                                         "special page aliases for $name. Case mismatch?" );
 687                                                 return $this->getLocalNameFor( $n, $subpage );
 688                                         }
 689                                 }
 690                         }
 691
 692                         wfWarn( "Did not find alias for special page '$name'. " .
 693                                 "Perhaps no aliases are defined for it?" );
 694                 }
 695
 696                 if ( $subpage !== false && !is_null( $subpage ) ) {
 697                         // Make sure it's in dbkey form
 698                         $subpage = str_replace( ' ', '_', $subpage );
 699                         $name = "$name/$subpage";
 700                 }
 701
 702                 return $this->contLang->ucfirst( $name );
 703         }
 704
 705         /**
 706          * Get a title for a given alias
 707          *
 708          * @param string $alias
 709          * @return Title|null Title or null if there is no such alias
 710          */
 711         public function getTitleForAlias( $alias ) {
 712                 list( $name, $subpage ) = $this->resolveAlias( $alias );
 713                 if ( $name != null ) {
 714                         return SpecialPage::getTitleFor( $name, $subpage );
 715                 }
 716
 717                 return null;
 718         }
 719 }