PHPSessionHandler: Implement SessionHandlerInterface

[mediawiki.git] / includes / skins / Skin.php

<?php
/**
 * Base class for all skins.
 *
 * 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
 */

/**
 * @defgroup Skins Skins
 */

/**
 * The main skin class which provides methods and properties for all other skins.
 *
 * See docs/skin.txt for more information.
 *
 * @ingroup Skins
 */
abstract class Skin extends ContextSource {
        protected $skinname = null;
        protected $mRelevantTitle = null;
        protected $mRelevantUser = null;

        /**
         * @var string Stylesheets set to use. Subdirectory in skins/ where various stylesheets are
         *   located. Only needs to be set if you intend to use the getSkinStylePath() method.
         */
        public $stylename = null;

        /**
         * Fetch the set of available skins.
         * @return array Associative array of strings
         */
        static function getSkinNames() {
                return SkinFactory::getDefaultInstance()->getSkinNames();
        }

        /**
         * Fetch the skinname messages for available skins.
         * @return string[]
         */
        static function getSkinNameMessages() {
                $messages = array();
                foreach ( self::getSkinNames() as $skinKey => $skinName ) {
                        $messages[] = "skinname-$skinKey";
                }
                return $messages;
        }

        /**
         * Fetch the list of user-selectable skins in regards to $wgSkipSkins.
         * Useful for Special:Preferences and other places where you
         * only want to show skins users _can_ use.
         * @return string[]
         * @since 1.23
         */
        public static function getAllowedSkins() {
                global $wgSkipSkins;

                $allowedSkins = self::getSkinNames();

                foreach ( $wgSkipSkins as $skip ) {
                        unset( $allowedSkins[$skip] );
                }

                return $allowedSkins;
        }

        /**
         * @deprecated since 1.23, use getAllowedSkins
         * @return string[]
         */
        public static function getUsableSkins() {
                wfDeprecated( __METHOD__, '1.23' );
                return self::getAllowedSkins();
        }

        /**
         * Normalize a skin preference value to a form that can be loaded.
         *
         * If a skin can't be found, it will fall back to the configured default ($wgDefaultSkin), or the
         * hardcoded default ($wgFallbackSkin) if the default skin is unavailable too.
         *
         * @param string $key 'monobook', 'vector', etc.
         * @return string
         */
        static function normalizeKey( $key ) {
                global $wgDefaultSkin, $wgFallbackSkin;

                $skinNames = Skin::getSkinNames();

                // Make keys lowercase for case-insensitive matching.
                $skinNames = array_change_key_case( $skinNames, CASE_LOWER );
                $key = strtolower( $key );
                $defaultSkin = strtolower( $wgDefaultSkin );
                $fallbackSkin = strtolower( $wgFallbackSkin );

                if ( $key == '' || $key == 'default' ) {
                        // Don't return the default immediately;
                        // in a misconfiguration we need to fall back.
                        $key = $defaultSkin;
                }

                if ( isset( $skinNames[$key] ) ) {
                        return $key;
                }

                // Older versions of the software used a numeric setting
                // in the user preferences.
                $fallback = array(
                        0 => $defaultSkin,
                        2 => 'cologneblue'
                );

                if ( isset( $fallback[$key] ) ) {
                        $key = $fallback[$key];
                }

                if ( isset( $skinNames[$key] ) ) {
                        return $key;
                } elseif ( isset( $skinNames[$defaultSkin] ) ) {
                        return $defaultSkin;
                } else {
                        return $fallbackSkin;
                }
        }

        /**
         * Factory method for loading a skin of a given type
         * @param string $key 'monobook', 'vector', etc.
         * @return Skin
         * @deprecated since 1.24; Use SkinFactory instead
         */
        static function &newFromKey( $key ) {
                wfDeprecated( __METHOD__, '1.24' );

                $key = Skin::normalizeKey( $key );
                $factory = SkinFactory::getDefaultInstance();

                // normalizeKey() guarantees that a skin with this key will exist.
                $skin = $factory->makeSkin( $key );
                return $skin;
        }

        /**
         * @return string Skin name
         */
        public function getSkinName() {
                return $this->skinname;
        }

        /**
         * @param OutputPage $out
         */
        function initPage( OutputPage $out ) {

                $this->preloadExistence();

        }

        /**
         * Defines the ResourceLoader modules that should be added to the skin
         * It is recommended that skins wishing to override call parent::getDefaultModules()
         * and substitute out any modules they wish to change by using a key to look them up
         * @return array Array of modules with helper keys for easy overriding
         */
        public function getDefaultModules() {
                global $wgUseAjax, $wgEnableAPI, $wgEnableWriteAPI;

                $out = $this->getOutput();
                $user = $out->getUser();
                $modules = array(
                        // modules that enhance the page content in some way
                        'content' => array(
                                'mediawiki.page.ready',
                        ),
                        // modules that exist for legacy reasons
                        'legacy' => ResourceLoaderStartUpModule::getLegacyModules(),
                        // modules relating to search functionality
                        'search' => array(),
                        // modules relating to functionality relating to watching an article
                        'watch' => array(),
                        // modules which relate to the current users preferences
                        'user' => array(),
                );

                // Add various resources if required
                if ( $wgUseAjax && $wgEnableAPI ) {
                        if ( $wgEnableWriteAPI && $user->isLoggedIn()
                                && $user->isAllowedAll( 'writeapi', 'viewmywatchlist', 'editmywatchlist' )
                                && $this->getRelevantTitle()->canExist()
                        ) {
                                $modules['watch'][] = 'mediawiki.page.watch.ajax';
                        }

                        $modules['search'][] = 'mediawiki.searchSuggest';
                }

                if ( $user->getBoolOption( 'editsectiononrightclick' ) ) {
                        $modules['user'][] = 'mediawiki.action.view.rightClickEdit';
                }

                // Crazy edit-on-double-click stuff
                if ( $out->isArticle() && $user->getOption( 'editondblclick' ) ) {
                        $modules['user'][] = 'mediawiki.action.view.dblClickEdit';
                }
                return $modules;
        }

        /**
         * Preload the existence of three commonly-requested pages in a single query
         */
        function preloadExistence() {
                $titles = array();

                $user = $this->getUser();
                $title = $this->getRelevantTitle();

                // User/talk link
                if ( $user->isLoggedIn() ) {
                        $titles[] = $user->getUserPage();
                        $titles[] = $user->getTalkPage();
                }

                // Check, if the page can hold some kind of content, otherwise do nothing
                if ( !$title->canExist() ) {
                        // nothing
                } elseif ( $title->isTalkPage() ) {
                        $titles[] = $title->getSubjectPage();
                } else {
                        $titles[] = $title->getTalkPage();
                }

                Hooks::run( 'SkinPreloadExistence', array( &$titles, $this ) );

                if ( count( $titles ) ) {
                        $lb = new LinkBatch( $titles );
                        $lb->setCaller( __METHOD__ );
                        $lb->execute();
                }
        }

        /**
         * Get the current revision ID
         *
         * @return int
         */
        public function getRevisionId() {
                return $this->getOutput()->getRevisionId();
        }

        /**
         * Whether the revision displayed is the latest revision of the page
         *
         * @return bool
         */
        public function isRevisionCurrent() {
                $revID = $this->getRevisionId();
                return $revID == 0 || $revID == $this->getTitle()->getLatestRevID();
        }

        /**
         * Set the "relevant" title
         * @see self::getRelevantTitle()
         * @param Title $t
         */
        public function setRelevantTitle( $t ) {
                $this->mRelevantTitle = $t;
        }

        /**
         * Return the "relevant" title.
         * A "relevant" title is not necessarily the actual title of the page.
         * Special pages like Special:MovePage use set the page they are acting on
         * as their "relevant" title, this allows the skin system to display things
         * such as content tabs which belong to to that page instead of displaying
         * a basic special page tab which has almost no meaning.
         *
         * @return Title
         */
        public function getRelevantTitle() {
                if ( isset( $this->mRelevantTitle ) ) {
                        return $this->mRelevantTitle;
                }
                return $this->getTitle();
        }

        /**
         * Set the "relevant" user
         * @see self::getRelevantUser()
         * @param User $u
         */
        public function setRelevantUser( $u ) {
                $this->mRelevantUser = $u;
        }

        /**
         * Return the "relevant" user.
         * A "relevant" user is similar to a relevant title. Special pages like
         * Special:Contributions mark the user which they are relevant to so that
         * things like the toolbox can display the information they usually are only
         * able to display on a user's userpage and talkpage.
         * @return User
         */
        public function getRelevantUser() {
                if ( isset( $this->mRelevantUser ) ) {
                        return $this->mRelevantUser;
                }
                $title = $this->getRelevantTitle();
                if ( $title->hasSubjectNamespace( NS_USER ) ) {
                        $rootUser = $title->getRootText();
                        if ( User::isIP( $rootUser ) ) {
                                $this->mRelevantUser = User::newFromName( $rootUser, false );
                        } else {
                                $user = User::newFromName( $rootUser, false );

                                if ( $user ) {
                                        $user->load( User::READ_NORMAL );

                                        if ( $user->isLoggedIn() ) {
                                                $this->mRelevantUser = $user;
                                        }
                                }
                        }
                        return $this->mRelevantUser;
                }
                return null;
        }

        /**
         * Outputs the HTML generated by other functions.
         * @param OutputPage $out
         */
        abstract function outputPage( OutputPage $out = null );

        /**
         * @param array $data
         * @return string
         */
        static function makeVariablesScript( $data ) {
                if ( $data ) {
                        return ResourceLoader::makeInlineScript(
                                ResourceLoader::makeConfigSetScript( $data )
                        );
                } else {
                        return '';
                }
        }

        /**
         * Get the query to generate a dynamic stylesheet
         *
         * @return array
         */
        public static function getDynamicStylesheetQuery() {
                global $wgSquidMaxage;

                return array(
                                'action' => 'raw',
                                'maxage' => $wgSquidMaxage,
                                'usemsgcache' => 'yes',
                                'ctype' => 'text/css',
                                'smaxage' => $wgSquidMaxage,
                        );
        }

        /**
         * Add skin specific stylesheets
         * Calling this method with an $out of anything but the same OutputPage
         * inside ->getOutput() is deprecated. The $out arg is kept
         * for compatibility purposes with skins.
         * @param OutputPage $out
         * @todo delete
         */
        abstract function setupSkinUserCss( OutputPage $out );

        /**
         * TODO: document
         * @param Title $title
         * @return string
         */
        function getPageClasses( $title ) {
                $numeric = 'ns-' . $title->getNamespace();

                if ( $title->isSpecialPage() ) {
                        $type = 'ns-special';
                        // bug 23315: provide a class based on the canonical special page name without subpages
                        list( $canonicalName ) = SpecialPageFactory::resolveAlias( $title->getDBkey() );
                        if ( $canonicalName ) {
                                $type .= ' ' . Sanitizer::escapeClass( "mw-special-$canonicalName" );
                        } else {
                                $type .= ' mw-invalidspecialpage';
                        }
                } elseif ( $title->isTalkPage() ) {
                        $type = 'ns-talk';
                } else {
                        $type = 'ns-subject';
                }

                $name = Sanitizer::escapeClass( 'page-' . $title->getPrefixedText() );

                return "$numeric $type $name";
        }

        /**
         * Return values for <html> element
         * @return array Array of associative name-to-value elements for <html> element
         */
        public function getHtmlElementAttributes() {
                $lang = $this->getLanguage();
                return array(
                        'lang' => $lang->getHtmlCode(),
                        'dir' => $lang->getDir(),
                        'class' => 'client-nojs',
                );
        }

        /**
         * This will be called by OutputPage::headElement when it is creating the
         * "<body>" tag, skins can override it if they have a need to add in any
         * body attributes or classes of their own.
         * @param OutputPage $out
         * @param array $bodyAttrs
         */
        function addToBodyAttributes( $out, &$bodyAttrs ) {
                // does nothing by default
        }

        /**
         * URL to the logo
         * @return string
         */
        function getLogo() {
                global $wgLogo;
                return $wgLogo;
        }

        /**
         * @return string
         */
        function getCategoryLinks() {
                global $wgUseCategoryBrowser;

                $out = $this->getOutput();
                $allCats = $out->getCategoryLinks();

                if ( !count( $allCats ) ) {
                        return '';
                }

                $embed = "<li>";
                $pop = "</li>";

                $s = '';
                $colon = $this->msg( 'colon-separator' )->escaped();

                if ( !empty( $allCats['normal'] ) ) {
                        $t = $embed . implode( "{$pop}{$embed}", $allCats['normal'] ) . $pop;

                        $msg = $this->msg( 'pagecategories' )->numParams( count( $allCats['normal'] ) )->escaped();
                        $linkPage = wfMessage( 'pagecategorieslink' )->inContentLanguage()->text();
                        $title = Title::newFromText( $linkPage );
                        $link = $title ? Linker::link( $title, $msg ) : $msg;
                        $s .= '<div id="mw-normal-catlinks" class="mw-normal-catlinks">' .
                                $link . $colon . '<ul>' . $t . '</ul>' . '</div>';
                }

                # Hidden categories
                if ( isset( $allCats['hidden'] ) ) {
                        if ( $this->getUser()->getBoolOption( 'showhiddencats' ) ) {
                                $class = ' mw-hidden-cats-user-shown';
                        } elseif ( $this->getTitle()->getNamespace() == NS_CATEGORY ) {
                                $class = ' mw-hidden-cats-ns-shown';
                        } else {
                                $class = ' mw-hidden-cats-hidden';
                        }

                        $s .= "<div id=\"mw-hidden-catlinks\" class=\"mw-hidden-catlinks$class\">" .
                                $this->msg( 'hidden-categories' )->numParams( count( $allCats['hidden'] ) )->escaped() .
                                $colon . '<ul>' . $embed . implode( "{$pop}{$embed}", $allCats['hidden'] ) . $pop . '</ul>' .
                                '</div>';
                }

                # optional 'dmoz-like' category browser. Will be shown under the list
                # of categories an article belong to
                if ( $wgUseCategoryBrowser ) {
                        $s .= '<br /><hr />';

                        # get a big array of the parents tree
                        $parenttree = $this->getTitle()->getParentCategoryTree();
                        # Skin object passed by reference cause it can not be
                        # accessed under the method subfunction drawCategoryBrowser
                        $tempout = explode( "\n", $this->drawCategoryBrowser( $parenttree ) );
                        # Clean out bogus first entry and sort them
                        unset( $tempout[0] );
                        asort( $tempout );
                        # Output one per line
                        $s .= implode( "<br />\n", $tempout );
                }

                return $s;
        }

        /**
         * Render the array as a series of links.
         * @param array $tree Categories tree returned by Title::getParentCategoryTree
         * @return string Separated by &gt;, terminate with "\n"
         */
        function drawCategoryBrowser( $tree ) {
                $return = '';

                foreach ( $tree as $element => $parent ) {
                        if ( empty( $parent ) ) {
                                # element start a new list
                                $return .= "\n";
                        } else {
                                # grab the others elements
                                $return .= $this->drawCategoryBrowser( $parent ) . ' &gt; ';
                        }

                        # add our current element to the list
                        $eltitle = Title::newFromText( $element );
                        $return .= Linker::link( $eltitle, htmlspecialchars( $eltitle->getText() ) );
                }

                return $return;
        }

        /**
         * @return string
         */
        function getCategories() {
                $out = $this->getOutput();

                $catlinks = $this->getCategoryLinks();

                $classes = 'catlinks';

                // Check what we're showing
                $allCats = $out->getCategoryLinks();
                $showHidden = $this->getUser()->getBoolOption( 'showhiddencats' ) ||
                                                $this->getTitle()->getNamespace() == NS_CATEGORY;

                if ( empty( $allCats['normal'] ) && !( !empty( $allCats['hidden'] ) && $showHidden ) ) {
                        $classes .= ' catlinks-allhidden';
                }

                return "<div id='catlinks' class='$classes' data-mw='interface'>{$catlinks}</div>";
        }

        /**
         * This runs a hook to allow extensions placing their stuff after content
         * and article metadata (e.g. categories).
         * Note: This function has nothing to do with afterContent().
         *
         * This hook is placed here in order to allow using the same hook for all
         * skins, both the SkinTemplate based ones and the older ones, which directly
         * use this class to get their data.
         *
         * The output of this function gets processed in SkinTemplate::outputPage() for
         * the SkinTemplate based skins, all other skins should directly echo it.
         *
         * @return string Empty by default, if not changed by any hook function.
         */
        protected function afterContentHook() {
                $data = '';

                if ( Hooks::run( 'SkinAfterContent', array( &$data, $this ) ) ) {
                        // adding just some spaces shouldn't toggle the output
                        // of the whole <div/>, so we use trim() here
                        if ( trim( $data ) != '' ) {
                                // Doing this here instead of in the skins to
                                // ensure that the div has the same ID in all
                                // skins
                                $data = "<div id='mw-data-after-content'>\n" .
                                        "\t$data\n" .
                                        "</div>\n";
                        }
                } else {
                        wfDebug( "Hook SkinAfterContent changed output processing.\n" );
                }

                return $data;
        }

        /**
         * Generate debug data HTML for displaying at the bottom of the main content
         * area.
         * @return string HTML containing debug data, if enabled (otherwise empty).
         */
        protected function generateDebugHTML() {
                return MWDebug::getHTMLDebugLog();
        }

        /**
         * This gets called shortly before the "</body>" tag.
         *
         * @return string HTML-wrapped JS code to be put before "</body>"
         */
        function bottomScripts() {
                // TODO and the suckage continues. This function is really just a wrapper around
                // OutputPage::getBottomScripts() which takes a Skin param. This should be cleaned
                // up at some point
                $bottomScriptText = $this->getOutput()->getBottomScripts();
                Hooks::run( 'SkinAfterBottomScripts', array( $this, &$bottomScriptText ) );

                return $bottomScriptText;
        }

        /**
         * Text with the permalink to the source page,
         * usually shown on the footer of a printed page
         *
         * @return string HTML text with an URL
         */
        function printSource() {
                $oldid = $this->getRevisionId();
                if ( $oldid ) {
                        $canonicalUrl = $this->getTitle()->getCanonicalURL( 'oldid=' . $oldid );
                        $url = htmlspecialchars( wfExpandIRI( $canonicalUrl ) );
                } else {
                        // oldid not available for non existing pages
                        $url = htmlspecialchars( wfExpandIRI( $this->getTitle()->getCanonicalURL() ) );
                }

                return $this->msg( 'retrievedfrom' )
                        ->rawParams( '<a dir="ltr" href="' . $url . '">' . $url . '</a>' )
                        ->parse();
        }

        /**
         * @return string HTML
         */
        function getUndeleteLink() {
                $action = $this->getRequest()->getVal( 'action', 'view' );

                if ( $this->getTitle()->userCan( 'deletedhistory', $this->getUser() ) &&
                        ( !$this->getTitle()->exists() || $action == 'history' ) ) {
                        $n = $this->getTitle()->isDeleted();

                        if ( $n ) {
                                if ( $this->getTitle()->quickUserCan( 'undelete', $this->getUser() ) ) {
                                        $msg = 'thisisdeleted';
                                } else {
                                        $msg = 'viewdeleted';
                                }

                                return $this->msg( $msg )->rawParams(
                                        Linker::linkKnown(
                                                SpecialPage::getTitleFor( 'Undelete', $this->getTitle()->getPrefixedDBkey() ),
                                                $this->msg( 'restorelink' )->numParams( $n )->escaped() )
                                        )->escaped();
                        }
                }

                return '';
        }

        /**
         * @return string
         */
        function subPageSubtitle() {
                $out = $this->getOutput();
                $subpages = '';

                if ( !Hooks::run( 'SkinSubPageSubtitle', array( &$subpages, $this, $out ) ) ) {
                        return $subpages;
                }

                if ( $out->isArticle() && MWNamespace::hasSubpages( $out->getTitle()->getNamespace() ) ) {
                        $ptext = $this->getTitle()->getPrefixedText();
                        if ( preg_match( '/\//', $ptext ) ) {
                                $links = explode( '/', $ptext );
                                array_pop( $links );
                                $c = 0;
                                $growinglink = '';
                                $display = '';
                                $lang = $this->getLanguage();

                                foreach ( $links as $link ) {
                                        $growinglink .= $link;
                                        $display .= $link;
                                        $linkObj = Title::newFromText( $growinglink );

                                        if ( is_object( $linkObj ) && $linkObj->isKnown() ) {
                                                $getlink = Linker::linkKnown(
                                                        $linkObj,
                                                        htmlspecialchars( $display )
                                                );

                                                $c++;

                                                if ( $c > 1 ) {
                                                        $subpages .= $lang->getDirMarkEntity() . $this->msg( 'pipe-separator' )->escaped();
                                                } else {
                                                        $subpages .= '&lt; ';
                                                }

                                                $subpages .= $getlink;
                                                $display = '';
                                        } else {
                                                $display .= '/';
                                        }
                                        $growinglink .= '/';
                                }
                        }
                }

                return $subpages;
        }

        /**
         * @deprecated since 1.27, feature removed
         * @return bool Always false
         */
        function showIPinHeader() {
                wfDeprecated( __METHOD__, '1.27' );
                return false;
        }

        /**
         * @return string
         */
        function getSearchLink() {
                $searchPage = SpecialPage::getTitleFor( 'Search' );
                return $searchPage->getLocalURL();
        }

        /**
         * @return string
         */
        function escapeSearchLink() {
                return htmlspecialchars( $this->getSearchLink() );
        }

        /**
         * @param string $type
         * @return string
         */
        function getCopyright( $type = 'detect' ) {
                global $wgRightsPage, $wgRightsUrl, $wgRightsText;

                if ( $type == 'detect' ) {
                        if ( !$this->isRevisionCurrent()
                                && !$this->msg( 'history_copyright' )->inContentLanguage()->isDisabled()
                        ) {
                                $type = 'history';
                        } else {
                                $type = 'normal';
                        }
                }

                if ( $type == 'history' ) {
                        $msg = 'history_copyright';
                } else {
                        $msg = 'copyright';
                }

                if ( $wgRightsPage ) {
                        $title = Title::newFromText( $wgRightsPage );
                        $link = Linker::linkKnown( $title, $wgRightsText );
                } elseif ( $wgRightsUrl ) {
                        $link = Linker::makeExternalLink( $wgRightsUrl, $wgRightsText );
                } elseif ( $wgRightsText ) {
                        $link = $wgRightsText;
                } else {
                        # Give up now
                        return '';
                }

                // Allow for site and per-namespace customization of copyright notice.
                // @todo Remove deprecated $forContent param from hook handlers and then remove here.
                $forContent = true;

                Hooks::run(
                        'SkinCopyrightFooter',
                        array( $this->getTitle(), $type, &$msg, &$link, &$forContent )
                );

                return $this->msg( $msg )->rawParams( $link )->text();
        }

        /**
         * @return null|string
         */
        function getCopyrightIcon() {
                global $wgRightsUrl, $wgRightsText, $wgRightsIcon, $wgCopyrightIcon;

                $out = '';

                if ( $wgCopyrightIcon ) {
                        $out = $wgCopyrightIcon;
                } elseif ( $wgRightsIcon ) {
                        $icon = htmlspecialchars( $wgRightsIcon );

                        if ( $wgRightsUrl ) {
                                $url = htmlspecialchars( $wgRightsUrl );
                                $out .= '<a href="' . $url . '">';
                        }

                        $text = htmlspecialchars( $wgRightsText );
                        $out .= "<img src=\"$icon\" alt=\"$text\" width=\"88\" height=\"31\" />";

                        if ( $wgRightsUrl ) {
                                $out .= '</a>';
                        }
                }

                return $out;
        }

        /**
         * Gets the powered by MediaWiki icon.
         * @return string
         */
        function getPoweredBy() {
                global $wgResourceBasePath;

                $url1 = htmlspecialchars(
                        "$wgResourceBasePath/resources/assets/poweredby_mediawiki_88x31.png"
                );
                $url1_5 = htmlspecialchars(
                        "$wgResourceBasePath/resources/assets/poweredby_mediawiki_132x47.png"
                );
                $url2 = htmlspecialchars(
                        "$wgResourceBasePath/resources/assets/poweredby_mediawiki_176x62.png"
                );
                $text = '<a href="//www.mediawiki.org/"><img src="' . $url1
                        . '" srcset="' . $url1_5 . ' 1.5x, ' . $url2 . ' 2x" '
                        . 'height="31" width="88" alt="Powered by MediaWiki" /></a>';
                Hooks::run( 'SkinGetPoweredBy', array( &$text, $this ) );
                return $text;
        }

        /**
         * Get the timestamp of the latest revision, formatted in user language
         *
         * @return string
         */
        protected function lastModified() {
                $timestamp = $this->getOutput()->getRevisionTimestamp();

                # No cached timestamp, load it from the database
                if ( $timestamp === null ) {
                        $timestamp = Revision::getTimestampFromId( $this->getTitle(), $this->getRevisionId() );
                }

                if ( $timestamp ) {
                        $d = $this->getLanguage()->userDate( $timestamp, $this->getUser() );
                        $t = $this->getLanguage()->userTime( $timestamp, $this->getUser() );
                        $s = ' ' . $this->msg( 'lastmodifiedat', $d, $t )->parse();
                } else {
                        $s = '';
                }

                if ( wfGetLB()->getLaggedSlaveMode() ) {
                        $s .= ' <strong>' . $this->msg( 'laggedslavemode' )->parse() . '</strong>';
                }

                return $s;
        }

        /**
         * @param string $align
         * @return string
         */
        function logoText( $align = '' ) {
                if ( $align != '' ) {
                        $a = " style='float: {$align};'";
                } else {
                        $a = '';
                }

                $mp = $this->msg( 'mainpage' )->escaped();
                $mptitle = Title::newMainPage();
                $url = ( is_object( $mptitle ) ? htmlspecialchars( $mptitle->getLocalURL() ) : '' );

                $logourl = $this->getLogo();
                $s = "<a href='{$url}'><img{$a} src='{$logourl}' alt='[{$mp}]' /></a>";

                return $s;
        }

        /**
         * Renders a $wgFooterIcons icon according to the method's arguments
         * @param array $icon The icon to build the html for, see $wgFooterIcons
         *   for the format of this array.
         * @param bool|string $withImage Whether to use the icon's image or output
         *   a text-only footericon.
         * @return string HTML
         */
        function makeFooterIcon( $icon, $withImage = 'withImage' ) {
                if ( is_string( $icon ) ) {
                        $html = $icon;
                } else { // Assuming array
                        $url = isset( $icon["url"] ) ? $icon["url"] : null;
                        unset( $icon["url"] );
                        if ( isset( $icon["src"] ) && $withImage === 'withImage' ) {
                                // do this the lazy way, just pass icon data as an attribute array
                                $html = Html::element( 'img', $icon );
                        } else {
                                $html = htmlspecialchars( $icon["alt"] );
                        }
                        if ( $url ) {
                                $html = Html::rawElement( 'a', array( "href" => $url ), $html );
                        }
                }
                return $html;
        }

        /**
         * Gets the link to the wiki's main page.
         * @return string
         */
        function mainPageLink() {
                $s = Linker::linkKnown(
                        Title::newMainPage(),
                        $this->msg( 'mainpage' )->escaped()
                );

                return $s;
        }

        /**
         * Returns an HTML link for use in the footer
         * @param string $desc The i18n message key for the link text
         * @param string $page The i18n message key for the page to link to
         * @return string HTML anchor
         */
        public function footerLink( $desc, $page ) {
                // if the link description has been set to "-" in the default language,
                if ( $this->msg( $desc )->inContentLanguage()->isDisabled() ) {
                        // then it is disabled, for all languages.
                        return '';
                } else {
                        // Otherwise, we display the link for the user, described in their
                        // language (which may or may not be the same as the default language),
                        // but we make the link target be the one site-wide page.
                        $title = Title::newFromText( $this->msg( $page )->inContentLanguage()->text() );

                        if ( !$title ) {
                                return '';
                        }

                        return Linker::linkKnown(
                                $title,
                                $this->msg( $desc )->escaped()
                        );
                }
        }

        /**
         * Gets the link to the wiki's privacy policy page.
         * @return string HTML
         */
        function privacyLink() {
                return $this->footerLink( 'privacy', 'privacypage' );
        }

        /**
         * Gets the link to the wiki's about page.
         * @return string HTML
         */
        function aboutLink() {
                return $this->footerLink( 'aboutsite', 'aboutpage' );
        }

        /**
         * Gets the link to the wiki's general disclaimers page.
         * @return string HTML
         */
        function disclaimerLink() {
                return $this->footerLink( 'disclaimers', 'disclaimerpage' );
        }

        /**
         * Return URL options for the 'edit page' link.
         * This may include an 'oldid' specifier, if the current page view is such.
         *
         * @return array
         * @private
         */
        function editUrlOptions() {
                $options = array( 'action' => 'edit' );

                if ( !$this->isRevisionCurrent() ) {
                        $options['oldid'] = intval( $this->getRevisionId() );
                }

                return $options;
        }

        /**
         * @param User|int $id
         * @return bool
         */
        function showEmailUser( $id ) {
                if ( $id instanceof User ) {
                        $targetUser = $id;
                } else {
                        $targetUser = User::newFromId( $id );
                }

                # The sending user must have a confirmed email address and the target
                # user must have a confirmed email address and allow emails from users.
                return $this->getUser()->canSendEmail() &&
                        $targetUser->canReceiveEmail();
        }

        /**
         * This function previously returned a fully resolved style path URL to images or styles stored in
         * the legacy skins/common/ directory.
         *
         * That directory has been removed in 1.24 and the function always returns an empty string.
         *
         * @deprecated since 1.24
         * @param string $name The name or path of a skin resource file
         * @return string Empty string
         */
        function getCommonStylePath( $name ) {
                wfDeprecated( __METHOD__, '1.24' );
                return '';
        }

        /**
         * Return a fully resolved style path url to images or styles stored in the current skins's folder.
         * This method returns a url resolved using the configured skin style path
         * and includes the style version inside of the url.
         *
         * Requires $stylename to be set, otherwise throws MWException.
         *
         * @param string $name The name or path of a skin resource file
         * @return string The fully resolved style path url including styleversion
         * @throws MWException
         */
        function getSkinStylePath( $name ) {
                global $wgStylePath, $wgStyleVersion;

                if ( $this->stylename === null ) {
                        $class = get_class( $this );
                        throw new MWException( "$class::\$stylename must be set to use getSkinStylePath()" );
                }

                return "$wgStylePath/{$this->stylename}/$name?$wgStyleVersion";
        }

        /* these are used extensively in SkinTemplate, but also some other places */

        /**
         * @param string $urlaction
         * @return string
         */
        static function makeMainPageUrl( $urlaction = '' ) {
                $title = Title::newMainPage();
                self::checkTitle( $title, '' );

                return $title->getLocalURL( $urlaction );
        }

        /**
         * Make a URL for a Special Page using the given query and protocol.
         *
         * If $proto is set to null, make a local URL. Otherwise, make a full
         * URL with the protocol specified.
         *
         * @param string $name Name of the Special page
         * @param string $urlaction Query to append
         * @param string|null $proto Protocol to use or null for a local URL
         * @return string
         */
        static function makeSpecialUrl( $name, $urlaction = '', $proto = null ) {
                $title = SpecialPage::getSafeTitleFor( $name );
                if ( is_null( $proto ) ) {
                        return $title->getLocalURL( $urlaction );
                } else {
                        return $title->getFullURL( $urlaction, false, $proto );
                }
        }

        /**
         * @param string $name
         * @param string $subpage
         * @param string $urlaction
         * @return string
         */
        static function makeSpecialUrlSubpage( $name, $subpage, $urlaction = '' ) {
                $title = SpecialPage::getSafeTitleFor( $name, $subpage );
                return $title->getLocalURL( $urlaction );
        }

        /**
         * @param string $name
         * @param string $urlaction
         * @return string
         */
        static function makeI18nUrl( $name, $urlaction = '' ) {
                $title = Title::newFromText( wfMessage( $name )->inContentLanguage()->text() );
                self::checkTitle( $title, $name );
                return $title->getLocalURL( $urlaction );
        }

        /**
         * @param string $name
         * @param string $urlaction
         * @return string
         */
        static function makeUrl( $name, $urlaction = '' ) {
                $title = Title::newFromText( $name );
                self::checkTitle( $title, $name );

                return $title->getLocalURL( $urlaction );
        }

        /**
         * If url string starts with http, consider as external URL, else
         * internal
         * @param string $name
         * @return string URL
         */
        static function makeInternalOrExternalUrl( $name ) {
                if ( preg_match( '/^(?i:' . wfUrlProtocols() . ')/', $name ) ) {
                        return $name;
                } else {
                        return self::makeUrl( $name );
                }
        }

        /**
         * this can be passed the NS number as defined in Language.php
         * @param string $name
         * @param string $urlaction
         * @param int $namespace
         * @return string
         */
        static function makeNSUrl( $name, $urlaction = '', $namespace = NS_MAIN ) {
                $title = Title::makeTitleSafe( $namespace, $name );
                self::checkTitle( $title, $name );

                return $title->getLocalURL( $urlaction );
        }

        /**
         * these return an array with the 'href' and boolean 'exists'
         * @param string $name
         * @param string $urlaction
         * @return array
         */
        static function makeUrlDetails( $name, $urlaction = '' ) {
                $title = Title::newFromText( $name );
                self::checkTitle( $title, $name );

                return array(
                        'href' => $title->getLocalURL( $urlaction ),
                        'exists' => $title->isKnown(),
                );
        }

        /**
         * Make URL details where the article exists (or at least it's convenient to think so)
         * @param string $name Article name
         * @param string $urlaction
         * @return array
         */
        static function makeKnownUrlDetails( $name, $urlaction = '' ) {
                $title = Title::newFromText( $name );
                self::checkTitle( $title, $name );

                return array(
                        'href' => $title->getLocalURL( $urlaction ),
                        'exists' => true
                );
        }

        /**
         * make sure we have some title to operate on
         *
         * @param Title $title
         * @param string $name
         */
        static function checkTitle( &$title, $name ) {
                if ( !is_object( $title ) ) {
                        $title = Title::newFromText( $name );
                        if ( !is_object( $title ) ) {
                                $title = Title::newFromText( '--error: link target missing--' );
                        }
                }
        }

        /**
         * Build an array that represents the sidebar(s), the navigation bar among them.
         *
         * BaseTemplate::getSidebar can be used to simplify the format and id generation in new skins.
         *
         * The format of the returned array is array( heading => content, ... ), where:
         * - heading is the heading of a navigation portlet. It is either:
         *   - magic string to be handled by the skins ('SEARCH' / 'LANGUAGES' / 'TOOLBOX' / ...)
         *   - a message name (e.g. 'navigation'), the message should be HTML-escaped by the skin
         *   - plain text, which should be HTML-escaped by the skin
         * - content is the contents of the portlet. It is either:
         *   - HTML text (<ul><li>...</li>...</ul>)
         *   - array of link data in a format accepted by BaseTemplate::makeListItem()
         *   - (for a magic string as a key, any value)
         *
         * Note that extensions can control the sidebar contents using the SkinBuildSidebar hook
         * and can technically insert anything in here; skin creators are expected to handle
         * values described above.
         *
         * @return array
         */
        function buildSidebar() {
                global $wgEnableSidebarCache, $wgSidebarCacheExpiry;

                $that = $this;
                $callback = function () use ( $that ) {
                        $bar = array();
                        $that->addToSidebar( $bar, 'sidebar' );
                        Hooks::run( 'SkinBuildSidebar', array( $that, &$bar ) );

                        return $bar;
                };

                if ( $wgEnableSidebarCache ) {
                        $cache = ObjectCache::getMainWANInstance();
                        $sidebar = $cache->getWithSetCallback(
                                $cache->makeKey( 'sidebar', $this->getLanguage()->getCode() ),
                                $wgSidebarCacheExpiry,
                                $callback,
                                array( 'lockTSE' => 30 )
                        );
                } else {
                        $sidebar = $callback();
                }

                // Apply post-processing to the cached value
                Hooks::run( 'SidebarBeforeOutput', array( $this, &$sidebar ) );

                return $sidebar;
        }

        /**
         * Add content from a sidebar system message
         * Currently only used for MediaWiki:Sidebar (but may be used by Extensions)
         *
         * This is just a wrapper around addToSidebarPlain() for backwards compatibility
         *
         * @param array $bar
         * @param string $message
         */
        public function addToSidebar( &$bar, $message ) {
                $this->addToSidebarPlain( $bar, wfMessage( $message )->inContentLanguage()->plain() );
        }

        /**
         * Add content from plain text
         * @since 1.17
         * @param array $bar
         * @param string $text
         * @return array
         */
        function addToSidebarPlain( &$bar, $text ) {
                $lines = explode( "\n", $text );

                $heading = '';

                foreach ( $lines as $line ) {
                        if ( strpos( $line, '*' ) !== 0 ) {
                                continue;
                        }
                        $line = rtrim( $line, "\r" ); // for Windows compat

                        if ( strpos( $line, '**' ) !== 0 ) {
                                $heading = trim( $line, '* ' );
                                if ( !array_key_exists( $heading, $bar ) ) {
                                        $bar[$heading] = array();
                                }
                        } else {
                                $line = trim( $line, '* ' );

                                if ( strpos( $line, '|' ) !== false ) { // sanity check
                                        $line = MessageCache::singleton()->transform( $line, false, null, $this->getTitle() );
                                        $line = array_map( 'trim', explode( '|', $line, 2 ) );
                                        if ( count( $line ) !== 2 ) {
                                                // Second sanity check, could be hit by people doing
                                                // funky stuff with parserfuncs... (bug 33321)
                                                continue;
                                        }

                                        $extraAttribs = array();

                                        $msgLink = $this->msg( $line[0] )->inContentLanguage();
                                        if ( $msgLink->exists() ) {
                                                $link = $msgLink->text();
                                                if ( $link == '-' ) {
                                                        continue;
                                                }
                                        } else {
                                                $link = $line[0];
                                        }
                                        $msgText = $this->msg( $line[1] );
                                        if ( $msgText->exists() ) {
                                                $text = $msgText->text();
                                        } else {
                                                $text = $line[1];
                                        }

                                        if ( preg_match( '/^(?i:' . wfUrlProtocols() . ')/', $link ) ) {
                                                $href = $link;

                                                // Parser::getExternalLinkAttribs won't work here because of the Namespace things
                                                global $wgNoFollowLinks, $wgNoFollowDomainExceptions;
                                                if ( $wgNoFollowLinks && !wfMatchesDomainList( $href, $wgNoFollowDomainExceptions ) ) {
                                                        $extraAttribs['rel'] = 'nofollow';
                                                }

                                                global $wgExternalLinkTarget;
                                                if ( $wgExternalLinkTarget ) {
                                                        $extraAttribs['target'] = $wgExternalLinkTarget;
                                                }
                                        } else {
                                                $title = Title::newFromText( $link );

                                                if ( $title ) {
                                                        $title = $title->fixSpecialName();
                                                        $href = $title->getLinkURL();
                                                } else {
                                                        $href = 'INVALID-TITLE';
                                                }
                                        }

                                        $bar[$heading][] = array_merge( array(
                                                'text' => $text,
                                                'href' => $href,
                                                'id' => 'n-' . Sanitizer::escapeId( strtr( $line[1], ' ', '-' ), 'noninitial' ),
                                                'active' => false
                                        ), $extraAttribs );
                                } else {
                                        continue;
                                }
                        }
                }

                return $bar;
        }

        /**
         * This function previously controlled whether the 'mediawiki.legacy.wikiprintable' module
         * should be loaded by OutputPage. That module no longer exists and the return value of this
         * method is ignored.
         *
         * If your skin doesn't provide its own print styles, the 'mediawiki.legacy.commonPrint' module
         * can be used instead (SkinTemplate-based skins do it automatically).
         *
         * @deprecated since 1.22
         * @return bool
         */
        public function commonPrintStylesheet() {
                wfDeprecated( __METHOD__, '1.22' );
                return false;
        }

        /**
         * Gets new talk page messages for the current user and returns an
         * appropriate alert message (or an empty string if there are no messages)
         * @return string
         */
        function getNewtalks() {

                $newMessagesAlert = '';
                $user = $this->getUser();
                $newtalks = $user->getNewMessageLinks();
                $out = $this->getOutput();

                // Allow extensions to disable or modify the new messages alert
                if ( !Hooks::run( 'GetNewMessagesAlert', array( &$newMessagesAlert, $newtalks, $user, $out ) ) ) {
                        return '';
                }
                if ( $newMessagesAlert ) {
                        return $newMessagesAlert;
                }

                if ( count( $newtalks ) == 1 && $newtalks[0]['wiki'] === wfWikiID() ) {
                        $uTalkTitle = $user->getTalkPage();
                        $lastSeenRev = isset( $newtalks[0]['rev'] ) ? $newtalks[0]['rev'] : null;
                        $nofAuthors = 0;
                        if ( $lastSeenRev !== null ) {
                                $plural = true; // Default if we have a last seen revision: if unknown, use plural
                                $latestRev = Revision::newFromTitle( $uTalkTitle, false, Revision::READ_NORMAL );
                                if ( $latestRev !== null ) {
                                        // Singular if only 1 unseen revision, plural if several unseen revisions.
                                        $plural = $latestRev->getParentId() !== $lastSeenRev->getId();
                                        $nofAuthors = $uTalkTitle->countAuthorsBetween(
                                                $lastSeenRev, $latestRev, 10, 'include_new' );
                                }
                        } else {
                                // Singular if no revision -> diff link will show latest change only in any case
                                $plural = false;
                        }
                        $plural = $plural ? 999 : 1;
                        // 999 signifies "more than one revision". We don't know how many, and even if we did,
                        // the number of revisions or authors is not necessarily the same as the number of
                        // "messages".
                        $newMessagesLink = Linker::linkKnown(
                                $uTalkTitle,
                                $this->msg( 'newmessageslinkplural' )->params( $plural )->escaped(),
                                array(),
                                array( 'redirect' => 'no' )
                        );

                        $newMessagesDiffLink = Linker::linkKnown(
                                $uTalkTitle,
                                $this->msg( 'newmessagesdifflinkplural' )->params( $plural )->escaped(),
                                array(),
                                $lastSeenRev !== null
                                        ? array( 'oldid' => $lastSeenRev->getId(), 'diff' => 'cur' )
                                        : array( 'diff' => 'cur' )
                        );

                        if ( $nofAuthors >= 1 && $nofAuthors <= 10 ) {
                                $newMessagesAlert = $this->msg(
                                        'youhavenewmessagesfromusers',
                                        $newMessagesLink,
                                        $newMessagesDiffLink
                                )->numParams( $nofAuthors, $plural );
                        } else {
                                // $nofAuthors === 11 signifies "11 or more" ("more than 10")
                                $newMessagesAlert = $this->msg(
                                        $nofAuthors > 10 ? 'youhavenewmessagesmanyusers' : 'youhavenewmessages',
                                        $newMessagesLink,
                                        $newMessagesDiffLink
                                )->numParams( $plural );
                        }
                        $newMessagesAlert = $newMessagesAlert->text();
                        # Disable CDN cache
                        $out->setCdnMaxage( 0 );
                } elseif ( count( $newtalks ) ) {
                        $sep = $this->msg( 'newtalkseparator' )->escaped();
                        $msgs = array();

                        foreach ( $newtalks as $newtalk ) {
                                $msgs[] = Xml::element(
                                        'a',
                                        array( 'href' => $newtalk['link'] ), $newtalk['wiki']
                                );
                        }
                        $parts = implode( $sep, $msgs );
                        $newMessagesAlert = $this->msg( 'youhavenewmessagesmulti' )->rawParams( $parts )->escaped();
                        $out->setCdnMaxage( 0 );
                }

                return $newMessagesAlert;
        }

        /**
         * Get a cached notice
         *
         * @param string $name Message name, or 'default' for $wgSiteNotice
         * @return string|bool HTML fragment, or false to indicate that the caller
         *   should fall back to the next notice in its sequence
         */
        private function getCachedNotice( $name ) {
                global $wgRenderHashAppend, $parserMemc, $wgContLang;

                $needParse = false;

                if ( $name === 'default' ) {
                        // special case
                        global $wgSiteNotice;
                        $notice = $wgSiteNotice;
                        if ( empty( $notice ) ) {
                                return false;
                        }
                } else {
                        $msg = $this->msg( $name )->inContentLanguage();
                        if ( $msg->isBlank() ) {
                                return '';
                        } elseif ( $msg->isDisabled() ) {
                                return false;
                        }
                        $notice = $msg->plain();
                }

                // Use the extra hash appender to let eg SSL variants separately cache.
                $key = wfMemcKey( $name . $wgRenderHashAppend );
                $cachedNotice = $parserMemc->get( $key );
                if ( is_array( $cachedNotice ) ) {
                        if ( md5( $notice ) == $cachedNotice['hash'] ) {
                                $notice = $cachedNotice['html'];
                        } else {
                                $needParse = true;
                        }
                } else {
                        $needParse = true;
                }

                if ( $needParse ) {
                        $parsed = $this->getOutput()->parse( $notice );
                        $parserMemc->set( $key, array( 'html' => $parsed, 'hash' => md5( $notice ) ), 600 );
                        $notice = $parsed;
                }

                $notice = Html::rawElement( 'div', array( 'id' => 'localNotice',
                        'lang' => $wgContLang->getHtmlCode(), 'dir' => $wgContLang->getDir() ), $notice );
                return $notice;
        }

        /**
         * Get the site notice
         *
         * @return string HTML fragment
         */
        function getSiteNotice() {
                $siteNotice = '';

                if ( Hooks::run( 'SiteNoticeBefore', array( &$siteNotice, $this ) ) ) {
                        if ( is_object( $this->getUser() ) && $this->getUser()->isLoggedIn() ) {
                                $siteNotice = $this->getCachedNotice( 'sitenotice' );
                        } else {
                                $anonNotice = $this->getCachedNotice( 'anonnotice' );
                                if ( $anonNotice === false ) {
                                        $siteNotice = $this->getCachedNotice( 'sitenotice' );
                                } else {
                                        $siteNotice = $anonNotice;
                                }
                        }
                        if ( $siteNotice === false ) {
                                $siteNotice = $this->getCachedNotice( 'default' );
                        }
                }

                Hooks::run( 'SiteNoticeAfter', array( &$siteNotice, $this ) );
                return $siteNotice;
        }

        /**
         * Create a section edit link.  This supersedes editSectionLink() and
         * editSectionLinkForOther().
         *
         * @param Title $nt The title being linked to (may not be the same as
         *   the current page, if the section is included from a template)
         * @param string $section The designation of the section being pointed to,
         *   to be included in the link, like "&section=$section"
         * @param string $tooltip The tooltip to use for the link: will be escaped
         *   and wrapped in the 'editsectionhint' message
         * @param string $lang Language code
         * @return string HTML to use for edit link
         */
        public function doEditSectionLink( Title $nt, $section, $tooltip = null, $lang = false ) {
                // HTML generated here should probably have userlangattributes
                // added to it for LTR text on RTL pages

                $lang = wfGetLangObj( $lang );

                $attribs = array();
                if ( !is_null( $tooltip ) ) {
                        # Bug 25462: undo double-escaping.
                        $tooltip = Sanitizer::decodeCharReferences( $tooltip );
                        $attribs['title'] = wfMessage( 'editsectionhint' )->rawParams( $tooltip )
                                ->inLanguage( $lang )->text();
                }

                $links = array(
                        'editsection' => array(
                                'text' => wfMessage( 'editsection' )->inLanguage( $lang )->escaped(),
                                'targetTitle' => $nt,
                                'attribs' => $attribs,
                                'query' => array( 'action' => 'edit', 'section' => $section ),
                                'options' => array( 'noclasses', 'known' )
                        )
                );

                Hooks::run( 'SkinEditSectionLinks', array( $this, $nt, $section, $tooltip, &$links, $lang ) );

                $result = '<span class="mw-editsection"><span class="mw-editsection-bracket">[</span>';

                $linksHtml = array();
                foreach ( $links as $k => $linkDetails ) {
                        $linksHtml[] = Linker::link(
                                $linkDetails['targetTitle'],
                                $linkDetails['text'],
                                $linkDetails['attribs'],
                                $linkDetails['query'],
                                $linkDetails['options']
                        );
                }

                $result .= implode(
                        '<span class="mw-editsection-divider">'
                                . wfMessage( 'pipe-separator' )->inLanguage( $lang )->text()
                                . '</span>',
                        $linksHtml
                );

                $result .= '<span class="mw-editsection-bracket">]</span></span>';
                // Deprecated, use SkinEditSectionLinks hook instead
                Hooks::run(
                        'DoEditSectionLink',
                        array( $this, $nt, $section, $tooltip, &$result, $lang ),
                        '1.25'
                );
                return $result;
        }

        /**
         * Use PHP's magic __call handler to intercept legacy calls to the linker
         * for backwards compatibility.
         *
         * @param string $fname Name of called method
         * @param array $args Arguments to the method
         * @throws MWException
         * @return mixed
         */
        function __call( $fname, $args ) {
                $realFunction = array( 'Linker', $fname );
                if ( is_callable( $realFunction ) ) {
                        wfDeprecated( get_class( $this ) . '::' . $fname, '1.21' );
                        return call_user_func_array( $realFunction, $args );
                } else {
                        $className = get_class( $this );
                        throw new MWException( "Call to undefined method $className::$fname" );
                }
        }

}