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 = array(
  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                 // Login/create account
  85                 'Userlogin' => 'LoginForm',
  86                 'CreateAccount' => 'SpecialCreateAccount',
  87
  88                 // Users and rights
  89                 'Block' => 'SpecialBlock',
  90                 'Unblock' => 'SpecialUnblock',
  91                 'BlockList' => 'SpecialBlockList',
  92                 'ChangePassword' => 'SpecialChangePassword',
  93                 'PasswordReset' => 'SpecialPasswordReset',
  94                 'DeletedContributions' => 'DeletedContributionsPage',
  95                 'Preferences' => 'SpecialPreferences',
  96                 'ResetTokens' => 'SpecialResetTokens',
  97                 'Contributions' => 'SpecialContributions',
  98                 'Listgrouprights' => 'SpecialListGroupRights',
  99                 'Listusers' => 'SpecialListUsers',
 100                 'Listadmins' => 'SpecialListAdmins',
 101                 'Listbots' => 'SpecialListBots',
 102                 'Userrights' => 'UserrightsPage',
 103                 'EditWatchlist' => 'SpecialEditWatchlist',
 104
 105                 // Recent changes and logs
 106                 'Newimages' => 'SpecialNewFiles',
 107                 'Log' => 'SpecialLog',
 108                 'Watchlist' => 'SpecialWatchlist',
 109                 'Newpages' => 'SpecialNewpages',
 110                 'Recentchanges' => 'SpecialRecentChanges',
 111                 'Recentchangeslinked' => 'SpecialRecentChangesLinked',
 112                 'Tags' => 'SpecialTags',
 113
 114                 // Media reports and uploads
 115                 'Listfiles' => 'SpecialListFiles',
 116                 'Filepath' => 'SpecialFilepath',
 117                 'MediaStatistics' => 'MediaStatisticsPage',
 118                 'MIMEsearch' => 'MIMEsearchPage',
 119                 'FileDuplicateSearch' => 'FileDuplicateSearchPage',
 120                 'Upload' => 'SpecialUpload',
 121                 'UploadStash' => 'SpecialUploadStash',
 122                 'ListDuplicatedFiles' => 'ListDuplicatedFilesPage',
 123
 124                 // Data and tools
 125                 'Statistics' => 'SpecialStatistics',
 126                 'Allmessages' => 'SpecialAllMessages',
 127                 'Version' => 'SpecialVersion',
 128                 'Lockdb' => 'SpecialLockdb',
 129                 'Unlockdb' => 'SpecialUnlockdb',
 130
 131                 // Redirecting special pages
 132                 'LinkSearch' => 'LinkSearchPage',
 133                 'Randompage' => 'RandomPage',
 134                 'RandomInCategory' => 'SpecialRandomInCategory',
 135                 'Randomredirect' => 'SpecialRandomredirect',
 136
 137                 // High use pages
 138                 'Mostlinkedcategories' => 'MostlinkedCategoriesPage',
 139                 'Mostimages' => 'MostimagesPage',
 140                 'Mostinterwikis' => 'MostinterwikisPage',
 141                 'Mostlinked' => 'MostlinkedPage',
 142                 'Mostlinkedtemplates' => 'MostlinkedTemplatesPage',
 143                 'Mostcategories' => 'MostcategoriesPage',
 144                 'Mostrevisions' => 'MostrevisionsPage',
 145
 146                 // Page tools
 147                 'ComparePages' => 'SpecialComparePages',
 148                 'Export' => 'SpecialExport',
 149                 'Import' => 'SpecialImport',
 150                 'Undelete' => 'SpecialUndelete',
 151                 'Whatlinkshere' => 'SpecialWhatLinksHere',
 152                 'MergeHistory' => 'SpecialMergeHistory',
 153                 'ExpandTemplates' => 'SpecialExpandTemplates',
 154
 155                 // Other
 156                 'Booksources' => 'SpecialBookSources',
 157
 158                 // Unlisted / redirects
 159                 'ApiHelp' => 'SpecialApiHelp',
 160                 'Blankpage' => 'SpecialBlankpage',
 161                 'Diff' => 'SpecialDiff',
 162                 'EditTags' => 'SpecialEditTags',
 163                 'Emailuser' => 'SpecialEmailUser',
 164                 'Movepage' => 'MovePageForm',
 165                 'Mycontributions' => 'SpecialMycontributions',
 166                 'MyLanguage' => 'SpecialMyLanguage',
 167                 'Mypage' => 'SpecialMypage',
 168                 'Mytalk' => 'SpecialMytalk',
 169                 'Myuploads' => 'SpecialMyuploads',
 170                 'AllMyUploads' => 'SpecialAllMyUploads',
 171                 'PermanentLink' => 'SpecialPermanentLink',
 172                 'Redirect' => 'SpecialRedirect',
 173                 'Revisiondelete' => 'SpecialRevisionDelete',
 174                 'RunJobs' => 'SpecialRunJobs',
 175                 'Specialpages' => 'SpecialSpecialpages',
 176                 'Userlogout' => 'SpecialUserlogout',
 177         );
 178
 179         private static $list;
 180         private static $aliases;
 181
 182         /**
 183          * Reset the internal list of special pages. Useful when changing $wgSpecialPages after
 184          * the internal list has already been initialized, e.g. during testing.
 185          */
 186         public static function resetList() {
 187                 self::$list = null;
 188                 self::$aliases = null;
 189         }
 190
 191         /**
 192          * Returns a list of canonical special page names.
 193          * May be used to iterate over all registered special pages.
 194          *
 195          * @return string[]
 196          */
 197         public static function getNames() {
 198                 return array_keys( self::getPageList() );
 199         }
 200
 201         /**
 202          * Get the special page list as an array
 203          *
 204          * @deprecated since 1.24, use getNames() instead.
 205          * @return array
 206          */
 207         public static function getList() {
 208                 wfDeprecated( __FUNCTION__, '1.24' );
 209                 return self::getPageList();
 210         }
 211
 212         /**
 213          * Get the special page list as an array
 214          *
 215          * @return array
 216          */
 217         private static function getPageList() {
 218                 global $wgSpecialPages;
 219                 global $wgDisableInternalSearch, $wgEmailAuthentication;
 220                 global $wgEnableEmail, $wgEnableJavaScriptTest;
 221                 global $wgPageLanguageUseDB;
 222
 223                 if ( !is_array( self::$list ) ) {
 224
 225                         self::$list = self::$coreList;
 226
 227                         if ( !$wgDisableInternalSearch ) {
 228                                 self::$list['Search'] = 'SpecialSearch';
 229                         }
 230
 231                         if ( $wgEmailAuthentication ) {
 232                                 self::$list['Confirmemail'] = 'EmailConfirmation';
 233                                 self::$list['Invalidateemail'] = 'EmailInvalidation';
 234                         }
 235
 236                         if ( $wgEnableEmail ) {
 237                                 self::$list['ChangeEmail'] = 'SpecialChangeEmail';
 238                         }
 239
 240                         if ( $wgEnableJavaScriptTest ) {
 241                                 self::$list['JavaScriptTest'] = 'SpecialJavaScriptTest';
 242                         }
 243
 244                         if ( $wgPageLanguageUseDB ) {
 245                                 self::$list['PageLanguage'] = 'SpecialPageLanguage';
 246                         }
 247
 248                         self::$list['Activeusers'] = 'SpecialActiveUsers';
 249
 250                         // Add extension special pages
 251                         self::$list = array_merge( self::$list, $wgSpecialPages );
 252
 253                         // This hook can be used to disable unwanted core special pages
 254                         // or conditionally register special pages.
 255                         Hooks::run( 'SpecialPage_initList', array( &self::$list ) );
 256
 257                 }
 258
 259                 return self::$list;
 260         }
 261
 262         /**
 263          * Initialise and return the list of special page aliases. Returns an array where
 264          * the key is an alias, and the value is the canonical name of the special page.
 265          * All registered special pages are guaranteed to map to themselves.
 266          * @return array
 267          */
 268         private static function getAliasList() {
 269                 if ( is_null( self::$aliases ) ) {
 270                         global $wgContLang;
 271                         $aliases = $wgContLang->getSpecialPageAliases();
 272                         $pageList = self::getPageList();
 273
 274                         self::$aliases = array();
 275                         $keepAlias = array();
 276
 277                         // Force every canonical name to be an alias for itself.
 278                         foreach ( $pageList as $name => $stuff ) {
 279                                 $caseFoldedAlias = $wgContLang->caseFold( $name );
 280                                 self::$aliases[$caseFoldedAlias] = $name;
 281                                 $keepAlias[$caseFoldedAlias] = 'canonical';
 282                         }
 283
 284                         // Check for $aliases being an array since Language::getSpecialPageAliases can return null
 285                         if ( is_array( $aliases ) ) {
 286                                 foreach ( $aliases as $realName => $aliasList ) {
 287                                         $aliasList = array_values( $aliasList );
 288                                         foreach ( $aliasList as $i => $alias ) {
 289                                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 290
 291                                                 if ( isset( self::$aliases[$caseFoldedAlias] ) &&
 292                                                         $realName === self::$aliases[$caseFoldedAlias]
 293                                                 ) {
 294                                                         // Ignore same-realName conflicts
 295                                                         continue;
 296                                                 }
 297
 298                                                 if ( !isset( $keepAlias[$caseFoldedAlias] ) ) {
 299                                                         self::$aliases[$caseFoldedAlias] = $realName;
 300                                                         if ( !$i ) {
 301                                                                 $keepAlias[$caseFoldedAlias] = 'first';
 302                                                         }
 303                                                 } elseif ( !$i ) {
 304                                                         wfWarn( "First alias '$alias' for $realName conflicts with " .
 305                                                                 "{$keepAlias[$caseFoldedAlias]} alias for " .
 306                                                                 self::$aliases[$caseFoldedAlias]
 307                                                         );
 308                                                 }
 309                                         }
 310                                 }
 311                         }
 312                 }
 313
 314                 return self::$aliases;
 315         }
 316
 317         /**
 318          * Given a special page name with a possible subpage, return an array
 319          * where the first element is the special page name and the second is the
 320          * subpage.
 321          *
 322          * @param string $alias
 323          * @return array Array( String, String|null ), or array( null, null ) if the page is invalid
 324          */
 325         public static function resolveAlias( $alias ) {
 326                 global $wgContLang;
 327                 $bits = explode( '/', $alias, 2 );
 328
 329                 $caseFoldedAlias = $wgContLang->caseFold( $bits[0] );
 330                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 331                 $aliases = self::getAliasList();
 332                 if ( isset( $aliases[$caseFoldedAlias] ) ) {
 333                         $name = $aliases[$caseFoldedAlias];
 334                 } else {
 335                         return array( null, null );
 336                 }
 337
 338                 if ( !isset( $bits[1] ) ) { // bug 2087
 339                         $par = null;
 340                 } else {
 341                         $par = $bits[1];
 342                 }
 343
 344                 return array( $name, $par );
 345         }
 346
 347         /**
 348          * Check if a given name exist as a special page or as a special page alias
 349          *
 350          * @param string $name Name of a special page
 351          * @return bool True if a special page exists with this name
 352          */
 353         public static function exists( $name ) {
 354                 list( $title, /*...*/ ) = self::resolveAlias( $name );
 355
 356                 $specialPageList = self::getPageList();
 357                 return isset( $specialPageList[$title] );
 358         }
 359
 360         /**
 361          * Find the object with a given name and return it (or NULL)
 362          *
 363          * @param string $name Special page name, may be localised and/or an alias
 364          * @return SpecialPage|null SpecialPage object or null if the page doesn't exist
 365          */
 366         public static function getPage( $name ) {
 367                 list( $realName, /*...*/ ) = self::resolveAlias( $name );
 368
 369                 $specialPageList = self::getPageList();
 370
 371                 if ( isset( $specialPageList[$realName] ) ) {
 372                         $rec = $specialPageList[$realName];
 373
 374                         if ( is_callable( $rec ) ) {
 375                                 // Use callback to instantiate the special page
 376                                 $page = call_user_func( $rec );
 377                         } elseif ( is_string( $rec ) ) {
 378                                 $className = $rec;
 379                                 $page = new $className;
 380                         } elseif ( is_array( $rec ) ) {
 381                                 $className = array_shift( $rec );
 382                                 // @deprecated, officially since 1.18, unofficially since forever
 383                                 wfDeprecated( "Array syntax for \$wgSpecialPages is deprecated ($className), " .
 384                                         "define a subclass of SpecialPage instead.", '1.18' );
 385                                 $page = ObjectFactory::getObjectFromSpec( array(
 386                                         'class' => $className,
 387                                         'args' => $rec,
 388                                         'closure_expansion' => false,
 389                                 ) );
 390                         } elseif ( $rec instanceof SpecialPage ) {
 391                                 $page = $rec; //XXX: we should deep clone here
 392                         } else {
 393                                 $page = null;
 394                         }
 395
 396                         if ( $page instanceof SpecialPage ) {
 397                                 return $page;
 398                         } else {
 399                                 // It's not a classname, nor a callback, nor a legacy constructor array,
 400                                 // nor a special page object. Give up.
 401                                 wfLogWarning( "Cannot instantiate special page $realName: bad spec!" );
 402                                 return null;
 403                         }
 404
 405                 } else {
 406                         return null;
 407                 }
 408         }
 409
 410         /**
 411          * Return categorised listable special pages which are available
 412          * for the current user, and everyone.
 413          *
 414          * @param User $user User object to check permissions, $wgUser will be used
 415          *        if not provided
 416          * @return array ( string => Specialpage )
 417          */
 418         public static function getUsablePages( User $user = null ) {
 419                 $pages = array();
 420                 if ( $user === null ) {
 421                         global $wgUser;
 422                         $user = $wgUser;
 423                 }
 424                 foreach ( self::getPageList() as $name => $rec ) {
 425                         $page = self::getPage( $name );
 426                         if ( $page ) { // not null
 427                                 $page->setContext( RequestContext::getMain() );
 428                                 if ( $page->isListed()
 429                                         && ( !$page->isRestricted() || $page->userCanExecute( $user ) )
 430                                 ) {
 431                                         $pages[$name] = $page;
 432                                 }
 433                         }
 434                 }
 435
 436                 return $pages;
 437         }
 438
 439         /**
 440          * Return categorised listable special pages for all users
 441          *
 442          * @return array ( string => Specialpage )
 443          */
 444         public static function getRegularPages() {
 445                 $pages = array();
 446                 foreach ( self::getPageList() as $name => $rec ) {
 447                         $page = self::getPage( $name );
 448                         if ( $page->isListed() && !$page->isRestricted() ) {
 449                                 $pages[$name] = $page;
 450                         }
 451                 }
 452
 453                 return $pages;
 454         }
 455
 456         /**
 457          * Return categorised listable special pages which are available
 458          * for the current user, but not for everyone
 459          *
 460          * @param User|null $user User object to use or null for $wgUser
 461          * @return array ( string => Specialpage )
 462          */
 463         public static function getRestrictedPages( User $user = null ) {
 464                 $pages = array();
 465                 if ( $user === null ) {
 466                         global $wgUser;
 467                         $user = $wgUser;
 468                 }
 469                 foreach ( self::getPageList() as $name => $rec ) {
 470                         $page = self::getPage( $name );
 471                         if (
 472                                 $page->isListed()
 473                                 && $page->isRestricted()
 474                                 && $page->userCanExecute( $user )
 475                         ) {
 476                                 $pages[$name] = $page;
 477                         }
 478                 }
 479
 480                 return $pages;
 481         }
 482
 483         /**
 484          * Execute a special page path.
 485          * The path may contain parameters, e.g. Special:Name/Params
 486          * Extracts the special page name and call the execute method, passing the parameters
 487          *
 488          * Returns a title object if the page is redirected, false if there was no such special
 489          * page, and true if it was successful.
 490          *
 491          * @param Title $title
 492          * @param IContextSource $context
 493          * @param bool $including Bool output is being captured for use in {{special:whatever}}
 494          *
 495          * @return bool
 496          */
 497         public static function executePath( Title &$title, IContextSource &$context, $including = false ) {
 498
 499                 // @todo FIXME: Redirects broken due to this call
 500                 $bits = explode( '/', $title->getDBkey(), 2 );
 501                 $name = $bits[0];
 502                 if ( !isset( $bits[1] ) ) { // bug 2087
 503                         $par = null;
 504                 } else {
 505                         $par = $bits[1];
 506                 }
 507                 $page = self::getPage( $name );
 508                 // Nonexistent?
 509                 if ( !$page ) {
 510                         $context->getOutput()->setArticleRelated( false );
 511                         $context->getOutput()->setRobotPolicy( 'noindex,nofollow' );
 512
 513                         global $wgSend404Code;
 514                         if ( $wgSend404Code ) {
 515                                 $context->getOutput()->setStatusCode( 404 );
 516                         }
 517
 518                         $context->getOutput()->showErrorPage( 'nosuchspecialpage', 'nospecialpagetext' );
 519
 520                         return false;
 521                 }
 522
 523                 // Page exists, set the context
 524                 $page->setContext( $context );
 525
 526                 if ( !$including ) {
 527                         // Redirect to canonical alias for GET commands
 528                         // Not for POST, we'd lose the post data, so it's best to just distribute
 529                         // the request. Such POST requests are possible for old extensions that
 530                         // generate self-links without being aware that their default name has
 531                         // changed.
 532                         if ( $name != $page->getLocalName() && !$context->getRequest()->wasPosted() ) {
 533                                 $query = $context->getRequest()->getQueryValues();
 534                                 unset( $query['title'] );
 535                                 $title = $page->getPageTitle( $par );
 536                                 $url = $title->getFullURL( $query );
 537                                 $context->getOutput()->redirect( $url );
 538
 539                                 return $title;
 540                         } else {
 541                                 $context->setTitle( $page->getPageTitle( $par ) );
 542                         }
 543                 } elseif ( !$page->isIncludable() ) {
 544                         return false;
 545                 }
 546
 547                 $page->including( $including );
 548
 549                 // Execute special page
 550                 $page->run( $par );
 551
 552                 return true;
 553         }
 554
 555         /**
 556          * Just like executePath() but will override global variables and execute
 557          * the page in "inclusion" mode. Returns true if the execution was
 558          * successful or false if there was no such special page, or a title object
 559          * if it was a redirect.
 560          *
 561          * Also saves the current $wgTitle, $wgOut, $wgRequest, $wgUser and $wgLang
 562          * variables so that the special page will get the context it'd expect on a
 563          * normal request, and then restores them to their previous values after.
 564          *
 565          * @param Title $title
 566          * @param IContextSource $context
 567          * @return string HTML fragment
 568          */
 569         public static function capturePath( Title $title, IContextSource $context ) {
 570                 global $wgOut, $wgTitle, $wgRequest, $wgUser, $wgLang;
 571
 572                 // Save current globals
 573                 $oldTitle = $wgTitle;
 574                 $oldOut = $wgOut;
 575                 $oldRequest = $wgRequest;
 576                 $oldUser = $wgUser;
 577                 $oldLang = $wgLang;
 578
 579                 // Set the globals to the current context
 580                 $wgTitle = $title;
 581                 $wgOut = $context->getOutput();
 582                 $wgRequest = $context->getRequest();
 583                 $wgUser = $context->getUser();
 584                 $wgLang = $context->getLanguage();
 585
 586                 // The useful part
 587                 $ret = self::executePath( $title, $context, true );
 588
 589                 // And restore the old globals
 590                 $wgTitle = $oldTitle;
 591                 $wgOut = $oldOut;
 592                 $wgRequest = $oldRequest;
 593                 $wgUser = $oldUser;
 594                 $wgLang = $oldLang;
 595
 596                 return $ret;
 597         }
 598
 599         /**
 600          * Get the local name for a specified canonical name
 601          *
 602          * @param string $name
 603          * @param string|bool $subpage
 604          * @return string
 605          */
 606         public static function getLocalNameFor( $name, $subpage = false ) {
 607                 global $wgContLang;
 608                 $aliases = $wgContLang->getSpecialPageAliases();
 609                 $aliasList = self::getAliasList();
 610
 611                 // Find the first alias that maps back to $name
 612                 if ( isset( $aliases[$name] ) ) {
 613                         $found = false;
 614                         foreach ( $aliases[$name] as $alias ) {
 615                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 616                                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 617                                 if ( isset( $aliasList[$caseFoldedAlias] ) &&
 618                                         $aliasList[$caseFoldedAlias] === $name
 619                                 ) {
 620                                         $name = $alias;
 621                                         $found = true;
 622                                         break;
 623                                 }
 624                         }
 625                         if ( !$found ) {
 626                                 wfWarn( "Did not find a usable alias for special page '$name'. " .
 627                                         "It seems all defined aliases conflict?" );
 628                         }
 629                 } else {
 630                         // Check if someone misspelled the correct casing
 631                         if ( is_array( $aliases ) ) {
 632                                 foreach ( $aliases as $n => $values ) {
 633                                         if ( strcasecmp( $name, $n ) === 0 ) {
 634                                                 wfWarn( "Found alias defined for $n when searching for " .
 635                                                         "special page aliases for $name. Case mismatch?" );
 636                                                 return self::getLocalNameFor( $n, $subpage );
 637                                         }
 638                                 }
 639                         }
 640
 641                         wfWarn( "Did not find alias for special page '$name'. " .
 642                                 "Perhaps no aliases are defined for it?" );
 643                 }
 644
 645                 if ( $subpage !== false && !is_null( $subpage ) ) {
 646                         $name = "$name/$subpage";
 647                 }
 648
 649                 return $wgContLang->ucfirst( $name );
 650         }
 651
 652         /**
 653          * Get a title for a given alias
 654          *
 655          * @param string $alias
 656          * @return Title|null Title or null if there is no such alias
 657          */
 658         public static function getTitleForAlias( $alias ) {
 659                 list( $name, $subpage ) = self::resolveAlias( $alias );
 660                 if ( $name != null ) {
 661                         return SpecialPage::getTitleFor( $name, $subpage );
 662                 } else {
 663                         return null;
 664                 }
 665         }
 666 }