Localisation updates from https://translatewiki.net.

[mediawiki.git] / includes / specialpage / SpecialPage.php

<?php
/**
 * Parent class for all special pages.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup SpecialPage
 */

namespace MediaWiki\SpecialPage;

use ErrorPageError;
use MediaWiki\Auth\AuthManager;
use MediaWiki\Config\Config;
use MediaWiki\Context\IContextSource;
use MediaWiki\Context\RequestContext;
use MediaWiki\HookContainer\HookContainer;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\Language\Language;
use MediaWiki\Language\RawMessage;
use MediaWiki\Linker\LinkRenderer;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Message\Message;
use MediaWiki\Navigation\PagerNavigationBuilder;
use MediaWiki\Output\OutputPage;
use MediaWiki\Permissions\Authority;
use MediaWiki\Permissions\PermissionStatus;
use MediaWiki\Request\WebRequest;
use MediaWiki\Title\Title;
use MediaWiki\Title\TitleValue;
use MediaWiki\User\User;
use MessageLocalizer;
use MWCryptRand;
use PermissionsError;
use ReadOnlyError;
use SearchEngineFactory;
use Skin;
use UserNotLoggedIn;
use Wikimedia\Message\MessageParam;
use Wikimedia\Message\MessageSpecifier;

/**
 * Parent class for all special pages.
 *
 * Includes some static functions for handling the special page list deprecated
 * in favor of SpecialPageFactory.
 *
 * @stable to extend
 *
 * @ingroup SpecialPage
 */
class SpecialPage implements MessageLocalizer {
        /**
         * @var string The canonical name of this special page
         * Also used as the message key for the default <h1> heading,
         * @see getDescription()
         */
        protected $mName;

        /** @var string The local name of this special page */
        private $mLocalName;

        /**
         * @var string Minimum user level required to access this page, or "" for anyone.
         * Also used to categorise the pages in Special:Specialpages
         */
        protected $mRestriction;

        /** @var bool Listed in Special:Specialpages? */
        private $mListed;

        /** @var bool Whether or not this special page is being included from an article */
        protected $mIncluding;

        /** @var bool Whether the special page can be included in an article */
        protected $mIncludable;

        /**
         * Current request context
         * @var IContextSource
         */
        protected $mContext;

        /** @var Language|null */
        private $contentLanguage;

        /**
         * @var LinkRenderer|null
         */
        private $linkRenderer = null;

        /** @var HookContainer|null */
        private $hookContainer;
        /** @var HookRunner|null */
        private $hookRunner;

        /** @var AuthManager|null */
        private $authManager = null;

        /** @var SpecialPageFactory */
        private $specialPageFactory;

        /**
         * Get the users preferred search page.
         *
         * It will fall back to Special:Search if the preference points to a page
         * that doesn't exist or is not defined.
         *
         * @since 1.38
         * @param User $user Search page can be customized by user preference.
         * @return Title
         */
        public static function newSearchPage( User $user ) {
                // Try user preference first
                $userOptionsManager = MediaWikiServices::getInstance()->getUserOptionsManager();
                $title = $userOptionsManager->getOption( $user, 'search-special-page' );
                if ( $title ) {
                        $page = self::getTitleFor( $title );
                        $factory = MediaWikiServices::getInstance()->getSpecialPageFactory();
                        if ( $factory->exists( $page->getText() ) ) {
                                return $page;
                        }
                }
                return self::getTitleFor( 'Search' );
        }

        /**
         * Get a localised Title object for a specified special page name
         * If you don't need a full Title object, consider using TitleValue through
         * getTitleValueFor() below.
         *
         * @since 1.9
         * @since 1.21 $fragment parameter added
         *
         * @param string $name
         * @param string|false|null $subpage Subpage string, or false/null to not use a subpage
         * @param string $fragment The link fragment (after the "#")
         * @return Title
         */
        public static function getTitleFor( $name, $subpage = false, $fragment = '' ) {
                return Title::newFromLinkTarget(
                        self::getTitleValueFor( $name, $subpage, $fragment )
                );
        }

        /**
         * Get a localised TitleValue object for a specified special page name
         *
         * @since 1.28
         * @param string $name
         * @param string|false|null $subpage Subpage string, or false/null to not use a subpage
         * @param string $fragment The link fragment (after the "#")
         * @return TitleValue
         */
        public static function getTitleValueFor( $name, $subpage = false, $fragment = '' ) {
                $name = MediaWikiServices::getInstance()->getSpecialPageFactory()->
                        getLocalNameFor( $name, $subpage );

                return new TitleValue( NS_SPECIAL, $name, $fragment );
        }

        /**
         * Get a localised Title object for a page name with a possibly unvalidated subpage
         *
         * @param string $name
         * @param string|false $subpage Subpage string, or false to not use a subpage
         * @return Title|null Title object or null if the page doesn't exist
         */
        public static function getSafeTitleFor( $name, $subpage = false ) {
                $name = MediaWikiServices::getInstance()->getSpecialPageFactory()->
                        getLocalNameFor( $name, $subpage );
                if ( $name ) {
                        return Title::makeTitleSafe( NS_SPECIAL, $name );
                } else {
                        return null;
                }
        }

        /**
         * Default constructor for special pages
         * Derivative classes should call this from their constructor
         *     Note that if the user does not have the required level, an error message will
         *     be displayed by the default execute() method, without the global function ever
         *     being called.
         *
         *     If you override execute(), you can recover the default behavior with userCanExecute()
         *     and displayRestrictionError()
         *
         * @stable to call
         *
         * @param string $name Name of the special page, as seen in links and URLs
         * @param string $restriction User right required, e.g. "block" or "delete"
         * @param bool $listed Whether the page is listed in Special:Specialpages
         * @param callable|bool $function Unused
         * @param string $file Unused
         * @param bool $includable Whether the page can be included in normal pages
         */
        public function __construct(
                $name = '', $restriction = '', $listed = true,
                $function = false, $file = '', $includable = false
        ) {
                $this->mName = $name;
                $this->mRestriction = $restriction;
                $this->mListed = $listed;
                $this->mIncludable = $includable;
        }

        /**
         * Get the canonical, unlocalized name of this special page without namespace.
         * @return string
         */
        public function getName() {
                return $this->mName;
        }

        /**
         * Get the permission that a user must have to execute this page
         * @return string
         */
        public function getRestriction() {
                return $this->mRestriction;
        }

        // @todo FIXME: Decide which syntax to use for this, and stick to it

        /**
         * Whether this special page is listed in Special:SpecialPages
         * @stable to override
         * @since 1.3 (r3583)
         * @return bool
         */
        public function isListed() {
                return $this->mListed;
        }

        /**
         * Whether it's allowed to transclude the special page via {{Special:Foo/params}}
         * @stable to override
         * @return bool
         */
        public function isIncludable() {
                return $this->mIncludable;
        }

        /**
         * How long to cache page when it is being included.
         *
         * @note If cache time is not 0, then the current user becomes an anon
         *   if you want to do any per-user customizations, than this method
         *   must be overridden to return 0.
         * @since 1.26
         * @stable to override
         * @return int Time in seconds, 0 to disable caching altogether,
         *  false to use the parent page's cache settings
         */
        public function maxIncludeCacheTime() {
                return $this->getConfig()->get( MainConfigNames::MiserMode ) ? $this->getCacheTTL() : 0;
        }

        /**
         * @stable to override
         * @return int Seconds that this page can be cached
         */
        protected function getCacheTTL() {
                return 60 * 60;
        }

        /**
         * Whether the special page is being evaluated via transclusion
         * @param bool|null $x
         * @return bool
         */
        public function including( $x = null ) {
                return wfSetVar( $this->mIncluding, $x );
        }

        /**
         * Get the localised name of the special page
         * @stable to override
         * @return string
         */
        public function getLocalName() {
                if ( $this->mLocalName === null ) {
                        $this->mLocalName = $this->getSpecialPageFactory()->getLocalNameFor( $this->mName );
                }

                return $this->mLocalName;
        }

        /**
         * Is this page expensive (for some definition of expensive)?
         * Expensive pages are disabled or cached in miser mode.  Originally used
         * (and still overridden) by QueryPage and subclasses, moved here so that
         * Special:SpecialPages can safely call it for all special pages.
         *
         * @stable to override
         * @return bool
         */
        public function isExpensive() {
                return false;
        }

        /**
         * Is this page cached?
         * Expensive pages are cached or disabled in miser mode.
         * Used by QueryPage and subclasses, moved here so that
         * Special:SpecialPages can safely call it for all special pages.
         *
         * @stable to override
         * @return bool
         * @since 1.21
         */
        public function isCached() {
                return false;
        }

        /**
         * Can be overridden by subclasses with more complicated permissions
         * schemes.
         *
         * @stable to override
         * @return bool Should the page be displayed with the restricted-access
         *   pages?
         */
        public function isRestricted() {
                // DWIM: If anons can do something, then it is not restricted
                return $this->mRestriction != '' && !MediaWikiServices::getInstance()
                        ->getGroupPermissionsLookup()
                        ->groupHasPermission( '*', $this->mRestriction );
        }

        /**
         * Checks if the given user (identified by an object) can execute this
         * special page (as defined by $mRestriction).  Can be overridden by sub-
         * classes with more complicated permissions schemes.
         *
         * @stable to override
         * @param User $user The user to check
         * @return bool Does the user have permission to view the page?
         */
        public function userCanExecute( User $user ) {
                return MediaWikiServices::getInstance()
                        ->getPermissionManager()
                        ->userHasRight( $user, $this->mRestriction );
        }

        /**
         * Utility function for authorizing an action to be performed by the special
         * page. User blocks and rate limits are enforced implicitly.
         *
         * @see Authority::authorizeAction.
         *
         * @param ?string $action If not given, the action returned by
         *        getRestriction() will be used.
         *
         * @return PermissionStatus
         */
        protected function authorizeAction( ?string $action = null ): PermissionStatus {
                $action ??= $this->getRestriction();

                if ( !$action ) {
                        return PermissionStatus::newGood();
                }

                $status = PermissionStatus::newEmpty();
                $this->getAuthority()->authorizeAction( $action, $status );
                return $status;
        }

        /**
         * Output an error message telling the user what access level they have to have
         * @stable to override
         * @throws PermissionsError
         * @return never
         */
        protected function displayRestrictionError() {
                throw new PermissionsError( $this->mRestriction );
        }

        /**
         * Checks if userCanExecute, and if not throws a PermissionsError
         *
         * @stable to override
         * @since 1.19
         * @return void
         * @throws PermissionsError
         */
        public function checkPermissions() {
                if ( !$this->userCanExecute( $this->getUser() ) ) {
                        $this->displayRestrictionError();
                }
        }

        /**
         * If the wiki is currently in readonly mode, throws a ReadOnlyError
         *
         * @since 1.19
         * @return void
         * @throws ReadOnlyError
         */
        public function checkReadOnly() {
                // Can not inject the ReadOnlyMode as it would break the installer since
                // it instantiates SpecialPageFactory before the DB (via ParserFactory for message parsing)
                if ( MediaWikiServices::getInstance()->getReadOnlyMode()->isReadOnly() ) {
                        throw new ReadOnlyError;
                }
        }

        /**
         * If the user is not logged in, throws UserNotLoggedIn error
         *
         * The user will be redirected to Special:Userlogin with the given message as an error on
         * the form.
         *
         * @since 1.23
         * @param string $reasonMsg [optional] Message key to be displayed on login page
         * @param string $titleMsg [optional] Passed on to UserNotLoggedIn constructor
         * @throws UserNotLoggedIn
         */
        public function requireLogin(
                $reasonMsg = 'exception-nologin-text', $titleMsg = 'exception-nologin'
        ) {
                if ( $this->getUser()->isAnon() ) {
                        throw new UserNotLoggedIn( $reasonMsg, $titleMsg );
                }
        }

        /**
         * If the user is not logged in or is a temporary user, throws UserNotLoggedIn
         *
         * @since 1.39
         * @param string $reasonMsg [optional] Message key to be displayed on login page
         * @param string $titleMsg [optional] Passed on to UserNotLoggedIn constructor. Default 'exception-nologin'
         *    which is used when $titleMsg is null.
         * @param bool $alwaysRedirectToLoginPage [optional] Should the redirect always go to Special:UserLogin?
         *    If false (the default), the redirect will be to Special:CreateAccount when the user is logged in to
         *    a temporary account.
         * @throws UserNotLoggedIn
         */
        public function requireNamedUser(
                $reasonMsg = 'exception-nologin-text', $titleMsg = 'exception-nologin', bool $alwaysRedirectToLoginPage = false
        ) {
                if ( !$this->getUser()->isNamed() ) {
                        throw new UserNotLoggedIn( $reasonMsg, $titleMsg, [], $alwaysRedirectToLoginPage );
                }
        }

        /**
         * Tells if the special page does something security-sensitive and needs extra defense against
         * a stolen account (e.g. a reauthentication). What exactly that will mean is decided by the
         * authentication framework.
         * @stable to override
         * @return string|false False or the argument for AuthManager::securitySensitiveOperationStatus().
         *   Typically a special page needing elevated security would return its name here.
         */
        protected function getLoginSecurityLevel() {
                return false;
        }

        /**
         * Record preserved POST data after a reauthentication.
         *
         * This is called from checkLoginSecurityLevel() when returning from the
         * redirect for reauthentication, if the redirect had been served in
         * response to a POST request.
         *
         * The base SpecialPage implementation does nothing. If your subclass uses
         * getLoginSecurityLevel() or checkLoginSecurityLevel(), it should probably
         * implement this to do something with the data.
         *
         * @note Call self::setAuthManager from special page constructor when overriding
         *
         * @stable to override
         * @since 1.32
         * @param array $data
         */
        protected function setReauthPostData( array $data ) {
        }

        /**
         * Verifies that the user meets the security level, possibly reauthenticating them in the process.
         *
         * This should be used when the page does something security-sensitive and needs extra defense
         * against a stolen account (e.g. a reauthentication). The authentication framework will make
         * an extra effort to make sure the user account is not compromised. What that exactly means
         * will depend on the system and user settings; e.g. the user might be required to log in again
         * unless their last login happened recently, or they might be given a second-factor challenge.
         *
         * Calling this method will result in one if these actions:
         * - return true: all good.
         * - return false and set a redirect: caller should abort; the redirect will take the user
         *   to the login page for reauthentication, and back.
         * - throw an exception if there is no way for the user to meet the requirements without using
         *   a different access method (e.g. this functionality is only available from a specific IP).
         *
         * Note that this does not in any way check that the user is authorized to use this special page
         * (use checkPermissions() for that).
         *
         * @param string|null $level A security level. Can be an arbitrary string, defaults to the page
         *   name.
         * @return bool False means a redirect to the reauthentication page has been set and processing
         *   of the special page should be aborted.
         * @throws ErrorPageError If the security level cannot be met, even with reauthentication.
         */
        protected function checkLoginSecurityLevel( $level = null ) {
                $level = $level ?: $this->getName();
                $key = 'SpecialPage:reauth:' . $this->getName();
                $request = $this->getRequest();

                $securityStatus = $this->getAuthManager()->securitySensitiveOperationStatus( $level );
                if ( $securityStatus === AuthManager::SEC_OK ) {
                        $uniqueId = $request->getVal( 'postUniqueId' );
                        if ( $uniqueId ) {
                                $key .= ':' . $uniqueId;
                                $session = $request->getSession();
                                $data = $session->getSecret( $key );
                                if ( $data ) {
                                        $session->remove( $key );
                                        $this->setReauthPostData( $data );
                                }
                        }
                        return true;
                } elseif ( $securityStatus === AuthManager::SEC_REAUTH ) {
                        $title = self::getTitleFor( 'Userlogin' );
                        $queryParams = $request->getQueryValues();

                        if ( $request->wasPosted() ) {
                                $data = array_diff_assoc( $request->getValues(), $request->getQueryValues() );
                                if ( $data ) {
                                        // unique ID in case the same special page is open in multiple browser tabs
                                        $uniqueId = MWCryptRand::generateHex( 6 );
                                        $key .= ':' . $uniqueId;
                                        $queryParams['postUniqueId'] = $uniqueId;
                                        $session = $request->getSession();
                                        $session->persist(); // Just in case
                                        $session->setSecret( $key, $data );
                                }
                        }

                        $query = [
                                'returnto' => $this->getFullTitle()->getPrefixedDBkey(),
                                'returntoquery' => wfArrayToCgi( array_diff_key( $queryParams, [ 'title' => true ] ) ),
                                'force' => $level,
                        ];
                        $url = $title->getFullURL( $query, false, PROTO_HTTPS );

                        $this->getOutput()->redirect( $url );
                        return false;
                }

                $titleMessage = wfMessage( 'specialpage-securitylevel-not-allowed-title' );
                $errorMessage = wfMessage( 'specialpage-securitylevel-not-allowed' );
                throw new ErrorPageError( $titleMessage, $errorMessage );
        }

        /**
         * Set the injected AuthManager from the special page constructor
         *
         * @since 1.36
         * @param AuthManager $authManager
         */
        final protected function setAuthManager( AuthManager $authManager ) {
                $this->authManager = $authManager;
        }

        /**
         * @note Call self::setAuthManager from special page constructor when using
         *
         * @since 1.36
         * @return AuthManager
         */
        final protected function getAuthManager(): AuthManager {
                if ( $this->authManager === null ) {
                        // Fallback if not provided
                        // TODO Change to wfWarn in a future release
                        $this->authManager = MediaWikiServices::getInstance()->getAuthManager();
                }
                return $this->authManager;
        }

        /**
         * Return an array of subpages beginning with $search that this special page will accept.
         *
         * For example, if a page supports subpages "foo", "bar" and "baz" (as in Special:PageName/foo,
         * etc.):
         *
         *   - `prefixSearchSubpages( "ba" )` should return `[ "bar", "baz" ]`
         *   - `prefixSearchSubpages( "f" )` should return `[ "foo" ]`
         *   - `prefixSearchSubpages( "z" )` should return `[]`
         *   - `prefixSearchSubpages( "" )` should return `[ foo", "bar", "baz" ]`
         *
         * @stable to override
         * @param string $search Prefix to search for
         * @param int $limit Maximum number of results to return (usually 10)
         * @param int $offset Number of results to skip (usually 0)
         * @return string[] Matching subpages
         */
        public function prefixSearchSubpages( $search, $limit, $offset ) {
                $subpages = $this->getSubpagesForPrefixSearch();
                if ( !$subpages ) {
                        return [];
                }

                return self::prefixSearchArray( $search, $limit, $subpages, $offset );
        }

        /**
         * Return an array of subpages that this special page will accept for prefix
         * searches. If this method requires a query you might instead want to implement
         * prefixSearchSubpages() directly so you can support $limit and $offset. This
         * method is better for static-ish lists of things.
         *
         * @stable to override
         * @return string[] subpages to search from
         */
        protected function getSubpagesForPrefixSearch() {
                return [];
        }

        /**
         * Return an array of strings representing page titles that are discoverable to end users via UI.
         *
         * @since 1.39
         * @stable to call or override
         * @return string[] strings representing page titles that can be rendered by skins if required.
         */
        public function getAssociatedNavigationLinks() {
                return [];
        }

        /**
         * Perform a regular substring search for prefixSearchSubpages
         * @since 1.36 Added $searchEngineFactory parameter
         * @param string $search Prefix to search for
         * @param int $limit Maximum number of results to return (usually 10)
         * @param int $offset Number of results to skip (usually 0)
         * @param SearchEngineFactory|null $searchEngineFactory Provide the service
         * @return string[] Matching subpages
         */
        protected function prefixSearchString(
                $search,
                $limit,
                $offset,
                ?SearchEngineFactory $searchEngineFactory = null
        ) {
                $title = Title::newFromText( $search );
                if ( !$title || !$title->canExist() ) {
                        // No prefix suggestion in special and media namespace
                        return [];
                }

                $searchEngine = $searchEngineFactory
                        ? $searchEngineFactory->create()
                        // Fallback if not provided
                        // TODO Change to wfWarn in a future release
                        : MediaWikiServices::getInstance()->newSearchEngine();
                $searchEngine->setLimitOffset( $limit, $offset );
                $searchEngine->setNamespaces( [] );
                $result = $searchEngine->defaultPrefixSearch( $search );
                return array_map( static function ( Title $t ) {
                        return $t->getPrefixedText();
                }, $result );
        }

        /**
         * Helper function for implementations of prefixSearchSubpages() that
         * filter the values in memory (as opposed to making a query).
         *
         * @since 1.24
         * @param string $search
         * @param int $limit
         * @param array $subpages
         * @param int $offset
         * @return string[]
         */
        protected static function prefixSearchArray( $search, $limit, array $subpages, $offset ) {
                $escaped = preg_quote( $search, '/' );
                return array_slice( preg_grep( "/^$escaped/i",
                        array_slice( $subpages, $offset ) ), 0, $limit );
        }

        /**
         * Sets headers - this should be called from the execute() method of all derived classes!
         * @stable to override
         */
        protected function setHeaders() {
                $out = $this->getOutput();
                $out->setArticleRelated( false );
                $out->setRobotPolicy( $this->getRobotPolicy() );
                $title = $this->getDescription();
                // T343849
                if ( is_string( $title ) ) {
                        wfDeprecated( "string return from {$this->getName()}::getDescription()", '1.41' );
                        $title = ( new RawMessage( '$1' ) )->rawParams( $title );
                }
                $out->setPageTitleMsg( $title );
        }

        /**
         * Entry point.
         *
         * @since 1.20
         *
         * @param string|null $subPage
         */
        final public function run( $subPage ) {
                if ( !$this->getHookRunner()->onSpecialPageBeforeExecute( $this, $subPage ) ) {
                        return;
                }

                if ( $this->beforeExecute( $subPage ) === false ) {
                        return;
                }
                $this->execute( $subPage );
                $this->afterExecute( $subPage );

                $this->getHookRunner()->onSpecialPageAfterExecute( $this, $subPage );
        }

        /**
         * Gets called before @see SpecialPage::execute.
         * Return false to prevent calling execute() (since 1.27+).
         *
         * @stable to override
         * @since 1.20
         *
         * @param string|null $subPage
         * @return bool|void
         */
        protected function beforeExecute( $subPage ) {
                // No-op
        }

        /**
         * Gets called after @see SpecialPage::execute.
         *
         * @stable to override
         * @since 1.20
         *
         * @param string|null $subPage
         */
        protected function afterExecute( $subPage ) {
                // No-op
        }

        /**
         * Default execute method
         * Checks user permissions
         *
         * This must be overridden by subclasses; it will be made abstract in a future version
         *
         * @stable to override
         *
         * @param string|null $subPage
         */
        public function execute( $subPage ) {
                $this->setHeaders();
                $this->checkPermissions();
                $securityLevel = $this->getLoginSecurityLevel();
                if ( $securityLevel !== false && !$this->checkLoginSecurityLevel( $securityLevel ) ) {
                        return;
                }
                $this->outputHeader();
        }

        /**
         * Outputs a summary message on top of special pages
         * By default the message key is the canonical name of the special page
         * May be overridden, i.e. by extensions to stick with the naming conventions
         * for message keys: 'extensionname-xxx'
         *
         * @stable to override
         *
         * @param string $summaryMessageKey Message key of the summary
         */
        protected function outputHeader( $summaryMessageKey = '' ) {
                if ( $summaryMessageKey == '' ) {
                        $msg = strtolower( $this->getName() ) . '-summary';
                } else {
                        $msg = $summaryMessageKey;
                }
                if ( !$this->msg( $msg )->isDisabled() && !$this->including() ) {
                        $this->getOutput()->wrapWikiMsg(
                                "<div class='mw-specialpage-summary'>\n$1\n</div>", $msg );
                }
        }

        /**
         * Returns the name that goes in the \<h1\> in the special page itself, and
         * also the name that will be listed in Special:Specialpages
         *
         * Derived classes can override this, but usually it is easier to keep the
         * default behavior.
         *
         * Returning a string from this method has been deprecated since 1.41.
         *
         * @stable to override
         *
         * @return string|Message
         */
        public function getDescription() {
                return $this->msg( strtolower( $this->mName ) );
        }

        /**
         * Similar to getDescription, but takes into account subpages and designed for display
         * in tabs.
         *
         * @since 1.39
         * @stable to override if special page has complex parameter handling. Use default message keys
         * where possible.
         *
         * @param string $path (optional)
         * @return string
         */
        public function getShortDescription( string $path = '' ): string {
                $lowerPath = strtolower( str_replace( '/', '-', $path ) );
                $shortKey = 'special-tab-' . $lowerPath;
                $shortKey .= '-short';
                $msgShort = $this->msg( $shortKey );
                return $msgShort->text();
        }

        /**
         * Get a self-referential title object
         *
         * @param string|false|null $subpage
         * @return Title
         * @since 1.23
         */
        public function getPageTitle( $subpage = false ) {
                return self::getTitleFor( $this->mName, $subpage );
        }

        /**
         * Sets the context this SpecialPage is executed in
         *
         * @param IContextSource $context
         * @since 1.18
         */
        public function setContext( $context ) {
                $this->mContext = $context;
        }

        /**
         * Gets the context this SpecialPage is executed in
         *
         * @return IContextSource|RequestContext
         * @since 1.18
         */
        public function getContext() {
                if ( !( $this->mContext instanceof IContextSource ) ) {
                        wfDebug( __METHOD__ . " called and \$mContext is null. " .
                                "Using RequestContext::getMain()" );

                        $this->mContext = RequestContext::getMain();
                }
                return $this->mContext;
        }

        /**
         * Get the WebRequest being used for this instance
         *
         * @return WebRequest
         * @since 1.18
         */
        public function getRequest() {
                return $this->getContext()->getRequest();
        }

        /**
         * Get the OutputPage being used for this instance
         *
         * @return OutputPage
         * @since 1.18
         */
        public function getOutput() {
                return $this->getContext()->getOutput();
        }

        /**
         * Shortcut to get the User executing this instance
         *
         * @return User
         * @since 1.18
         */
        public function getUser() {
                return $this->getContext()->getUser();
        }

        /**
         * Shortcut to get the Authority executing this instance
         *
         * @return Authority
         * @since 1.36
         */
        public function getAuthority(): Authority {
                return $this->getContext()->getAuthority();
        }

        /**
         * Shortcut to get the skin being used for this instance
         *
         * @return Skin
         * @since 1.18
         */
        public function getSkin() {
                return $this->getContext()->getSkin();
        }

        /**
         * Shortcut to get user's language
         *
         * @return Language
         * @since 1.19
         */
        public function getLanguage() {
                return $this->getContext()->getLanguage();
        }

        /**
         * Shortcut to get content language
         *
         * @return Language
         * @since 1.36
         */
        final public function getContentLanguage(): Language {
                if ( $this->contentLanguage === null ) {
                        // Fallback if not provided
                        // TODO Change to wfWarn in a future release
                        $this->contentLanguage = MediaWikiServices::getInstance()->getContentLanguage();
                }
                return $this->contentLanguage;
        }

        /**
         * Set content language
         *
         * @internal For factory only
         * @param Language $contentLanguage
         * @since 1.36
         */
        final public function setContentLanguage( Language $contentLanguage ) {
                $this->contentLanguage = $contentLanguage;
        }

        /**
         * Shortcut to get main config object
         * @return Config
         * @since 1.24
         */
        public function getConfig() {
                return $this->getContext()->getConfig();
        }

        /**
         * Return the full title, including $par
         *
         * @return Title
         * @since 1.18
         */
        public function getFullTitle() {
                return $this->getContext()->getTitle();
        }

        /**
         * Return the robot policy. Derived classes that override this can change
         * the robot policy set by setHeaders() from the default 'noindex,nofollow'.
         *
         * @return string
         * @since 1.23
         */
        protected function getRobotPolicy() {
                return 'noindex,nofollow';
        }

        /**
         * Wrapper around wfMessage that sets the current context.
         *
         * @since 1.16
         * @param string|string[]|MessageSpecifier $key
         * @phpcs:ignore Generic.Files.LineLength
         * @param MessageParam|MessageSpecifier|string|int|float|list<MessageParam|MessageSpecifier|string|int|float> ...$params
         *   See Message::params()
         * @return Message
         * @see wfMessage
         */
        public function msg( $key, ...$params ) {
                $message = $this->getContext()->msg( $key, ...$params );
                // RequestContext passes context to wfMessage, and the language is set from
                // the context, but setting the language for Message class removes the
                // interface message status, which breaks for example usernameless gender
                // invocations. Restore the flag when not including special page in content.
                if ( $this->including() ) {
                        $message->setInterfaceMessageFlag( false );
                }

                return $message;
        }

        /**
         * Adds RSS/atom links
         *
         * @param array $params
         */
        protected function addFeedLinks( $params ) {
                $feedTemplate = wfScript( 'api' );

                foreach ( $this->getConfig()->get( MainConfigNames::FeedClasses ) as $format => $class ) {
                        $theseParams = $params + [ 'feedformat' => $format ];
                        $url = wfAppendQuery( $feedTemplate, $theseParams );
                        $this->getOutput()->addFeedLink( $format, $url );
                }
        }

        /**
         * Adds help link with an icon via page indicators.
         * Link target can be overridden by a local message containing a wikilink:
         * the message key is: lowercase special page name + '-helppage'.
         * @param string $to Target MediaWiki.org page title or encoded URL.
         * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
         * @since 1.25
         */
        public function addHelpLink( $to, $overrideBaseUrl = false ) {
                if ( $this->including() ) {
                        return;
                }

                $msg = $this->msg( strtolower( $this->getName() ) . '-helppage' );

                if ( !$msg->isDisabled() ) {
                        $title = Title::newFromText( $msg->plain() );
                        if ( $title instanceof Title ) {
                                $this->getOutput()->addHelpLink( $title->getLocalURL(), true );
                        }
                } else {
                        $this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
                }
        }

        /**
         * Get the group that the special page belongs in on Special:SpecialPage
         * Use this method, instead of getGroupName to allow customization
         * of the group name from the wiki side
         *
         * @return string Group of this special page
         * @since 1.21
         */
        public function getFinalGroupName() {
                $name = $this->getName();

                // Allow overriding the group from the wiki side
                $msg = $this->msg( 'specialpages-specialpagegroup-' . strtolower( $name ) )->inContentLanguage();
                if ( !$msg->isBlank() ) {
                        $group = $msg->text();
                } else {
                        // Than use the group from this object
                        $group = $this->getGroupName();
                }

                return $group;
        }

        /**
         * Indicates whether POST requests to this special page require write access to the wiki.
         *
         * Subclasses must override this method to return true if any of the operations that
         * they perform on POST requests are not "safe" per RFC 7231 section 4.2.1. A subclass's
         * operation is "safe" if it is essentially read-only, i.e. the client does not request
         * nor expect any state change that would be observable in the responses to future requests.
         *
         * Implementations of this method must always return the same value, regardless of the
         * parameters passed to the constructor or system state.
         *
         * When handling GET/HEAD requests, subclasses should only perform "safe" operations.
         * Note that some subclasses might only perform "safe" operations even for POST requests,
         * particularly in the case where large input parameters are required.
         *
         * @stable to override
         *
         * @return bool
         * @since 1.27
         */
        public function doesWrites() {
                return false;
        }

        /**
         * Under which header this special page is listed in Special:SpecialPages
         * See messages 'specialpages-group-*' for valid names
         * This method defaults to group 'other'
         *
         * @stable to override
         *
         * @return string
         * @since 1.21
         */
        protected function getGroupName() {
                return 'other';
        }

        /**
         * Call wfTransactionalTimeLimit() if this request was POSTed
         * @since 1.26
         */
        protected function useTransactionalTimeLimit() {
                if ( $this->getRequest()->wasPosted() ) {
                        wfTransactionalTimeLimit();
                }
        }

        /**
         * @since 1.28
         * @return LinkRenderer
         */
        public function getLinkRenderer(): LinkRenderer {
                if ( $this->linkRenderer === null ) {
                        // TODO Inject the service
                        $this->linkRenderer = MediaWikiServices::getInstance()->getLinkRendererFactory()
                                ->create();
                }
                return $this->linkRenderer;
        }

        /**
         * @since 1.28
         * @param LinkRenderer $linkRenderer
         */
        public function setLinkRenderer( LinkRenderer $linkRenderer ) {
                $this->linkRenderer = $linkRenderer;
        }

        /**
         * Generate (prev x| next x) (20|50|100...) type links for paging
         *
         * @param int $offset
         * @param int $limit
         * @param array $query Optional URL query parameter string
         * @param bool $atend Optional param for specified if this is the last page
         * @param string|false $subpage Optional param for specifying subpage
         * @return string
         */
        protected function buildPrevNextNavigation(
                $offset,
                $limit,
                array $query = [],
                $atend = false,
                $subpage = false
        ) {
                $navBuilder = new PagerNavigationBuilder( $this );
                $navBuilder
                        ->setPage( $this->getPageTitle( $subpage ) )
                        ->setLinkQuery( [ 'limit' => $limit, 'offset' => $offset ] + $query )
                        ->setLimitLinkQueryParam( 'limit' )
                        ->setCurrentLimit( $limit )
                        ->setPrevTooltipMsg( 'prevn-title' )
                        ->setNextTooltipMsg( 'nextn-title' )
                        ->setLimitTooltipMsg( 'shown-title' );

                if ( $offset > 0 ) {
                        $navBuilder->setPrevLinkQuery( [ 'offset' => (string)max( $offset - $limit, 0 ) ] );
                }
                if ( !$atend ) {
                        $navBuilder->setNextLinkQuery( [ 'offset' => (string)( $offset + $limit ) ] );
                }

                return $navBuilder->getHtml();
        }

        /**
         * @since 1.35
         * @internal
         * @param HookContainer $hookContainer
         */
        public function setHookContainer( HookContainer $hookContainer ) {
                $this->hookContainer = $hookContainer;
                $this->hookRunner = new HookRunner( $hookContainer );
        }

        /**
         * @since 1.35
         * @return HookContainer
         */
        protected function getHookContainer() {
                if ( !$this->hookContainer ) {
                        $this->hookContainer = MediaWikiServices::getInstance()->getHookContainer();
                }
                return $this->hookContainer;
        }

        /**
         * @internal This is for use by core only. Hook interfaces may be removed
         *   without notice.
         * @since 1.35
         * @return HookRunner
         */
        protected function getHookRunner() {
                if ( !$this->hookRunner ) {
                        $this->hookRunner = new HookRunner( $this->getHookContainer() );
                }
                return $this->hookRunner;
        }

        /**
         * @internal For factory only
         * @since 1.36
         * @param SpecialPageFactory $specialPageFactory
         */
        final public function setSpecialPageFactory( SpecialPageFactory $specialPageFactory ) {
                $this->specialPageFactory = $specialPageFactory;
        }

        /**
         * @since 1.36
         * @return SpecialPageFactory
         */
        final protected function getSpecialPageFactory(): SpecialPageFactory {
                if ( !$this->specialPageFactory ) {
                        // Fallback if not provided
                        // TODO Change to wfWarn in a future release
                        $this->specialPageFactory = MediaWikiServices::getInstance()->getSpecialPageFactory();
                }
                return $this->specialPageFactory;
        }
}

/** @deprecated class alias since 1.41 */
class_alias( SpecialPage::class, 'SpecialPage' );