includes/specialpage/SpecialPage.php

   1 <?php
   2 /**
   3  * Parent class for all special pages.
   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  */
  23
  24 use MediaWiki\Auth\AuthManager;
  25 use MediaWiki\Linker\LinkRenderer;
  26 use MediaWiki\MediaWikiServices;
  27
  28 /**
  29  * Parent class for all special pages.
  30  *
  31  * Includes some static functions for handling the special page list deprecated
  32  * in favor of SpecialPageFactory.
  33  *
  34  * @ingroup SpecialPage
  35  */
  36 class SpecialPage implements MessageLocalizer {
  37         // The canonical name of this special page
  38         // Also used for the default <h1> heading, @see getDescription()
  39         protected $mName;
  40
  41         // The local name of this special page
  42         private $mLocalName;
  43
  44         // Minimum user level required to access this page, or "" for anyone.
  45         // Also used to categorise the pages in Special:Specialpages
  46         protected $mRestriction;
  47
  48         // Listed in Special:Specialpages?
  49         private $mListed;
  50
  51         // Whether or not this special page is being included from an article
  52         protected $mIncluding;
  53
  54         // Whether the special page can be included in an article
  55         protected $mIncludable;
  56
  57         /**
  58          * Current request context
  59          * @var IContextSource
  60          */
  61         protected $mContext;
  62
  63         /**
  64          * @var \MediaWiki\Linker\LinkRenderer|null
  65          */
  66         private $linkRenderer;
  67
  68         /**
  69          * Get a localised Title object for a specified special page name
  70          * If you don't need a full Title object, consider using TitleValue through
  71          * getTitleValueFor() below.
  72          *
  73          * @since 1.9
  74          * @since 1.21 $fragment parameter added
  75          *
  76          * @param string $name
  77          * @param string|bool $subpage Subpage string, or false to not use a subpage
  78          * @param string $fragment The link fragment (after the "#")
  79          * @return Title
  80          * @throws MWException
  81          */
  82         public static function getTitleFor( $name, $subpage = false, $fragment = '' ) {
  83                 return Title::newFromTitleValue(
  84                         self::getTitleValueFor( $name, $subpage, $fragment )
  85                 );
  86         }
  87
  88         /**
  89          * Get a localised TitleValue object for a specified special page name
  90          *
  91          * @since 1.28
  92          * @param string $name
  93          * @param string|bool $subpage Subpage string, or false to not use a subpage
  94          * @param string $fragment The link fragment (after the "#")
  95          * @return TitleValue
  96          */
  97         public static function getTitleValueFor( $name, $subpage = false, $fragment = '' ) {
  98                 $name = SpecialPageFactory::getLocalNameFor( $name, $subpage );
  99
 100                 return new TitleValue( NS_SPECIAL, $name, $fragment );
 101         }
 102
 103         /**
 104          * Get a localised Title object for a page name with a possibly unvalidated subpage
 105          *
 106          * @param string $name
 107          * @param string|bool $subpage Subpage string, or false to not use a subpage
 108          * @return Title|null Title object or null if the page doesn't exist
 109          */
 110         public static function getSafeTitleFor( $name, $subpage = false ) {
 111                 $name = SpecialPageFactory::getLocalNameFor( $name, $subpage );
 112                 if ( $name ) {
 113                         return Title::makeTitleSafe( NS_SPECIAL, $name );
 114                 } else {
 115                         return null;
 116                 }
 117         }
 118
 119         /**
 120          * Default constructor for special pages
 121          * Derivative classes should call this from their constructor
 122          *     Note that if the user does not have the required level, an error message will
 123          *     be displayed by the default execute() method, without the global function ever
 124          *     being called.
 125          *
 126          *     If you override execute(), you can recover the default behavior with userCanExecute()
 127          *     and displayRestrictionError()
 128          *
 129          * @param string $name Name of the special page, as seen in links and URLs
 130          * @param string $restriction User right required, e.g. "block" or "delete"
 131          * @param bool $listed Whether the page is listed in Special:Specialpages
 132          * @param callable|bool $function Unused
 133          * @param string $file Unused
 134          * @param bool $includable Whether the page can be included in normal pages
 135          */
 136         public function __construct(
 137                 $name = '', $restriction = '', $listed = true,
 138                 $function = false, $file = '', $includable = false
 139         ) {
 140                 $this->mName = $name;
 141                 $this->mRestriction = $restriction;
 142                 $this->mListed = $listed;
 143                 $this->mIncludable = $includable;
 144         }
 145
 146         /**
 147          * Get the name of this Special Page.
 148          * @return string
 149          */
 150         function getName() {
 151                 return $this->mName;
 152         }
 153
 154         /**
 155          * Get the permission that a user must have to execute this page
 156          * @return string
 157          */
 158         function getRestriction() {
 159                 return $this->mRestriction;
 160         }
 161
 162         // @todo FIXME: Decide which syntax to use for this, and stick to it
 163         /**
 164          * Whether this special page is listed in Special:SpecialPages
 165          * @since 1.3 (r3583)
 166          * @return bool
 167          */
 168         function isListed() {
 169                 return $this->mListed;
 170         }
 171
 172         /**
 173          * Set whether this page is listed in Special:Specialpages, at run-time
 174          * @since 1.3
 175          * @param bool $listed
 176          * @return bool
 177          */
 178         function setListed( $listed ) {
 179                 return wfSetVar( $this->mListed, $listed );
 180         }
 181
 182         /**
 183          * Get or set whether this special page is listed in Special:SpecialPages
 184          * @since 1.6
 185          * @param bool $x
 186          * @return bool
 187          */
 188         function listed( $x = null ) {
 189                 return wfSetVar( $this->mListed, $x );
 190         }
 191
 192         /**
 193          * Whether it's allowed to transclude the special page via {{Special:Foo/params}}
 194          * @return bool
 195          */
 196         public function isIncludable() {
 197                 return $this->mIncludable;
 198         }
 199
 200         /**
 201          * How long to cache page when it is being included.
 202          *
 203          * @note If cache time is not 0, then the current user becomes an anon
 204          *   if you want to do any per-user customizations, than this method
 205          *   must be overriden to return 0.
 206          * @since 1.26
 207          * @return int Time in seconds, 0 to disable caching altogether,
 208          *  false to use the parent page's cache settings
 209          */
 210         public function maxIncludeCacheTime() {
 211                 return $this->getConfig()->get( 'MiserMode' ) ? $this->getCacheTTL() : 0;
 212         }
 213
 214         /**
 215          * @return int Seconds that this page can be cached
 216          */
 217         protected function getCacheTTL() {
 218                 return 60 * 60;
 219         }
 220
 221         /**
 222          * Whether the special page is being evaluated via transclusion
 223          * @param bool $x
 224          * @return bool
 225          */
 226         function including( $x = null ) {
 227                 return wfSetVar( $this->mIncluding, $x );
 228         }
 229
 230         /**
 231          * Get the localised name of the special page
 232          * @return string
 233          */
 234         function getLocalName() {
 235                 if ( !isset( $this->mLocalName ) ) {
 236                         $this->mLocalName = SpecialPageFactory::getLocalNameFor( $this->mName );
 237                 }
 238
 239                 return $this->mLocalName;
 240         }
 241
 242         /**
 243          * Is this page expensive (for some definition of expensive)?
 244          * Expensive pages are disabled or cached in miser mode.  Originally used
 245          * (and still overridden) by QueryPage and subclasses, moved here so that
 246          * Special:SpecialPages can safely call it for all special pages.
 247          *
 248          * @return bool
 249          */
 250         public function isExpensive() {
 251                 return false;
 252         }
 253
 254         /**
 255          * Is this page cached?
 256          * Expensive pages are cached or disabled in miser mode.
 257          * Used by QueryPage and subclasses, moved here so that
 258          * Special:SpecialPages can safely call it for all special pages.
 259          *
 260          * @return bool
 261          * @since 1.21
 262          */
 263         public function isCached() {
 264                 return false;
 265         }
 266
 267         /**
 268          * Can be overridden by subclasses with more complicated permissions
 269          * schemes.
 270          *
 271          * @return bool Should the page be displayed with the restricted-access
 272          *   pages?
 273          */
 274         public function isRestricted() {
 275                 // DWIM: If anons can do something, then it is not restricted
 276                 return $this->mRestriction != '' && !User::groupHasPermission( '*', $this->mRestriction );
 277         }
 278
 279         /**
 280          * Checks if the given user (identified by an object) can execute this
 281          * special page (as defined by $mRestriction).  Can be overridden by sub-
 282          * classes with more complicated permissions schemes.
 283          *
 284          * @param User $user The user to check
 285          * @return bool Does the user have permission to view the page?
 286          */
 287         public function userCanExecute( User $user ) {
 288                 return $user->isAllowed( $this->mRestriction );
 289         }
 290
 291         /**
 292          * Output an error message telling the user what access level they have to have
 293          * @throws PermissionsError
 294          */
 295         function displayRestrictionError() {
 296                 throw new PermissionsError( $this->mRestriction );
 297         }
 298
 299         /**
 300          * Checks if userCanExecute, and if not throws a PermissionsError
 301          *
 302          * @since 1.19
 303          * @return void
 304          * @throws PermissionsError
 305          */
 306         public function checkPermissions() {
 307                 if ( !$this->userCanExecute( $this->getUser() ) ) {
 308                         $this->displayRestrictionError();
 309                 }
 310         }
 311
 312         /**
 313          * If the wiki is currently in readonly mode, throws a ReadOnlyError
 314          *
 315          * @since 1.19
 316          * @return void
 317          * @throws ReadOnlyError
 318          */
 319         public function checkReadOnly() {
 320                 if ( wfReadOnly() ) {
 321                         throw new ReadOnlyError;
 322                 }
 323         }
 324
 325         /**
 326          * If the user is not logged in, throws UserNotLoggedIn error
 327          *
 328          * The user will be redirected to Special:Userlogin with the given message as an error on
 329          * the form.
 330          *
 331          * @since 1.23
 332          * @param string $reasonMsg [optional] Message key to be displayed on login page
 333          * @param string $titleMsg [optional] Passed on to UserNotLoggedIn constructor
 334          * @throws UserNotLoggedIn
 335          */
 336         public function requireLogin(
 337                 $reasonMsg = 'exception-nologin-text', $titleMsg = 'exception-nologin'
 338         ) {
 339                 if ( $this->getUser()->isAnon() ) {
 340                         throw new UserNotLoggedIn( $reasonMsg, $titleMsg );
 341                 }
 342         }
 343
 344         /**
 345          * Tells if the special page does something security-sensitive and needs extra defense against
 346          * a stolen account (e.g. a reauthentication). What exactly that will mean is decided by the
 347          * authentication framework.
 348          * @return bool|string False or the argument for AuthManager::securitySensitiveOperationStatus().
 349          *   Typically a special page needing elevated security would return its name here.
 350          */
 351         protected function getLoginSecurityLevel() {
 352                 return false;
 353         }
 354
 355         /**
 356          * Verifies that the user meets the security level, possibly reauthenticating them in the process.
 357          *
 358          * This should be used when the page does something security-sensitive and needs extra defense
 359          * against a stolen account (e.g. a reauthentication). The authentication framework will make
 360          * an extra effort to make sure the user account is not compromised. What that exactly means
 361          * will depend on the system and user settings; e.g. the user might be required to log in again
 362          * unless their last login happened recently, or they might be given a second-factor challenge.
 363          *
 364          * Calling this method will result in one if these actions:
 365          * - return true: all good.
 366          * - return false and set a redirect: caller should abort; the redirect will take the user
 367          *   to the login page for reauthentication, and back.
 368          * - throw an exception if there is no way for the user to meet the requirements without using
 369          *   a different access method (e.g. this functionality is only available from a specific IP).
 370          *
 371          * Note that this does not in any way check that the user is authorized to use this special page
 372          * (use checkPermissions() for that).
 373          *
 374          * @param string $level A security level. Can be an arbitrary string, defaults to the page name.
 375          * @return bool False means a redirect to the reauthentication page has been set and processing
 376          *   of the special page should be aborted.
 377          * @throws ErrorPageError If the security level cannot be met, even with reauthentication.
 378          */
 379         protected function checkLoginSecurityLevel( $level = null ) {
 380                 $level = $level ?: $this->getName();
 381                 $securityStatus = AuthManager::singleton()->securitySensitiveOperationStatus( $level );
 382                 if ( $securityStatus === AuthManager::SEC_OK ) {
 383                         return true;
 384                 } elseif ( $securityStatus === AuthManager::SEC_REAUTH ) {
 385                         $request = $this->getRequest();
 386                         $title = self::getTitleFor( 'Userlogin' );
 387                         $query = [
 388                                 'returnto' => $this->getFullTitle()->getPrefixedDBkey(),
 389                                 'returntoquery' => wfArrayToCgi( array_diff_key( $request->getQueryValues(),
 390                                         [ 'title' => true ] ) ),
 391                                 'force' => $level,
 392                         ];
 393                         $url = $title->getFullURL( $query, false, PROTO_HTTPS );
 394
 395                         $this->getOutput()->redirect( $url );
 396                         return false;
 397                 }
 398
 399                 $titleMessage = wfMessage( 'specialpage-securitylevel-not-allowed-title' );
 400                 $errorMessage = wfMessage( 'specialpage-securitylevel-not-allowed' );
 401                 throw new ErrorPageError( $titleMessage, $errorMessage );
 402         }
 403
 404         /**
 405          * Return an array of subpages beginning with $search that this special page will accept.
 406          *
 407          * For example, if a page supports subpages "foo", "bar" and "baz" (as in Special:PageName/foo,
 408          * etc.):
 409          *
 410          *   - `prefixSearchSubpages( "ba" )` should return `array( "bar", "baz" )`
 411          *   - `prefixSearchSubpages( "f" )` should return `array( "foo" )`
 412          *   - `prefixSearchSubpages( "z" )` should return `array()`
 413          *   - `prefixSearchSubpages( "" )` should return `array( foo", "bar", "baz" )`
 414          *
 415          * @param string $search Prefix to search for
 416          * @param int $limit Maximum number of results to return (usually 10)
 417          * @param int $offset Number of results to skip (usually 0)
 418          * @return string[] Matching subpages
 419          */
 420         public function prefixSearchSubpages( $search, $limit, $offset ) {
 421                 $subpages = $this->getSubpagesForPrefixSearch();
 422                 if ( !$subpages ) {
 423                         return [];
 424                 }
 425
 426                 return self::prefixSearchArray( $search, $limit, $subpages, $offset );
 427         }
 428
 429         /**
 430          * Return an array of subpages that this special page will accept for prefix
 431          * searches. If this method requires a query you might instead want to implement
 432          * prefixSearchSubpages() directly so you can support $limit and $offset. This
 433          * method is better for static-ish lists of things.
 434          *
 435          * @return string[] subpages to search from
 436          */
 437         protected function getSubpagesForPrefixSearch() {
 438                 return [];
 439         }
 440
 441         /**
 442          * Perform a regular substring search for prefixSearchSubpages
 443          * @param string $search Prefix to search for
 444          * @param int $limit Maximum number of results to return (usually 10)
 445          * @param int $offset Number of results to skip (usually 0)
 446          * @return string[] Matching subpages
 447          */
 448         protected function prefixSearchString( $search, $limit, $offset ) {
 449                 $title = Title::newFromText( $search );
 450                 if ( !$title || !$title->canExist() ) {
 451                         // No prefix suggestion in special and media namespace
 452                         return [];
 453                 }
 454
 455                 $searchEngine = MediaWikiServices::getInstance()->newSearchEngine();
 456                 $searchEngine->setLimitOffset( $limit, $offset );
 457                 $searchEngine->setNamespaces( [] );
 458                 $result = $searchEngine->defaultPrefixSearch( $search );
 459                 return array_map( function ( Title $t ) {
 460                         return $t->getPrefixedText();
 461                 }, $result );
 462         }
 463
 464         /**
 465          * Helper function for implementations of prefixSearchSubpages() that
 466          * filter the values in memory (as opposed to making a query).
 467          *
 468          * @since 1.24
 469          * @param string $search
 470          * @param int $limit
 471          * @param array $subpages
 472          * @param int $offset
 473          * @return string[]
 474          */
 475         protected static function prefixSearchArray( $search, $limit, array $subpages, $offset ) {
 476                 $escaped = preg_quote( $search, '/' );
 477                 return array_slice( preg_grep( "/^$escaped/i",
 478                         array_slice( $subpages, $offset ) ), 0, $limit );
 479         }
 480
 481         /**
 482          * Sets headers - this should be called from the execute() method of all derived classes!
 483          */
 484         function setHeaders() {
 485                 $out = $this->getOutput();
 486                 $out->setArticleRelated( false );
 487                 $out->setRobotPolicy( $this->getRobotPolicy() );
 488                 $out->setPageTitle( $this->getDescription() );
 489                 if ( $this->getConfig()->get( 'UseMediaWikiUIEverywhere' ) ) {
 490                         $out->addModuleStyles( [
 491                                 'mediawiki.ui.input',
 492                                 'mediawiki.ui.radio',
 493                                 'mediawiki.ui.checkbox',
 494                         ] );
 495                 }
 496         }
 497
 498         /**
 499          * Entry point.
 500          *
 501          * @since 1.20
 502          *
 503          * @param string|null $subPage
 504          */
 505         final public function run( $subPage ) {
 506                 /**
 507                  * Gets called before @see SpecialPage::execute.
 508                  * Return false to prevent calling execute() (since 1.27+).
 509                  *
 510                  * @since 1.20
 511                  *
 512                  * @param SpecialPage $this
 513                  * @param string|null $subPage
 514                  */
 515                 if ( !Hooks::run( 'SpecialPageBeforeExecute', [ $this, $subPage ] ) ) {
 516                         return;
 517                 }
 518
 519                 if ( $this->beforeExecute( $subPage ) === false ) {
 520                         return;
 521                 }
 522                 $this->execute( $subPage );
 523                 $this->afterExecute( $subPage );
 524
 525                 /**
 526                  * Gets called after @see SpecialPage::execute.
 527                  *
 528                  * @since 1.20
 529                  *
 530                  * @param SpecialPage $this
 531                  * @param string|null $subPage
 532                  */
 533                 Hooks::run( 'SpecialPageAfterExecute', [ $this, $subPage ] );
 534         }
 535
 536         /**
 537          * Gets called before @see SpecialPage::execute.
 538          * Return false to prevent calling execute() (since 1.27+).
 539          *
 540          * @since 1.20
 541          *
 542          * @param string|null $subPage
 543          * @return bool|void
 544          */
 545         protected function beforeExecute( $subPage ) {
 546                 // No-op
 547         }
 548
 549         /**
 550          * Gets called after @see SpecialPage::execute.
 551          *
 552          * @since 1.20
 553          *
 554          * @param string|null $subPage
 555          */
 556         protected function afterExecute( $subPage ) {
 557                 // No-op
 558         }
 559
 560         /**
 561          * Default execute method
 562          * Checks user permissions
 563          *
 564          * This must be overridden by subclasses; it will be made abstract in a future version
 565          *
 566          * @param string|null $subPage
 567          */
 568         public function execute( $subPage ) {
 569                 $this->setHeaders();
 570                 $this->checkPermissions();
 571                 $this->checkLoginSecurityLevel( $this->getLoginSecurityLevel() );
 572                 $this->outputHeader();
 573         }
 574
 575         /**
 576          * Outputs a summary message on top of special pages
 577          * Per default the message key is the canonical name of the special page
 578          * May be overridden, i.e. by extensions to stick with the naming conventions
 579          * for message keys: 'extensionname-xxx'
 580          *
 581          * @param string $summaryMessageKey Message key of the summary
 582          */
 583         function outputHeader( $summaryMessageKey = '' ) {
 584                 global $wgContLang;
 585
 586                 if ( $summaryMessageKey == '' ) {
 587                         $msg = $wgContLang->lc( $this->getName() ) . '-summary';
 588                 } else {
 589                         $msg = $summaryMessageKey;
 590                 }
 591                 if ( !$this->msg( $msg )->isDisabled() && !$this->including() ) {
 592                         $this->getOutput()->wrapWikiMsg(
 593                                 "<div class='mw-specialpage-summary'>\n$1\n</div>", $msg );
 594                 }
 595         }
 596
 597         /**
 598          * Returns the name that goes in the \<h1\> in the special page itself, and
 599          * also the name that will be listed in Special:Specialpages
 600          *
 601          * Derived classes can override this, but usually it is easier to keep the
 602          * default behavior.
 603          *
 604          * @return string
 605          */
 606         function getDescription() {
 607                 return $this->msg( strtolower( $this->mName ) )->text();
 608         }
 609
 610         /**
 611          * Get a self-referential title object
 612          *
 613          * @param string|bool $subpage
 614          * @return Title
 615          * @deprecated since 1.23, use SpecialPage::getPageTitle
 616          */
 617         function getTitle( $subpage = false ) {
 618                 return $this->getPageTitle( $subpage );
 619         }
 620
 621         /**
 622          * Get a self-referential title object
 623          *
 624          * @param string|bool $subpage
 625          * @return Title
 626          * @since 1.23
 627          */
 628         function getPageTitle( $subpage = false ) {
 629                 return self::getTitleFor( $this->mName, $subpage );
 630         }
 631
 632         /**
 633          * Sets the context this SpecialPage is executed in
 634          *
 635          * @param IContextSource $context
 636          * @since 1.18
 637          */
 638         public function setContext( $context ) {
 639                 $this->mContext = $context;
 640         }
 641
 642         /**
 643          * Gets the context this SpecialPage is executed in
 644          *
 645          * @return IContextSource|RequestContext
 646          * @since 1.18
 647          */
 648         public function getContext() {
 649                 if ( $this->mContext instanceof IContextSource ) {
 650                         return $this->mContext;
 651                 } else {
 652                         wfDebug( __METHOD__ . " called and \$mContext is null. " .
 653                                 "Return RequestContext::getMain(); for sanity\n" );
 654
 655                         return RequestContext::getMain();
 656                 }
 657         }
 658
 659         /**
 660          * Get the WebRequest being used for this instance
 661          *
 662          * @return WebRequest
 663          * @since 1.18
 664          */
 665         public function getRequest() {
 666                 return $this->getContext()->getRequest();
 667         }
 668
 669         /**
 670          * Get the OutputPage being used for this instance
 671          *
 672          * @return OutputPage
 673          * @since 1.18
 674          */
 675         public function getOutput() {
 676                 return $this->getContext()->getOutput();
 677         }
 678
 679         /**
 680          * Shortcut to get the User executing this instance
 681          *
 682          * @return User
 683          * @since 1.18
 684          */
 685         public function getUser() {
 686                 return $this->getContext()->getUser();
 687         }
 688
 689         /**
 690          * Shortcut to get the skin being used for this instance
 691          *
 692          * @return Skin
 693          * @since 1.18
 694          */
 695         public function getSkin() {
 696                 return $this->getContext()->getSkin();
 697         }
 698
 699         /**
 700          * Shortcut to get user's language
 701          *
 702          * @return Language
 703          * @since 1.19
 704          */
 705         public function getLanguage() {
 706                 return $this->getContext()->getLanguage();
 707         }
 708
 709         /**
 710          * Shortcut to get main config object
 711          * @return Config
 712          * @since 1.24
 713          */
 714         public function getConfig() {
 715                 return $this->getContext()->getConfig();
 716         }
 717
 718         /**
 719          * Return the full title, including $par
 720          *
 721          * @return Title
 722          * @since 1.18
 723          */
 724         public function getFullTitle() {
 725                 return $this->getContext()->getTitle();
 726         }
 727
 728         /**
 729          * Return the robot policy. Derived classes that override this can change
 730          * the robot policy set by setHeaders() from the default 'noindex,nofollow'.
 731          *
 732          * @return string
 733          * @since 1.23
 734          */
 735         protected function getRobotPolicy() {
 736                 return 'noindex,nofollow';
 737         }
 738
 739         /**
 740          * Wrapper around wfMessage that sets the current context.
 741          *
 742          * @since 1.16
 743          * @return Message
 744          * @see wfMessage
 745          */
 746         public function msg( $key /* $args */ ) {
 747                 $message = call_user_func_array(
 748                         [ $this->getContext(), 'msg' ],
 749                         func_get_args()
 750                 );
 751                 // RequestContext passes context to wfMessage, and the language is set from
 752                 // the context, but setting the language for Message class removes the
 753                 // interface message status, which breaks for example usernameless gender
 754                 // invocations. Restore the flag when not including special page in content.
 755                 if ( $this->including() ) {
 756                         $message->setInterfaceMessageFlag( false );
 757                 }
 758
 759                 return $message;
 760         }
 761
 762         /**
 763          * Adds RSS/atom links
 764          *
 765          * @param array $params
 766          */
 767         protected function addFeedLinks( $params ) {
 768                 $feedTemplate = wfScript( 'api' );
 769
 770                 foreach ( $this->getConfig()->get( 'FeedClasses' ) as $format => $class ) {
 771                         $theseParams = $params + [ 'feedformat' => $format ];
 772                         $url = wfAppendQuery( $feedTemplate, $theseParams );
 773                         $this->getOutput()->addFeedLink( $format, $url );
 774                 }
 775         }
 776
 777         /**
 778          * Adds help link with an icon via page indicators.
 779          * Link target can be overridden by a local message containing a wikilink:
 780          * the message key is: lowercase special page name + '-helppage'.
 781          * @param string $to Target MediaWiki.org page title or encoded URL.
 782          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
 783          * @since 1.25
 784          */
 785         public function addHelpLink( $to, $overrideBaseUrl = false ) {
 786                 if ( $this->including() ) {
 787                         return;
 788                 }
 789
 790                 global $wgContLang;
 791                 $msg = $this->msg( $wgContLang->lc( $this->getName() ) . '-helppage' );
 792
 793                 if ( !$msg->isDisabled() ) {
 794                         $helpUrl = Skin::makeUrl( $msg->plain() );
 795                         $this->getOutput()->addHelpLink( $helpUrl, true );
 796                 } else {
 797                         $this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
 798                 }
 799         }
 800
 801         /**
 802          * Get the group that the special page belongs in on Special:SpecialPage
 803          * Use this method, instead of getGroupName to allow customization
 804          * of the group name from the wiki side
 805          *
 806          * @return string Group of this special page
 807          * @since 1.21
 808          */
 809         public function getFinalGroupName() {
 810                 $name = $this->getName();
 811
 812                 // Allow overbidding the group from the wiki side
 813                 $msg = $this->msg( 'specialpages-specialpagegroup-' . strtolower( $name ) )->inContentLanguage();
 814                 if ( !$msg->isBlank() ) {
 815                         $group = $msg->text();
 816                 } else {
 817                         // Than use the group from this object
 818                         $group = $this->getGroupName();
 819                 }
 820
 821                 return $group;
 822         }
 823
 824         /**
 825          * Indicates whether this special page may perform database writes
 826          *
 827          * @return bool
 828          * @since 1.27
 829          */
 830         public function doesWrites() {
 831                 return false;
 832         }
 833
 834         /**
 835          * Under which header this special page is listed in Special:SpecialPages
 836          * See messages 'specialpages-group-*' for valid names
 837          * This method defaults to group 'other'
 838          *
 839          * @return string
 840          * @since 1.21
 841          */
 842         protected function getGroupName() {
 843                 return 'other';
 844         }
 845
 846         /**
 847          * Call wfTransactionalTimeLimit() if this request was POSTed
 848          * @since 1.26
 849          */
 850         protected function useTransactionalTimeLimit() {
 851                 if ( $this->getRequest()->wasPosted() ) {
 852                         wfTransactionalTimeLimit();
 853                 }
 854         }
 855
 856         /**
 857          * @since 1.28
 858          * @return \MediaWiki\Linker\LinkRenderer
 859          */
 860         public function getLinkRenderer() {
 861                 if ( $this->linkRenderer ) {
 862                         return $this->linkRenderer;
 863                 } else {
 864                         return MediaWikiServices::getInstance()->getLinkRenderer();
 865                 }
 866         }
 867
 868         /**
 869          * @since 1.28
 870          * @param \MediaWiki\Linker\LinkRenderer $linkRenderer
 871          */
 872         public function setLinkRenderer( LinkRenderer $linkRenderer ) {
 873                 $this->linkRenderer = $linkRenderer;
 874         }
 875 }