OutputPage.php

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<?php
class OutputPage extends ContextSource {
    protected $mMetatags = array();

    protected $mLinktags = array();

    protected $mCanonicalUrl = false;

    protected $mExtStyles = array();

    public $mPagetitle = '';

    public $mBodytext = '';

    public $mDebugtext = '';

    private $mHTMLtitle = '';

    private $mIsarticle = false;

    private $mIsArticleRelated = true;

    private $mPrintable = false;

    private $mSubtitle = array();

    public $mRedirect = '';

    protected $mStatusCode;

    protected $mLastModified = '';

    private $mETag = false;

    protected $mCategoryLinks = array();

    protected $mCategories = array();

    private $mLanguageLinks = array();

    private $mScripts = '';

    protected $mInlineStyles = '';

    private $mLinkColours;

    public $mPageLinkTitle = '';

    protected $mHeadItems = array();

    // @todo FIXME: Next 5 variables probably come from the resource loader

    protected $mModules = array();

    protected $mModuleScripts = array();

    protected $mModuleStyles = array();

    protected $mModuleMessages = array();

    protected $mResourceLoader;

    protected $mJsConfigVars = array();

    protected $mTemplateIds = array();

    protected $mImageTimeKeys = array();

    public $mRedirectCode = '';

    protected $mFeedLinksAppendQuery = null;

    protected $mAllowedModuleOrigin = ResourceLoaderModule::ORIGIN_ALL;

    protected $mDoNothing = false;

    // Parser related.

    private $mContainsOldMagic = 0;

    protected $mContainsNewMagic = 0;

    protected $mParserOptions = null;

    private $mFeedLinks = array();

    // Gwicke work on squid caching? Roughly from 2003.
    protected $mEnableClientCache = true;

    private $mArticleBodyOnly = false;

    protected $mNewSectionLink = false;

    protected $mHideNewSectionLink = false;

    public $mNoGallery = false;

    private $mPageTitleActionText = '';

    private $mParseWarnings = array();

    protected $mSquidMaxage = 0;

    protected $mPreventClickjacking = true;

    private $mRevisionId = null;

    private $mRevisionTimestamp = null;

    protected $mFileVersion = null;

    protected $styles = array();

    protected $mJQueryDone = false;

    private $mIndexPolicy = 'index';
    private $mFollowPolicy = 'follow';
    private $mVaryHeader = array(
        'Accept-Encoding' => array( 'list-contains=gzip' ),
    );

    private $mRedirectedFrom = null;

    private $mProperties = array();

    private $mTarget = null;

    private $mEnableTOC = true;

    private $mEnableSectionEditLinks = true;

    function __construct( IContextSource $context = null ) {
        if ( $context === null ) {
            # Extensions should use `new RequestContext` instead of `new OutputPage` now.
            wfDeprecated( __METHOD__, '1.18' );
        } else {
            $this->setContext( $context );
        }
    }

    public function redirect( $url, $responsecode = '302' ) {
        # Strip newlines as a paranoia check for header injection in PHP<5.1.2
        $this->mRedirect = str_replace( "\n", '', $url );
        $this->mRedirectCode = $responsecode;
    }

    public function getRedirect() {
        return $this->mRedirect;
    }

    public function setStatusCode( $statusCode ) {
        $this->mStatusCode = $statusCode;
    }

    function addMeta( $name, $val ) {
        array_push( $this->mMetatags, array( $name, $val ) );
    }

    function addLink( array $linkarr ) {
        array_push( $this->mLinktags, $linkarr );
    }

    function addMetadataLink( array $linkarr ) {
        $linkarr['rel'] = $this->getMetadataAttribute();
        $this->addLink( $linkarr );
    }

    function setCanonicalUrl( $url ) {
        $this->mCanonicalUrl = $url;
    }

    public function getMetadataAttribute() {
        # note: buggy CC software only reads first "meta" link
        static $haveMeta = false;
        if ( $haveMeta ) {
            return 'alternate meta';
        } else {
            $haveMeta = true;
            return 'meta';
        }
    }

    function addScript( $script ) {
        $this->mScripts .= $script . "\n";
    }

    public function addExtensionStyle( $url ) {
        array_push( $this->mExtStyles, $url );
    }

    function getExtStyle() {
        return $this->mExtStyles;
    }

    public function addScriptFile( $file, $version = null ) {
        // See if $file parameter is an absolute URL or begins with a slash
        if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
            $path = $file;
        } else {
            $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
        }
        if ( is_null( $version ) ) {
            $version = $this->getConfig()->get( 'StyleVersion' );
        }
        $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
    }

    public function addInlineScript( $script ) {
        $this->mScripts .= Html::inlineScript( "\n$script\n" ) . "\n";
    }

    function getScript() {
        wfDeprecated( __METHOD__, '1.24' );
        return $this->mScripts . $this->getHeadItems();
    }

    protected function filterModules( array $modules, $position = null,
        $type = ResourceLoaderModule::TYPE_COMBINED
    ) {
        $resourceLoader = $this->getResourceLoader();
        $filteredModules = array();
        foreach ( $modules as $val ) {
            $module = $resourceLoader->getModule( $val );
            if ( $module instanceof ResourceLoaderModule
                && $module->getOrigin() <= $this->getAllowedModules( $type )
                && ( is_null( $position ) || $module->getPosition() == $position )
                && ( !$this->mTarget || in_array( $this->mTarget, $module->getTargets() ) )
            ) {
                $filteredModules[] = $val;
            }
        }
        return $filteredModules;
    }

    public function getModules( $filter = false, $position = null, $param = 'mModules' ) {
        $modules = array_values( array_unique( $this->$param ) );
        return $filter
            ? $this->filterModules( $modules, $position )
            : $modules;
    }

    public function addModules( $modules ) {
        $this->mModules = array_merge( $this->mModules, (array)$modules );
    }

    public function getModuleScripts( $filter = false, $position = null ) {
        return $this->getModules( $filter, $position, 'mModuleScripts' );
    }

    public function addModuleScripts( $modules ) {
        $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
    }

    public function getModuleStyles( $filter = false, $position = null ) {
        return $this->getModules( $filter, $position, 'mModuleStyles' );
    }

    public function addModuleStyles( $modules ) {
        $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
    }

    public function getModuleMessages( $filter = false, $position = null ) {
        return $this->getModules( $filter, $position, 'mModuleMessages' );
    }

    public function addModuleMessages( $modules ) {
        $this->mModuleMessages = array_merge( $this->mModuleMessages, (array)$modules );
    }

    public function getTarget() {
        return $this->mTarget;
    }

    public function setTarget( $target ) {
        $this->mTarget = $target;
    }

    function getHeadItemsArray() {
        return $this->mHeadItems;
    }

    function getHeadItems() {
        wfDeprecated( __METHOD__, '1.24' );
        $s = '';
        foreach ( $this->mHeadItems as $item ) {
            $s .= $item;
        }
        return $s;
    }

    public function addHeadItem( $name, $value ) {
        $this->mHeadItems[$name] = $value;
    }

    public function hasHeadItem( $name ) {
        return isset( $this->mHeadItems[$name] );
    }

    function setETag( $tag ) {
        $this->mETag = $tag;
    }

    public function setArticleBodyOnly( $only ) {
        $this->mArticleBodyOnly = $only;
    }

    public function getArticleBodyOnly() {
        return $this->mArticleBodyOnly;
    }

    public function setProperty( $name, $value ) {
        $this->mProperties[$name] = $value;
    }

    public function getProperty( $name ) {
        if ( isset( $this->mProperties[$name] ) ) {
            return $this->mProperties[$name];
        } else {
            return null;
        }
    }

    public function checkLastModified( $timestamp ) {
        if ( !$timestamp || $timestamp == '19700101000000' ) {
            wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
            return false;
        }
        $config = $this->getConfig();
        if ( !$config->get( 'CachePages' ) ) {
            wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
            return false;
        }

        $timestamp = wfTimestamp( TS_MW, $timestamp );
        $modifiedTimes = array(
            'page' => $timestamp,
            'user' => $this->getUser()->getTouched(),
            'epoch' => $config->get( 'CacheEpoch' )
        );
        if ( $config->get( 'UseSquid' ) ) {
            // bug 44570: the core page itself may not change, but resources might
            $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
        }
        wfRunHooks( 'OutputPageCheckLastModified', array( &$modifiedTimes ) );

        $maxModified = max( $modifiedTimes );
        $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );

        $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
        if ( $clientHeader === false ) {
            wfDebug( __METHOD__ . ": client did not send If-Modified-Since header\n", 'log' );
            return false;
        }

        # IE sends sizes after the date like this:
        # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
        # this breaks strtotime().
        $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );

        wfSuppressWarnings(); // E_STRICT system time bitching
        $clientHeaderTime = strtotime( $clientHeader );
        wfRestoreWarnings();
        if ( !$clientHeaderTime ) {
            wfDebug( __METHOD__
                . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
            return false;
        }
        $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );

        # Make debug info
        $info = '';
        foreach ( $modifiedTimes as $name => $value ) {
            if ( $info !== '' ) {
                $info .= ', ';
            }
            $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
        }

        wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
            wfTimestamp( TS_ISO_8601, $clientHeaderTime ) . "\n", 'log' );
        wfDebug( __METHOD__ . ": effective Last-Modified: " .
            wfTimestamp( TS_ISO_8601, $maxModified ) . "\n", 'log' );
        if ( $clientHeaderTime < $maxModified ) {
            wfDebug( __METHOD__ . ": STALE, $info\n", 'log' );
            return false;
        }

        # Not modified
        # Give a 304 response code and disable body output
        wfDebug( __METHOD__ . ": NOT MODIFIED, $info\n", 'log' );
        ini_set( 'zlib.output_compression', 0 );
        $this->getRequest()->response()->header( "HTTP/1.1 304 Not Modified" );
        $this->sendCacheControl();
        $this->disable();

        // Don't output a compressed blob when using ob_gzhandler;
        // it's technically against HTTP spec and seems to confuse
        // Firefox when the response gets split over two packets.
        wfClearOutputBuffers();

        return true;
    }

    public function setLastModified( $timestamp ) {
        $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
    }

    public function setRobotPolicy( $policy ) {
        $policy = Article::formatRobotPolicy( $policy );

        if ( isset( $policy['index'] ) ) {
            $this->setIndexPolicy( $policy['index'] );
        }
        if ( isset( $policy['follow'] ) ) {
            $this->setFollowPolicy( $policy['follow'] );
        }
    }

    public function setIndexPolicy( $policy ) {
        $policy = trim( $policy );
        if ( in_array( $policy, array( 'index', 'noindex' ) ) ) {
            $this->mIndexPolicy = $policy;
        }
    }

    public function setFollowPolicy( $policy ) {
        $policy = trim( $policy );
        if ( in_array( $policy, array( 'follow', 'nofollow' ) ) ) {
            $this->mFollowPolicy = $policy;
        }
    }

    public function setPageTitleActionText( $text ) {
        $this->mPageTitleActionText = $text;
    }

    public function getPageTitleActionText() {
        return $this->mPageTitleActionText;
    }

    public function setHTMLTitle( $name ) {
        if ( $name instanceof Message ) {
            $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
        } else {
            $this->mHTMLtitle = $name;
        }
    }

    public function getHTMLTitle() {
        return $this->mHTMLtitle;
    }

    public function setRedirectedFrom( $t ) {
        $this->mRedirectedFrom = $t;
    }

    public function setPageTitle( $name ) {
        if ( $name instanceof Message ) {
            $name = $name->setContext( $this->getContext() )->text();
        }

        # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
        # but leave "<i>foobar</i>" alone
        $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
        $this->mPagetitle = $nameWithTags;

        # change "<i>foo&amp;bar</i>" to "foo&bar"
        $this->setHTMLTitle(
            $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
                ->inContentLanguage()
        );
    }

    public function getPageTitle() {
        return $this->mPagetitle;
    }

    public function setTitle( Title $t ) {
        $this->getContext()->setTitle( $t );
    }

    public function setSubtitle( $str ) {
        $this->clearSubtitle();
        $this->addSubtitle( $str );
    }

    public function appendSubtitle( $str ) {
        $this->addSubtitle( $str );
    }

    public function addSubtitle( $str ) {
        if ( $str instanceof Message ) {
            $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
        } else {
            $this->mSubtitle[] = $str;
        }
    }

    public function addBacklinkSubtitle( Title $title, $query = array() ) {
        if ( $title->isRedirect() ) {
            $query['redirect'] = 'no';
        }
        $this->addSubtitle( $this->msg( 'backlinksubtitle' )
            ->rawParams( Linker::link( $title, null, array(), $query ) ) );
    }

    public function clearSubtitle() {
        $this->mSubtitle = array();
    }

    public function getSubtitle() {
        return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
    }

    public function setPrintable() {
        $this->mPrintable = true;
    }

    public function isPrintable() {
        return $this->mPrintable;
    }

    public function disable() {
        $this->mDoNothing = true;
    }

    public function isDisabled() {
        return $this->mDoNothing;
    }

    public function showNewSectionLink() {
        return $this->mNewSectionLink;
    }

    public function forceHideNewSectionLink() {
        return $this->mHideNewSectionLink;
    }

    public function setSyndicated( $show = true ) {
        if ( $show ) {
            $this->setFeedAppendQuery( false );
        } else {
            $this->mFeedLinks = array();
        }
    }

    public function setFeedAppendQuery( $val ) {
        $this->mFeedLinks = array();

        foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
            $query = "feed=$type";
            if ( is_string( $val ) ) {
                $query .= '&' . $val;
            }
            $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
        }
    }

    public function addFeedLink( $format, $href ) {
        if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
            $this->mFeedLinks[$format] = $href;
        }
    }

    public function isSyndicated() {
        return count( $this->mFeedLinks ) > 0;
    }

    public function getSyndicationLinks() {
        return $this->mFeedLinks;
    }

    public function getFeedAppendQuery() {
        return $this->mFeedLinksAppendQuery;
    }

    public function setArticleFlag( $v ) {
        $this->mIsarticle = $v;
        if ( $v ) {
            $this->mIsArticleRelated = $v;
        }
    }

    public function isArticle() {
        return $this->mIsarticle;
    }

    public function setArticleRelated( $v ) {
        $this->mIsArticleRelated = $v;
        if ( !$v ) {
            $this->mIsarticle = false;
        }
    }

    public function isArticleRelated() {
        return $this->mIsArticleRelated;
    }

    public function addLanguageLinks( array $newLinkArray ) {
        $this->mLanguageLinks += $newLinkArray;
    }

    public function setLanguageLinks( array $newLinkArray ) {
        $this->mLanguageLinks = $newLinkArray;
    }

    public function getLanguageLinks() {
        return $this->mLanguageLinks;
    }

    public function addCategoryLinks( array $categories ) {
        global $wgContLang;

        if ( !is_array( $categories ) || count( $categories ) == 0 ) {
            return;
        }

        # Add the links to a LinkBatch
        $arr = array( NS_CATEGORY => $categories );
        $lb = new LinkBatch;
        $lb->setArray( $arr );

        # Fetch existence plus the hiddencat property
        $dbr = wfGetDB( DB_SLAVE );
        $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
            'page_is_redirect', 'page_latest', 'pp_value' );

        if ( $this->getConfig()->get( 'ContentHandlerUseDB' ) ) {
            $fields[] = 'page_content_model';
        }

        $res = $dbr->select( array( 'page', 'page_props' ),
            $fields,
            $lb->constructSet( 'page', $dbr ),
            __METHOD__,
            array(),
            array( 'page_props' => array( 'LEFT JOIN', array(
                'pp_propname' => 'hiddencat',
                'pp_page = page_id'
            ) ) )
        );

        # Add the results to the link cache
        $lb->addResultToCache( LinkCache::singleton(), $res );

        # Set all the values to 'normal'.
        $categories = array_fill_keys( array_keys( $categories ), 'normal' );

        # Mark hidden categories
        foreach ( $res as $row ) {
            if ( isset( $row->pp_value ) ) {
                $categories[$row->page_title] = 'hidden';
            }
        }

        # Add the remaining categories to the skin
        if ( wfRunHooks(
            'OutputPageMakeCategoryLinks',
            array( &$this, $categories, &$this->mCategoryLinks ) )
        ) {
            foreach ( $categories as $category => $type ) {
                $origcategory = $category;
                $title = Title::makeTitleSafe( NS_CATEGORY, $category );
                if ( !$title ) {
                    continue;
                }
                $wgContLang->findVariantLink( $category, $title, true );
                if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
                    continue;
                }
                $text = $wgContLang->convertHtml( $title->getText() );
                $this->mCategories[] = $title->getText();
                $this->mCategoryLinks[$type][] = Linker::link( $title, $text );
            }
        }
    }

    public function setCategoryLinks( array $categories ) {
        $this->mCategoryLinks = array();
        $this->addCategoryLinks( $categories );
    }

    public function getCategoryLinks() {
        return $this->mCategoryLinks;
    }

    public function getCategories() {
        return $this->mCategories;
    }

    public function disallowUserJs() {
        $this->reduceAllowedModuleOrigin( ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL );
    }

    public function getAllowedModules( $type = null ) {
        return $this->mAllowedModuleOrigin;
    }

    public function setAllowedModules( $type, $level ) {
        wfDeprecated( __METHOD__, '1.24' );
        $this->reduceAllowedModuleOrigin( $level );
    }

    public function reduceAllowedModules( $type, $level ) {
        wfDeprecated( __METHOD__, '1.24' );
        $this->reduceAllowedModuleOrigin( $level );
    }

    public function reduceAllowedModuleOrigin( $level ) {
        $this->mAllowedModuleOrigin = min( $this->mAllowedModuleOrigin, $level );
    }

    public function prependHTML( $text ) {
        $this->mBodytext = $text . $this->mBodytext;
    }

    public function addHTML( $text ) {
        $this->mBodytext .= $text;
    }

    public function addElement( $element, array $attribs = array(), $contents = '' ) {
        $this->addHTML( Html::element( $element, $attribs, $contents ) );
    }

    public function clearHTML() {
        $this->mBodytext = '';
    }

    public function getHTML() {
        return $this->mBodytext;
    }

    public function parserOptions( $options = null ) {
        if ( !$this->mParserOptions ) {
            $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
            $this->mParserOptions->setEditSection( false );
        }
        return wfSetVar( $this->mParserOptions, $options );
    }

    public function setRevisionId( $revid ) {
        $val = is_null( $revid ) ? null : intval( $revid );
        return wfSetVar( $this->mRevisionId, $val );
    }

    public function getRevisionId() {
        return $this->mRevisionId;
    }

    public function setRevisionTimestamp( $timestamp ) {
        return wfSetVar( $this->mRevisionTimestamp, $timestamp );
    }

    public function getRevisionTimestamp() {
        return $this->mRevisionTimestamp;
    }

    public function setFileVersion( $file ) {
        $val = null;
        if ( $file instanceof File && $file->exists() ) {
            $val = array( 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() );
        }
        return wfSetVar( $this->mFileVersion, $val, true );
    }

    public function getFileVersion() {
        return $this->mFileVersion;
    }

    public function getTemplateIds() {
        return $this->mTemplateIds;
    }

    public function getFileSearchOptions() {
        return $this->mImageTimeKeys;
    }

    public function addWikiText( $text, $linestart = true, $interface = true ) {
        $title = $this->getTitle(); // Work around E_STRICT
        if ( !$title ) {
            throw new MWException( 'Title is null' );
        }
        $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
    }

    public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
        $this->addWikiTextTitle( $text, $title, $linestart );
    }

    function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
        $this->addWikiTextTitle( $text, $title, $linestart, true );
    }

    public function addWikiTextTidy( $text, $linestart = true ) {
        $title = $this->getTitle();
        $this->addWikiTextTitleTidy( $text, $title, $linestart );
    }

    public function addWikiTextTitle( $text, Title $title, $linestart,
        $tidy = false, $interface = false
    ) {
        global $wgParser;

        wfProfileIn( __METHOD__ );

        $popts = $this->parserOptions();
        $oldTidy = $popts->setTidy( $tidy );
        $popts->setInterfaceMessage( (bool)$interface );

        $parserOutput = $wgParser->getFreshParser()->parse(
            $text, $title, $popts,
            $linestart, true, $this->mRevisionId
        );

        $popts->setTidy( $oldTidy );

        $this->addParserOutput( $parserOutput );

        wfProfileOut( __METHOD__ );
    }

    public function addParserOutputNoText( $parserOutput ) {
        $this->addParserOutputMetadata( $parserOutput );
    }

    public function addParserOutputMetadata( $parserOutput ) {
        $this->mLanguageLinks += $parserOutput->getLanguageLinks();
        $this->addCategoryLinks( $parserOutput->getCategories() );
        $this->mNewSectionLink = $parserOutput->getNewSection();
        $this->mHideNewSectionLink = $parserOutput->getHideNewSection();

        $this->mParseWarnings = $parserOutput->getWarnings();
        if ( !$parserOutput->isCacheable() ) {
            $this->enableClientCache( false );
        }
        $this->mNoGallery = $parserOutput->getNoGallery();
        $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
        $this->addModules( $parserOutput->getModules() );
        $this->addModuleScripts( $parserOutput->getModuleScripts() );
        $this->addModuleStyles( $parserOutput->getModuleStyles() );
        $this->addModuleMessages( $parserOutput->getModuleMessages() );
        $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
        $this->mPreventClickjacking = $this->mPreventClickjacking
            || $parserOutput->preventClickjacking();

        // Template versioning...
        foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
            if ( isset( $this->mTemplateIds[$ns] ) ) {
                $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
            } else {
                $this->mTemplateIds[$ns] = $dbks;
            }
        }
        // File versioning...
        foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
            $this->mImageTimeKeys[$dbk] = $data;
        }

        // Hooks registered in the object
        $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
        foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
            list( $hookName, $data ) = $hookInfo;
            if ( isset( $parserOutputHooks[$hookName] ) ) {
                call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
            }
        }

        // Link flags are ignored for now, but may in the future be
        // used to mark individual language links.
        $linkFlags = array();
        wfRunHooks( 'LanguageLinks', array( $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ) );
        wfRunHooks( 'OutputPageParserOutput', array( &$this, $parserOutput ) );
    }

    public function addParserOutputContent( $parserOutput ) {
        $this->addParserOutputText( $parserOutput );

        $this->addModules( $parserOutput->getModules() );
        $this->addModuleScripts( $parserOutput->getModuleScripts() );
        $this->addModuleStyles( $parserOutput->getModuleStyles() );
        $this->addModuleMessages( $parserOutput->getModuleMessages() );

        $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
    }

    public function addParserOutputText( $parserOutput ) {
        $text = $parserOutput->getText();
        wfRunHooks( 'OutputPageBeforeHTML', array( &$this, &$text ) );
        $this->addHTML( $text );
    }

    function addParserOutput( $parserOutput ) {
        $this->addParserOutputMetadata( $parserOutput );
        $parserOutput->setTOCEnabled( $this->mEnableTOC );

        // Touch section edit links only if not previously disabled
        if ( $parserOutput->getEditSectionTokens() ) {
            $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
        }

        $this->addParserOutputText( $parserOutput );
    }

    public function addTemplate( &$template ) {
        $this->addHTML( $template->getHTML() );
    }

    public function parse( $text, $linestart = true, $interface = false, $language = null ) {
        global $wgParser;

        if ( is_null( $this->getTitle() ) ) {
            throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
        }

        $popts = $this->parserOptions();
        if ( $interface ) {
            $popts->setInterfaceMessage( true );
        }
        if ( $language !== null ) {
            $oldLang = $popts->setTargetLanguage( $language );
        }

        $parserOutput = $wgParser->getFreshParser()->parse(
            $text, $this->getTitle(), $popts,
            $linestart, true, $this->mRevisionId
        );

        if ( $interface ) {
            $popts->setInterfaceMessage( false );
        }
        if ( $language !== null ) {
            $popts->setTargetLanguage( $oldLang );
        }

        return $parserOutput->getText();
    }

    public function parseInline( $text, $linestart = true, $interface = false ) {
        $parsed = $this->parse( $text, $linestart, $interface );
        return Parser::stripOuterParagraph( $parsed );
    }

    public function setSquidMaxage( $maxage ) {
        $this->mSquidMaxage = $maxage;
    }

    public function enableClientCache( $state ) {
        return wfSetVar( $this->mEnableClientCache, $state );
    }

    function getCacheVaryCookies() {
        static $cookies;
        if ( $cookies === null ) {
            $config = $this->getConfig();
            $cookies = array_merge(
                array(
                    $config->get( 'CookiePrefix' ) . 'Token',
                    $config->get( 'CookiePrefix' ) . 'LoggedOut',
                    "forceHTTPS",
                    session_name()
                ),
                $config->get( 'CacheVaryCookies' )
            );
            wfRunHooks( 'GetCacheVaryCookies', array( $this, &$cookies ) );
        }
        return $cookies;
    }

    function haveCacheVaryCookies() {
        $cookieHeader = $this->getRequest()->getHeader( 'cookie' );
        if ( $cookieHeader === false ) {
            return false;
        }
        $cvCookies = $this->getCacheVaryCookies();
        foreach ( $cvCookies as $cookieName ) {
            # Check for a simple string match, like the way squid does it
            if ( strpos( $cookieHeader, $cookieName ) !== false ) {
                wfDebug( __METHOD__ . ": found $cookieName\n" );
                return true;
            }
        }
        wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
        return false;
    }

    public function addVaryHeader( $header, $option = null ) {
        if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
            $this->mVaryHeader[$header] = (array)$option;
        } elseif ( is_array( $option ) ) {
            if ( is_array( $this->mVaryHeader[$header] ) ) {
                $this->mVaryHeader[$header] = array_merge( $this->mVaryHeader[$header], $option );
            } else {
                $this->mVaryHeader[$header] = $option;
            }
        }
        $this->mVaryHeader[$header] = array_unique( (array)$this->mVaryHeader[$header] );
    }

    public function getVaryHeader() {
        return 'Vary: ' . join( ', ', array_keys( $this->mVaryHeader ) );
    }

    public function getXVO() {
        $cvCookies = $this->getCacheVaryCookies();

        $cookiesOption = array();
        foreach ( $cvCookies as $cookieName ) {
            $cookiesOption[] = 'string-contains=' . $cookieName;
        }
        $this->addVaryHeader( 'Cookie', $cookiesOption );

        $headers = array();
        foreach ( $this->mVaryHeader as $header => $option ) {
            $newheader = $header;
            if ( is_array( $option ) && count( $option ) > 0 ) {
                $newheader .= ';' . implode( ';', $option );
            }
            $headers[] = $newheader;
        }
        $xvo = 'X-Vary-Options: ' . implode( ',', $headers );

        return $xvo;
    }

    function addAcceptLanguage() {
        $title = $this->getTitle();
        if ( !$title instanceof Title ) {
            return;
        }

        $lang = $title->getPageLanguage();
        if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
            $variants = $lang->getVariants();
            $aloption = array();
            foreach ( $variants as $variant ) {
                if ( $variant === $lang->getCode() ) {
                    continue;
                } else {
                    $aloption[] = 'string-contains=' . $variant;

                    // IE and some other browsers use BCP 47 standards in
                    // their Accept-Language header, like "zh-CN" or "zh-Hant".
                    // We should handle these too.
                    $variantBCP47 = wfBCP47( $variant );
                    if ( $variantBCP47 !== $variant ) {
                        $aloption[] = 'string-contains=' . $variantBCP47;
                    }
                }
            }
            $this->addVaryHeader( 'Accept-Language', $aloption );
        }
    }

    public function preventClickjacking( $enable = true ) {
        $this->mPreventClickjacking = $enable;
    }

    public function allowClickjacking() {
        $this->mPreventClickjacking = false;
    }

    public function getPreventClickjacking() {
        return $this->mPreventClickjacking;
    }

    public function getFrameOptions() {
        $config = $this->getConfig();
        if ( $config->get( 'BreakFrames' ) ) {
            return 'DENY';
        } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
            return $config->get( 'EditPageFrameOptions' );
        }
        return false;
    }

    public function sendCacheControl() {
        $response = $this->getRequest()->response();
        $config = $this->getConfig();
        if ( $config->get( 'UseETag' ) && $this->mETag ) {
            $response->header( "ETag: $this->mETag" );
        }

        $this->addVaryHeader( 'Cookie' );
        $this->addAcceptLanguage();

        # don't serve compressed data to clients who can't handle it
        # maintain different caches for logged-in users and non-logged in ones
        $response->header( $this->getVaryHeader() );

        if ( $config->get( 'UseXVO' ) ) {
            # Add an X-Vary-Options header for Squid with Wikimedia patches
            $response->header( $this->getXVO() );
        }

        if ( $this->mEnableClientCache ) {
            if (
                $config->get( 'UseSquid' ) && session_id() == '' && !$this->isPrintable() &&
                $this->mSquidMaxage != 0 && !$this->haveCacheVaryCookies()
            ) {
                if ( $config->get( 'UseESI' ) ) {
                    # We'll purge the proxy cache explicitly, but require end user agents
                    # to revalidate against the proxy on each visit.
                    # Surrogate-Control controls our Squid, Cache-Control downstream caches
                    wfDebug( __METHOD__ . ": proxy caching with ESI; {$this->mLastModified} **\n", 'log' );
                    # start with a shorter timeout for initial testing
                    # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
                    $response->header( 'Surrogate-Control: max-age=' . $config->get( 'SquidMaxage' )
                        . '+' . $this->mSquidMaxage . ', content="ESI/1.0"' );
                    $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
                } else {
                    # We'll purge the proxy cache for anons explicitly, but require end user agents
                    # to revalidate against the proxy on each visit.
                    # IMPORTANT! The Squid needs to replace the Cache-Control header with
                    # Cache-Control: s-maxage=0, must-revalidate, max-age=0
                    wfDebug( __METHOD__ . ": local proxy caching; {$this->mLastModified} **\n", 'log' );
                    # start with a shorter timeout for initial testing
                    # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
                    $response->header( 'Cache-Control: s-maxage=' . $this->mSquidMaxage
                        . ', must-revalidate, max-age=0' );
                }
            } else {
                # We do want clients to cache if they can, but they *must* check for updates
                # on revisiting the page.
                wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **\n", 'log' );
                $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
                $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
            }
            if ( $this->mLastModified ) {
                $response->header( "Last-Modified: {$this->mLastModified}" );
            }
        } else {
            wfDebug( __METHOD__ . ": no caching **\n", 'log' );

            # In general, the absence of a last modified header should be enough to prevent
            # the client from using its cache. We send a few other things just to make sure.
            $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
            $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
            $response->header( 'Pragma: no-cache' );
        }
    }

    public function output() {
        global $wgLanguageCode;

        if ( $this->mDoNothing ) {
            return;
        }

        wfProfileIn( __METHOD__ );

        $response = $this->getRequest()->response();
        $config = $this->getConfig();

        if ( $this->mRedirect != '' ) {
            # Standards require redirect URLs to be absolute
            $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );

            $redirect = $this->mRedirect;
            $code = $this->mRedirectCode;

            if ( wfRunHooks( "BeforePageRedirect", array( $this, &$redirect, &$code ) ) ) {
                if ( $code == '301' || $code == '303' ) {
                    if ( !$config->get( 'DebugRedirects' ) ) {
                        $message = HttpStatus::getMessage( $code );
                        $response->header( "HTTP/1.1 $code $message" );
                    }
                    $this->mLastModified = wfTimestamp( TS_RFC2822 );
                }
                if ( $config->get( 'VaryOnXFP' ) ) {
                    $this->addVaryHeader( 'X-Forwarded-Proto' );
                }
                $this->sendCacheControl();

                $response->header( "Content-Type: text/html; charset=utf-8" );
                if ( $config->get( 'DebugRedirects' ) ) {
                    $url = htmlspecialchars( $redirect );
                    print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
                    print "<p>Location: <a href=\"$url\">$url</a></p>\n";
                    print "</body>\n</html>\n";
                } else {
                    $response->header( 'Location: ' . $redirect );
                }
            }

            wfProfileOut( __METHOD__ );
            return;
        } elseif ( $this->mStatusCode ) {
            $message = HttpStatus::getMessage( $this->mStatusCode );
            if ( $message ) {
                $response->header( 'HTTP/1.1 ' . $this->mStatusCode . ' ' . $message );
            }
        }

        # Buffer output; final headers may depend on later processing
        ob_start();

        $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
        $response->header( 'Content-language: ' . $wgLanguageCode );

        // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
        // jQuery etc. can work correctly.
        $response->header( 'X-UA-Compatible: IE=Edge' );

        // Prevent framing, if requested
        $frameOptions = $this->getFrameOptions();
        if ( $frameOptions ) {
            $response->header( "X-Frame-Options: $frameOptions" );
        }

        if ( $this->mArticleBodyOnly ) {
            echo $this->mBodytext;
        } else {

            $sk = $this->getSkin();
            // add skin specific modules
            $modules = $sk->getDefaultModules();

            // enforce various default modules for all skins
            $coreModules = array(
                // keep this list as small as possible
                'mediawiki.page.startup',
                'mediawiki.user',
            );

            // Support for high-density display images if enabled
            if ( $config->get( 'ResponsiveImages' ) ) {
                $coreModules[] = 'mediawiki.hidpi';
            }

            $this->addModules( $coreModules );
            foreach ( $modules as $group ) {
                $this->addModules( $group );
            }
            MWDebug::addModules( $this );

            // Hook that allows last minute changes to the output page, e.g.
            // adding of CSS or Javascript by extensions.
            wfRunHooks( 'BeforePageDisplay', array( &$this, &$sk ) );

            wfProfileIn( 'Output-skin' );
            $sk->outputPage();
            wfProfileOut( 'Output-skin' );
        }

        // This hook allows last minute changes to final overall output by modifying output buffer
        wfRunHooks( 'AfterFinalPageOutput', array( $this ) );

        $this->sendCacheControl();

        ob_end_flush();

        wfProfileOut( __METHOD__ );
    }

    public function out( $ins ) {
        wfDeprecated( __METHOD__, '1.22' );
        print $ins;
    }

    function blockedPage() {
        throw new UserBlockedError( $this->getUser()->mBlock );
    }

    public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
        $this->setPageTitle( $pageTitle );
        if ( $htmlTitle !== false ) {
            $this->setHTMLTitle( $htmlTitle );
        }
        $this->setRobotPolicy( 'noindex,nofollow' );
        $this->setArticleRelated( false );
        $this->enableClientCache( false );
        $this->mRedirect = '';
        $this->clearSubtitle();
        $this->clearHTML();
    }

    public function showErrorPage( $title, $msg, $params = array() ) {
        if ( !$title instanceof Message ) {
            $title = $this->msg( $title );
        }

        $this->prepareErrorPage( $title );

        if ( $msg instanceof Message ) {
            if ( $params !== array() ) {
                trigger_error( 'Argument ignored: $params. The message parameters argument '
                    . 'is discarded when the $msg argument is a Message object instead of '
                    . 'a string.', E_USER_NOTICE );
            }
            $this->addHTML( $msg->parseAsBlock() );
        } else {
            $this->addWikiMsgArray( $msg, $params );
        }

        $this->returnToMain();
    }

    public function showPermissionsErrorPage( array $errors, $action = null ) {
        // For some action (read, edit, create and upload), display a "login to do this action"
        // error if all of the following conditions are met:
        // 1. the user is not logged in
        // 2. the only error is insufficient permissions (i.e. no block or something else)
        // 3. the error can be avoided simply by logging in
        if ( in_array( $action, array( 'read', 'edit', 'createpage', 'createtalk', 'upload' ) )
            && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
            && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
            && ( User::groupHasPermission( 'user', $action )
            || User::groupHasPermission( 'autoconfirmed', $action ) )
        ) {
            $displayReturnto = null;

            # Due to bug 32276, if a user does not have read permissions,
            # $this->getTitle() will just give Special:Badtitle, which is
            # not especially useful as a returnto parameter. Use the title
            # from the request instead, if there was one.
            $request = $this->getRequest();
            $returnto = Title::newFromURL( $request->getVal( 'title', '' ) );
            if ( $action == 'edit' ) {
                $msg = 'whitelistedittext';
                $displayReturnto = $returnto;
            } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
                $msg = 'nocreatetext';
            } elseif ( $action == 'upload' ) {
                $msg = 'uploadnologintext';
            } else { # Read
                $msg = 'loginreqpagetext';
                $displayReturnto = Title::newMainPage();
            }

            $query = array();

            if ( $returnto ) {
                $query['returnto'] = $returnto->getPrefixedText();

                if ( !$request->wasPosted() ) {
                    $returntoquery = $request->getValues();
                    unset( $returntoquery['title'] );
                    unset( $returntoquery['returnto'] );
                    unset( $returntoquery['returntoquery'] );
                    $query['returntoquery'] = wfArrayToCgi( $returntoquery );
                }
            }
            $loginLink = Linker::linkKnown(
                SpecialPage::getTitleFor( 'Userlogin' ),
                $this->msg( 'loginreqlink' )->escaped(),
                array(),
                $query
            );

            $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
            $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );

            # Don't return to a page the user can't read otherwise
            # we'll end up in a pointless loop
            if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
                $this->returnToMain( null, $displayReturnto );
            }
        } else {
            $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
            $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
        }
    }

    public function versionRequired( $version ) {
        $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );

        $this->addWikiMsg( 'versionrequiredtext', $version );
        $this->returnToMain();
    }

    public function permissionRequired( $permission ) {
        throw new PermissionsError( $permission );
    }

    public function loginToUse() {
        throw new PermissionsError( 'read' );
    }

    public function formatPermissionsErrorMessage( array $errors, $action = null ) {
        if ( $action == null ) {
            $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
        } else {
            $action_desc = $this->msg( "action-$action" )->plain();
            $text = $this->msg(
                'permissionserrorstext-withaction',
                count( $errors ),
                $action_desc
            )->plain() . "\n\n";
        }

        if ( count( $errors ) > 1 ) {
            $text .= '<ul class="permissions-errors">' . "\n";

            foreach ( $errors as $error ) {
                $text .= '<li>';
                $text .= call_user_func_array( array( $this, 'msg' ), $error )->plain();
                $text .= "</li>\n";
            }
            $text .= '</ul>';
        } else {
            $text .= "<div class=\"permissions-errors\">\n" .
                    call_user_func_array( array( $this, 'msg' ), reset( $errors ) )->plain() .
                    "\n</div>";
        }

        return $text;
    }

    public function readOnlyPage( $source = null, $protected = false,
        array $reasons = array(), $action = null
    ) {
        $this->setRobotPolicy( 'noindex,nofollow' );
        $this->setArticleRelated( false );

        // If no reason is given, just supply a default "I can't let you do
        // that, Dave" message.  Should only occur if called by legacy code.
        if ( $protected && empty( $reasons ) ) {
            $reasons[] = array( 'badaccess-group0' );
        }

        if ( !empty( $reasons ) ) {
            // Permissions error
            if ( $source ) {
                $this->setPageTitle( $this->msg( 'viewsource-title', $this->getTitle()->getPrefixedText() ) );
                $this->addBacklinkSubtitle( $this->getTitle() );
            } else {
                $this->setPageTitle( $this->msg( 'badaccess' ) );
            }
            $this->addWikiText( $this->formatPermissionsErrorMessage( $reasons, $action ) );
        } else {
            // Wiki is read only
            throw new ReadOnlyError;
        }

        // Show source, if supplied
        if ( is_string( $source ) ) {
            $this->addWikiMsg( 'viewsourcetext' );

            $pageLang = $this->getTitle()->getPageLanguage();
            $params = array(
                'id' => 'wpTextbox1',
                'name' => 'wpTextbox1',
                'cols' => $this->getUser()->getOption( 'cols' ),
                'rows' => $this->getUser()->getOption( 'rows' ),
                'readonly' => 'readonly',
                'lang' => $pageLang->getHtmlCode(),
                'dir' => $pageLang->getDir(),
            );
            $this->addHTML( Html::element( 'textarea', $params, $source ) );

            // Show templates used by this article
            $templates = Linker::formatTemplates( $this->getTitle()->getTemplateLinksFrom() );
            $this->addHTML( "<div class='templatesUsed'>
$templates
</div>
" );
        }

        # If the title doesn't exist, it's fairly pointless to print a return
        # link to it.  After all, you just tried editing it and couldn't, so
        # what's there to do there?
        if ( $this->getTitle()->exists() ) {
            $this->returnToMain( null, $this->getTitle() );
        }
    }

    public function rateLimited() {
        throw new ThrottledError;
    }

    public function showLagWarning( $lag ) {
        $config = $this->getConfig();
        if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
            $message = $lag < $config->get( 'SlaveLagCritical' )
                ? 'lag-warn-normal'
                : 'lag-warn-high';
            $wrap = Html::rawElement( 'div', array( 'class' => "mw-{$message}" ), "\n$1\n" );
            $this->wrapWikiMsg( "$wrap\n", array( $message, $this->getLanguage()->formatNum( $lag ) ) );
        }
    }

    public function showFatalError( $message ) {
        $this->prepareErrorPage( $this->msg( 'internalerror' ) );

        $this->addHTML( $message );
    }

    public function showUnexpectedValueError( $name, $val ) {
        $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
    }

    public function showFileCopyError( $old, $new ) {
        $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
    }

    public function showFileRenameError( $old, $new ) {
        $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
    }

    public function showFileDeleteError( $name ) {
        $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
    }

    public function showFileNotFoundError( $name ) {
        $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
    }

    public function addReturnTo( $title, array $query = array(), $text = null, $options = array() ) {
        $link = $this->msg( 'returnto' )->rawParams(
            Linker::link( $title, $text, array(), $query, $options ) )->escaped();
        $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
    }

    public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
        if ( $returnto == null ) {
            $returnto = $this->getRequest()->getText( 'returnto' );
        }

        if ( $returntoquery == null ) {
            $returntoquery = $this->getRequest()->getText( 'returntoquery' );
        }

        if ( $returnto === '' ) {
            $returnto = Title::newMainPage();
        }

        if ( is_object( $returnto ) ) {
            $titleObj = $returnto;
        } else {
            $titleObj = Title::newFromText( $returnto );
        }
        if ( !is_object( $titleObj ) ) {
            $titleObj = Title::newMainPage();
        }

        $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
    }

    public function headElement( Skin $sk, $includeStyle = true ) {
        global $wgContLang;

        $userdir = $this->getLanguage()->getDir();
        $sitedir = $wgContLang->getDir();

        $ret = Html::htmlHeader( $sk->getHtmlElementAttributes() );

        if ( $this->getHTMLTitle() == '' ) {
            $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
        }

        $openHead = Html::openElement( 'head' );
        if ( $openHead ) {
            # Don't bother with the newline if $head == ''
            $ret .= "$openHead\n";
        }

        if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
            // Add <meta charset="UTF-8">
            // This should be before <title> since it defines the charset used by
            // text including the text inside <title>.
            // The spec recommends defining XHTML5's charset using the XML declaration
            // instead of meta.
            // Our XML declaration is output by Html::htmlHeader.
            // http://www.whatwg.org/html/semantics.html#attr-meta-http-equiv-content-type
            // http://www.whatwg.org/html/semantics.html#charset
            $ret .= Html::element( 'meta', array( 'charset' => 'UTF-8' ) ) . "\n";
        }

        $ret .= Html::element( 'title', null, $this->getHTMLTitle() ) . "\n";

        foreach ( $this->getHeadLinksArray() as $item ) {
            $ret .= $item . "\n";
        }

        // No newline after buildCssLinks since makeResourceLoaderLink did that already
        $ret .= $this->buildCssLinks();

        $ret .= $this->getHeadScripts() . "\n";

        foreach ( $this->mHeadItems as $item ) {
            $ret .= $item . "\n";
        }

        $closeHead = Html::closeElement( 'head' );
        if ( $closeHead ) {
            $ret .= "$closeHead\n";
        }

        $bodyClasses = array();
        $bodyClasses[] = 'mediawiki';

        # Classes for LTR/RTL directionality support
        $bodyClasses[] = $userdir;
        $bodyClasses[] = "sitedir-$sitedir";

        if ( $this->getLanguage()->capitalizeAllNouns() ) {
            # A <body> class is probably not the best way to do this . . .
            $bodyClasses[] = 'capitalize-all-nouns';
        }

        $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
        $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
        $bodyClasses[] =
            'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );

        $bodyAttrs = array();
        // While the implode() is not strictly needed, it's used for backwards compatibility
        // (this used to be built as a string and hooks likely still expect that).
        $bodyAttrs['class'] = implode( ' ', $bodyClasses );

        // Allow skins and extensions to add body attributes they need
        $sk->addToBodyAttributes( $this, $bodyAttrs );
        wfRunHooks( 'OutputPageBodyAttributes', array( $this, $sk, &$bodyAttrs ) );

        $ret .= Html::openElement( 'body', $bodyAttrs ) . "\n";

        return $ret;
    }

    public function getResourceLoader() {
        if ( is_null( $this->mResourceLoader ) ) {
            $this->mResourceLoader = new ResourceLoader( $this->getConfig() );
        }
        return $this->mResourceLoader;
    }

    protected function makeResourceLoaderLink( $modules, $only, $useESI = false,
        array $extraQuery = array(), $loadCall = false
    ) {
        $modules = (array)$modules;

        $links = array(
            'html' => '',
            'states' => array(),
        );

        if ( !count( $modules ) ) {
            return $links;
        }

        if ( count( $modules ) > 1 ) {
            // Remove duplicate module requests
            $modules = array_unique( $modules );
            // Sort module names so requests are more uniform
            sort( $modules );

            if ( ResourceLoader::inDebugMode() ) {
                // Recursively call us for every item
                foreach ( $modules as $name ) {
                    $link = $this->makeResourceLoaderLink( $name, $only, $useESI );
                    $links['html'] .= $link['html'];
                    $links['states'] += $link['states'];
                }
                return $links;
            }
        }

        if ( !is_null( $this->mTarget ) ) {
            $extraQuery['target'] = $this->mTarget;
        }

        // Create keyed-by-source and then keyed-by-group list of module objects from modules list
        $sortedModules = array();
        $resourceLoader = $this->getResourceLoader();
        $resourceLoaderUseESI = $this->getConfig()->get( 'ResourceLoaderUseESI' );
        foreach ( $modules as $name ) {
            $module = $resourceLoader->getModule( $name );
            # Check that we're allowed to include this module on this page
            if ( !$module
                || ( $module->getOrigin() > $this->getAllowedModules( ResourceLoaderModule::TYPE_SCRIPTS )
                    && $only == ResourceLoaderModule::TYPE_SCRIPTS )
                || ( $module->getOrigin() > $this->getAllowedModules( ResourceLoaderModule::TYPE_STYLES )
                    && $only == ResourceLoaderModule::TYPE_STYLES )
                || ( $module->getOrigin() > $this->getAllowedModules( ResourceLoaderModule::TYPE_COMBINED )
                    && $only == ResourceLoaderModule::TYPE_COMBINED )
                || ( $this->mTarget && !in_array( $this->mTarget, $module->getTargets() ) )
            ) {
                continue;
            }

            $sortedModules[$module->getSource()][$module->getGroup()][$name] = $module;
        }

        foreach ( $sortedModules as $source => $groups ) {
            foreach ( $groups as $group => $grpModules ) {
                // Special handling for user-specific groups
                $user = null;
                if ( ( $group === 'user' || $group === 'private' ) && $this->getUser()->isLoggedIn() ) {
                    $user = $this->getUser()->getName();
                }

                // Create a fake request based on the one we are about to make so modules return
                // correct timestamp and emptiness data
                $query = ResourceLoader::makeLoaderQuery(
                    array(), // modules; not determined yet
                    $this->getLanguage()->getCode(),
                    $this->getSkin()->getSkinName(),
                    $user,
                    null, // version; not determined yet
                    ResourceLoader::inDebugMode(),
                    $only === ResourceLoaderModule::TYPE_COMBINED ? null : $only,
                    $this->isPrintable(),
                    $this->getRequest()->getBool( 'handheld' ),
                    $extraQuery
                );
                $context = new ResourceLoaderContext( $resourceLoader, new FauxRequest( $query ) );


                // Extract modules that know they're empty and see if we have one or more
                // raw modules
                $isRaw = false;
                foreach ( $grpModules as $key => $module ) {
                    // Inline empty modules: since they're empty, just mark them as 'ready' (bug 46857)
                    // If we're only getting the styles, we don't need to do anything for empty modules.
                    if ( $module->isKnownEmpty( $context ) ) {
                        unset( $grpModules[$key] );
                        if ( $only !== ResourceLoaderModule::TYPE_STYLES ) {
                            $links['states'][$key] = 'ready';
                        }
                    }

                    $isRaw |= $module->isRaw();
                }

                // If there are no non-empty modules, skip this group
                if ( count( $grpModules ) === 0 ) {
                    continue;
                }

                // Inline private modules. These can't be loaded through load.php for security
                // reasons, see bug 34907. Note that these modules should be loaded from
                // getHeadScripts() before the first loader call. Otherwise other modules can't
                // properly use them as dependencies (bug 30914)
                if ( $group === 'private' ) {
                    if ( $only == ResourceLoaderModule::TYPE_STYLES ) {
                        $links['html'] .= Html::inlineStyle(
                            $resourceLoader->makeModuleResponse( $context, $grpModules )
                        );
                    } else {
                        $links['html'] .= Html::inlineScript(
                            ResourceLoader::makeLoaderConditionalScript(
                                $resourceLoader->makeModuleResponse( $context, $grpModules )
                            )
                        );
                    }
                    $links['html'] .= "\n";
                    continue;
                }

                // Special handling for the user group; because users might change their stuff
                // on-wiki like user pages, or user preferences; we need to find the highest
                // timestamp of these user-changeable modules so we can ensure cache misses on change
                // This should NOT be done for the site group (bug 27564) because anons get that too
                // and we shouldn't be putting timestamps in Squid-cached HTML
                $version = null;
                if ( $group === 'user' ) {
                    // Get the maximum timestamp
                    $timestamp = 1;
                    foreach ( $grpModules as $module ) {
                        $timestamp = max( $timestamp, $module->getModifiedTime( $context ) );
                    }
                    // Add a version parameter so cache will break when things change
                    $query['version'] = wfTimestamp( TS_ISO_8601_BASIC, $timestamp );
                }

                $query['modules'] = ResourceLoader::makePackedModulesString( array_keys( $grpModules ) );
                $moduleContext = new ResourceLoaderContext( $resourceLoader, new FauxRequest( $query ) );
                $url = $resourceLoader->createLoaderURL( $source, $moduleContext, $extraQuery );

                if ( $useESI && $resourceLoaderUseESI ) {
                    $esi = Xml::element( 'esi:include', array( 'src' => $url ) );
                    if ( $only == ResourceLoaderModule::TYPE_STYLES ) {
                        $link = Html::inlineStyle( $esi );
                    } else {
                        $link = Html::inlineScript( $esi );
                    }
                } else {
                    // Automatically select style/script elements
                    if ( $only === ResourceLoaderModule::TYPE_STYLES ) {
                        $link = Html::linkedStyle( $url );
                    } elseif ( $loadCall ) {
                        $link = Html::inlineScript(
                            ResourceLoader::makeLoaderConditionalScript(
                                Xml::encodeJsCall( 'mw.loader.load', array( $url, 'text/javascript', true ) )
                            )
                        );
                    } else {
                        $link = Html::linkedScript( $url );
                        if ( $context->getOnly() === 'scripts' && !$context->getRaw() && !$isRaw ) {
                            // Wrap only=script requests in a conditional as browsers not supported
                            // by the startup module would unconditionally execute this module.
                            // Otherwise users will get "ReferenceError: mw is undefined" or
                            // "jQuery is undefined" from e.g. a "site" module.
                            $link = Html::inlineScript(
                                ResourceLoader::makeLoaderConditionalScript(
                                    Xml::encodeJsCall( 'document.write', array( $link ) )
                                )
                            );
                        }

                        // For modules requested directly in the html via <link> or <script>,
                        // tell mw.loader they are being loading to prevent duplicate requests.
                        foreach ( $grpModules as $key => $module ) {
                            // Don't output state=loading for the startup module..
                            if ( $key !== 'startup' ) {
                                $links['states'][$key] = 'loading';
                            }
                        }
                    }
                }

                if ( $group == 'noscript' ) {
                    $links['html'] .= Html::rawElement( 'noscript', array(), $link ) . "\n";
                } else {
                    $links['html'] .= $link . "\n";
                }
            }
        }

        return $links;
    }

    protected static function getHtmlFromLoaderLinks( array $links ) {
        $html = '';
        $states = array();
        foreach ( $links as $link ) {
            if ( !is_array( $link ) ) {
                $html .= $link;
            } else {
                $html .= $link['html'];
                $states += $link['states'];
            }
        }

        if ( count( $states ) ) {
            $html = Html::inlineScript(
                ResourceLoader::makeLoaderConditionalScript(
                    ResourceLoader::makeLoaderStateScript( $states )
                )
            ) . "\n" . $html;
        }

        return $html;
    }

    function getHeadScripts() {
        // Startup - this will immediately load jquery and mediawiki modules
        $links = array();
        $links[] = $this->makeResourceLoaderLink( 'startup', ResourceLoaderModule::TYPE_SCRIPTS, true );

        // Load config before anything else
        $links[] = Html::inlineScript(
            ResourceLoader::makeLoaderConditionalScript(
                ResourceLoader::makeConfigSetScript( $this->getJSVars() )
            )
        );

        // Load embeddable private modules before any loader links
        // This needs to be TYPE_COMBINED so these modules are properly wrapped
        // in mw.loader.implement() calls and deferred until mw.user is available
        $embedScripts = array( 'user.options', 'user.tokens' );
        $links[] = $this->makeResourceLoaderLink( $embedScripts, ResourceLoaderModule::TYPE_COMBINED );

        // Scripts and messages "only" requests marked for top inclusion
        // Messages should go first
        $links[] = $this->makeResourceLoaderLink(
            $this->getModuleMessages( true, 'top' ),
            ResourceLoaderModule::TYPE_MESSAGES
        );
        $links[] = $this->makeResourceLoaderLink(
            $this->getModuleScripts( true, 'top' ),
            ResourceLoaderModule::TYPE_SCRIPTS
        );

        // Modules requests - let the client calculate dependencies and batch requests as it likes
        // Only load modules that have marked themselves for loading at the top
        $modules = $this->getModules( true, 'top' );
        if ( $modules ) {
            $links[] = Html::inlineScript(
                ResourceLoader::makeLoaderConditionalScript(
                    Xml::encodeJsCall( 'mw.loader.load', array( $modules ) )
                )
            );
        }

        if ( $this->getConfig()->get( 'ResourceLoaderExperimentalAsyncLoading' ) ) {
            $links[] = $this->getScriptsForBottomQueue( true );
        }

        return self::getHtmlFromLoaderLinks( $links );
    }

    function getScriptsForBottomQueue( $inHead ) {
        // Scripts and messages "only" requests marked for bottom inclusion
        // If we're in the <head>, use load() calls rather than <script src="..."> tags
        // Messages should go first
        $links = array();
        $links[] = $this->makeResourceLoaderLink( $this->getModuleMessages( true, 'bottom' ),
            ResourceLoaderModule::TYPE_MESSAGES, /* $useESI = */ false, /* $extraQuery = */ array(),
            /* $loadCall = */ $inHead
        );
        $links[] = $this->makeResourceLoaderLink( $this->getModuleScripts( true, 'bottom' ),
            ResourceLoaderModule::TYPE_SCRIPTS, /* $useESI = */ false, /* $extraQuery = */ array(),
            /* $loadCall = */ $inHead
        );

        // Modules requests - let the client calculate dependencies and batch requests as it likes
        // Only load modules that have marked themselves for loading at the bottom
        $modules = $this->getModules( true, 'bottom' );
        if ( $modules ) {
            $links[] = Html::inlineScript(
                ResourceLoader::makeLoaderConditionalScript(
                    Xml::encodeJsCall( 'mw.loader.load', array( $modules, null, true ) )
                )
            );
        }

        // Legacy Scripts
        $links[] = "\n" . $this->mScripts;

        // Add site JS if enabled
        $links[] = $this->makeResourceLoaderLink( 'site', ResourceLoaderModule::TYPE_SCRIPTS,
            /* $useESI = */ false, /* $extraQuery = */ array(), /* $loadCall = */ $inHead
        );

        // Add user JS if enabled
        if ( $this->getConfig()->get( 'AllowUserJs' )
            && $this->getUser()->isLoggedIn()
            && $this->getTitle()
            && $this->getTitle()->isJsSubpage()
            && $this->userCanPreview()
        ) {
            # XXX: additional security check/prompt?
            // We're on a preview of a JS subpage
            // Exclude this page from the user module in case it's in there (bug 26283)
            $links[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_SCRIPTS, false,
                array( 'excludepage' => $this->getTitle()->getPrefixedDBkey() ), $inHead
            );
            // Load the previewed JS
            $links[] = Html::inlineScript( "\n"
                    . $this->getRequest()->getText( 'wpTextbox1' ) . "\n" ) . "\n";

            // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
            // asynchronously and may arrive *after* the inline script here. So the previewed code
            // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js...
        } else {
            // Include the user module normally, i.e., raw to avoid it being wrapped in a closure.
            $links[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_SCRIPTS,
                /* $useESI = */ false, /* $extraQuery = */ array(), /* $loadCall = */ $inHead
            );
        }

        // Group JS is only enabled if site JS is enabled.
        $links[] = $this->makeResourceLoaderLink( 'user.groups', ResourceLoaderModule::TYPE_COMBINED,
            /* $useESI = */ false, /* $extraQuery = */ array(), /* $loadCall = */ $inHead
        );

        return self::getHtmlFromLoaderLinks( $links );
    }

    function getBottomScripts() {
        // Optimise jQuery ready event cross-browser.
        // This also enforces $.isReady to be true at </body> which fixes the
        // mw.loader bug in Firefox with using document.write between </body>
        // and the DOMContentReady event (bug 47457).
        $html = Html::inlineScript( 'window.jQuery && jQuery.ready();' );

        if ( !$this->getConfig()->get( 'ResourceLoaderExperimentalAsyncLoading' ) ) {
            $html .= $this->getScriptsForBottomQueue( false );
        }

        return $html;
    }

    public function getJsConfigVars() {
        return $this->mJsConfigVars;
    }

    public function addJsConfigVars( $keys, $value = null ) {
        if ( is_array( $keys ) ) {
            foreach ( $keys as $key => $value ) {
                $this->mJsConfigVars[$key] = $value;
            }
            return;
        }

        $this->mJsConfigVars[$keys] = $value;
    }

    private function getJSVars() {
        global $wgContLang;

        $curRevisionId = 0;
        $articleId = 0;
        $canonicalSpecialPageName = false; # bug 21115

        $title = $this->getTitle();
        $ns = $title->getNamespace();
        $canonicalNamespace = MWNamespace::exists( $ns )
            ? MWNamespace::getCanonicalName( $ns )
            : $title->getNsText();

        $sk = $this->getSkin();
        // Get the relevant title so that AJAX features can use the correct page name
        // when making API requests from certain special pages (bug 34972).
        $relevantTitle = $sk->getRelevantTitle();
        $relevantUser = $sk->getRelevantUser();

        if ( $ns == NS_SPECIAL ) {
            list( $canonicalSpecialPageName, /*...*/ ) =
                SpecialPageFactory::resolveAlias( $title->getDBkey() );
        } elseif ( $this->canUseWikiPage() ) {
            $wikiPage = $this->getWikiPage();
            $curRevisionId = $wikiPage->getLatest();
            $articleId = $wikiPage->getId();
        }

        $lang = $title->getPageLanguage();

        // Pre-process information
        $separatorTransTable = $lang->separatorTransformTable();
        $separatorTransTable = $separatorTransTable ? $separatorTransTable : array();
        $compactSeparatorTransTable = array(
            implode( "\t", array_keys( $separatorTransTable ) ),
            implode( "\t", $separatorTransTable ),
        );
        $digitTransTable = $lang->digitTransformTable();
        $digitTransTable = $digitTransTable ? $digitTransTable : array();
        $compactDigitTransTable = array(
            implode( "\t", array_keys( $digitTransTable ) ),
            implode( "\t", $digitTransTable ),
        );

        $user = $this->getUser();

        $vars = array(
            'wgCanonicalNamespace' => $canonicalNamespace,
            'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
            'wgNamespaceNumber' => $title->getNamespace(),
            'wgPageName' => $title->getPrefixedDBkey(),
            'wgTitle' => $title->getText(),
            'wgCurRevisionId' => $curRevisionId,
            'wgRevisionId' => (int)$this->getRevisionId(),
            'wgArticleId' => $articleId,
            'wgIsArticle' => $this->isArticle(),
            'wgIsRedirect' => $title->isRedirect(),
            'wgAction' => Action::getActionName( $this->getContext() ),
            'wgUserName' => $user->isAnon() ? null : $user->getName(),
            'wgUserGroups' => $user->getEffectiveGroups(),
            'wgCategories' => $this->getCategories(),
            'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
            'wgPageContentLanguage' => $lang->getCode(),
            'wgPageContentModel' => $title->getContentModel(),
            'wgSeparatorTransformTable' => $compactSeparatorTransTable,
            'wgDigitTransformTable' => $compactDigitTransTable,
            'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
            'wgMonthNames' => $lang->getMonthNamesArray(),
            'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
            'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
        );

        if ( $user->isLoggedIn() ) {
            $vars['wgUserId'] = $user->getId();
            $vars['wgUserEditCount'] = $user->getEditCount();
            $userReg = wfTimestampOrNull( TS_UNIX, $user->getRegistration() );
            $vars['wgUserRegistration'] = $userReg !== null ? ( $userReg * 1000 ) : null;
            // Get the revision ID of the oldest new message on the user's talk
            // page. This can be used for constructing new message alerts on
            // the client side.
            $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
        }

        if ( $wgContLang->hasVariants() ) {
            $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
        }
        // Same test as SkinTemplate
        $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
            && ( $title->exists() || $title->quickUserCan( 'create', $user ) );

        foreach ( $title->getRestrictionTypes() as $type ) {
            $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
        }

        if ( $title->isMainPage() ) {
            $vars['wgIsMainPage'] = true;
        }

        if ( $this->mRedirectedFrom ) {
            $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
        }

        if ( $relevantUser ) {
            $vars['wgRelevantUserName'] = $relevantUser->getName();
        }

        // Allow extensions to add their custom variables to the mw.config map.
        // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
        // page-dependant but site-wide (without state).
        // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
        wfRunHooks( 'MakeGlobalVariablesScript', array( &$vars, $this ) );

        // Merge in variables from addJsConfigVars last
        return array_merge( $vars, $this->getJsConfigVars() );
    }

    public function userCanPreview() {
        if ( $this->getRequest()->getVal( 'action' ) != 'submit'
            || !$this->getRequest()->wasPosted()
            || !$this->getUser()->matchEditToken(
                $this->getRequest()->getVal( 'wpEditToken' ) )
        ) {
            return false;
        }
        if ( !$this->getTitle()->isJsSubpage() && !$this->getTitle()->isCssSubpage() ) {
            return false;
        }

        return !count( $this->getTitle()->getUserPermissionsErrors( 'edit', $this->getUser() ) );
    }

    public function getHeadLinksArray() {
        global $wgVersion;

        $tags = array();
        $config = $this->getConfig();

        $canonicalUrl = $this->mCanonicalUrl;

        $tags['meta-generator'] = Html::element( 'meta', array(
            'name' => 'generator',
            'content' => "MediaWiki $wgVersion",
        ) );

        $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
        if ( $p !== 'index,follow' ) {
            // http://www.robotstxt.org/wc/meta-user.html
            // Only show if it's different from the default robots policy
            $tags['meta-robots'] = Html::element( 'meta', array(
                'name' => 'robots',
                'content' => $p,
            ) );
        }

        foreach ( $this->mMetatags as $tag ) {
            if ( 0 == strcasecmp( 'http:', substr( $tag[0], 0, 5 ) ) ) {
                $a = 'http-equiv';
                $tag[0] = substr( $tag[0], 5 );
            } else {
                $a = 'name';
            }
            $tagName = "meta-{$tag[0]}";
            if ( isset( $tags[$tagName] ) ) {
                $tagName .= $tag[1];
            }
            $tags[$tagName] = Html::element( 'meta',
                array(
                    $a => $tag[0],
                    'content' => $tag[1]
                )
            );
        }

        foreach ( $this->mLinktags as $tag ) {
            $tags[] = Html::element( 'link', $tag );
        }

        # Universal edit button
        if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
            $user = $this->getUser();
            if ( $this->getTitle()->quickUserCan( 'edit', $user )
                && ( $this->getTitle()->exists() || $this->getTitle()->quickUserCan( 'create', $user ) ) ) {
                // Original UniversalEditButton
                $msg = $this->msg( 'edit' )->text();
                $tags['universal-edit-button'] = Html::element( 'link', array(
                    'rel' => 'alternate',
                    'type' => 'application/x-wiki',
                    'title' => $msg,
                    'href' => $this->getTitle()->getEditURL(),
                ) );
                // Alternate edit link
                $tags['alternative-edit'] = Html::element( 'link', array(
                    'rel' => 'edit',
                    'title' => $msg,
                    'href' => $this->getTitle()->getEditURL(),
                ) );
            }
        }

        # Generally the order of the favicon and apple-touch-icon links
        # should not matter, but Konqueror (3.5.9 at least) incorrectly
        # uses whichever one appears later in the HTML source. Make sure
        # apple-touch-icon is specified first to avoid this.
        if ( $config->get( 'AppleTouchIcon' ) !== false ) {
            $tags['apple-touch-icon'] = Html::element( 'link', array(
                'rel' => 'apple-touch-icon',
                'href' => $config->get( 'AppleTouchIcon' )
            ) );
        }

        if ( $config->get( 'Favicon' ) !== false ) {
            $tags['favicon'] = Html::element( 'link', array(
                'rel' => 'shortcut icon',
                'href' => $config->get( 'Favicon' )
            ) );
        }

        # OpenSearch description link
        $tags['opensearch'] = Html::element( 'link', array(
            'rel' => 'search',
            'type' => 'application/opensearchdescription+xml',
            'href' => wfScript( 'opensearch_desc' ),
            'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
        ) );

        if ( $config->get( 'EnableAPI' ) ) {
            # Real Simple Discovery link, provides auto-discovery information
            # for the MediaWiki API (and potentially additional custom API
            # support such as WordPress or Twitter-compatible APIs for a
            # blogging extension, etc)
            $tags['rsd'] = Html::element( 'link', array(
                'rel' => 'EditURI',
                'type' => 'application/rsd+xml',
                // Output a protocol-relative URL here if $wgServer is protocol-relative
                // Whether RSD accepts relative or protocol-relative URLs is completely undocumented, though
                'href' => wfExpandUrl( wfAppendQuery(
                    wfScript( 'api' ),
                    array( 'action' => 'rsd' ) ),
                    PROTO_RELATIVE
                ),
            ) );
        }

        # Language variants
        if ( !$config->get( 'DisableLangConversion' ) ) {
            $lang = $this->getTitle()->getPageLanguage();
            if ( $lang->hasVariants() ) {
                $variants = $lang->getVariants();
                foreach ( $variants as $_v ) {
                    $tags["variant-$_v"] = Html::element( 'link', array(
                        'rel' => 'alternate',
                        'hreflang' => wfBCP47( $_v ),
                        'href' => $this->getTitle()->getLocalURL( array( 'variant' => $_v ) ) )
                    );
                }
            }
            # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
            $tags["variant-x-default"] = Html::element( 'link', array(
                'rel' => 'alternate',
                'hreflang' => 'x-default',
                'href' => $this->getTitle()->getLocalURL() ) );
        }

        # Copyright
        $copyright = '';
        if ( $config->get( 'RightsPage' ) ) {
            $copy = Title::newFromText( $config->get( 'RightsPage' ) );

            if ( $copy ) {
                $copyright = $copy->getLocalURL();
            }
        }

        if ( !$copyright && $config->get( 'RightsUrl' ) ) {
            $copyright = $config->get( 'RightsUrl' );
        }

        if ( $copyright ) {
            $tags['copyright'] = Html::element( 'link', array(
                'rel' => 'copyright',
                'href' => $copyright )
            );
        }

        # Feeds
        if ( $config->get( 'Feed' ) ) {
            foreach ( $this->getSyndicationLinks() as $format => $link ) {
                # Use the page name for the title.  In principle, this could
                # lead to issues with having the same name for different feeds
                # corresponding to the same page, but we can't avoid that at
                # this low a level.

                $tags[] = $this->feedLink(
                    $format,
                    $link,
                    # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
                    $this->msg( "page-{$format}-feed", $this->getTitle()->getPrefixedText() )->text()
                );
            }

            # Recent changes feed should appear on every page (except recentchanges,
            # that would be redundant). Put it after the per-page feed to avoid
            # changing existing behavior. It's still available, probably via a
            # menu in your browser. Some sites might have a different feed they'd
            # like to promote instead of the RC feed (maybe like a "Recent New Articles"
            # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
            # If so, use it instead.
            $sitename = $config->get( 'Sitename' );
            if ( $config->get( 'OverrideSiteFeed' ) ) {
                foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
                    // Note, this->feedLink escapes the url.
                    $tags[] = $this->feedLink(
                        $type,
                        $feedUrl,
                        $this->msg( "site-{$type}-feed", $sitename )->text()
                    );
                }
            } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
                $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
                foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
                    $tags[] = $this->feedLink(
                        $format,
                        $rctitle->getLocalURL( array( 'feed' => $format ) ),
                        # For grep: 'site-rss-feed', 'site-atom-feed'
                        $this->msg( "site-{$format}-feed", $sitename )->text()
                    );
                }
            }
        }

        # Canonical URL
        if ( $config->get( 'EnableCanonicalServerLink' ) ) {
            if ( $canonicalUrl !== false ) {
                $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
            } else {
                $reqUrl = $this->getRequest()->getRequestURL();
                $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
            }
        }
        if ( $canonicalUrl !== false ) {
            $tags[] = Html::element( 'link', array(
                'rel' => 'canonical',
                'href' => $canonicalUrl
            ) );
        }

        return $tags;
    }

    public function getHeadLinks() {
        wfDeprecated( __METHOD__, '1.24' );
        return implode( "\n", $this->getHeadLinksArray() );
    }

    private function feedLink( $type, $url, $text ) {
        return Html::element( 'link', array(
            'rel' => 'alternate',
            'type' => "application/$type+xml",
            'title' => $text,
            'href' => $url )
        );
    }

    public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
        $options = array();
        // Even though we expect the media type to be lowercase, but here we
        // force it to lowercase to be safe.
        if ( $media ) {
            $options['media'] = $media;
        }
        if ( $condition ) {
            $options['condition'] = $condition;
        }
        if ( $dir ) {
            $options['dir'] = $dir;
        }
        $this->styles[$style] = $options;
    }

    public function addInlineStyle( $style_css, $flip = 'noflip' ) {
        if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
            # If wanted, and the interface is right-to-left, flip the CSS
            $style_css = CSSJanus::transform( $style_css, true, false );
        }
        $this->mInlineStyles .= Html::inlineStyle( $style_css ) . "\n";
    }

    public function buildCssLinks() {
        global $wgContLang;

        $this->getSkin()->setupSkinUserCss( $this );

        // Add ResourceLoader styles
        // Split the styles into these groups
        $styles = array(
            'other' => array(),
            'user' => array(),
            'site' => array(),
            'private' => array(),
            'noscript' => array()
        );
        $links = array();
        $otherTags = ''; // Tags to append after the normal <link> tags
        $resourceLoader = $this->getResourceLoader();

        $moduleStyles = $this->getModuleStyles();

        // Per-site custom styles
        $moduleStyles[] = 'site';
        $moduleStyles[] = 'noscript';
        $moduleStyles[] = 'user.groups';

        // Per-user custom styles
        if ( $this->getConfig()->get( 'AllowUserCss' ) && $this->getTitle()->isCssSubpage() && $this->userCanPreview() ) {
            // We're on a preview of a CSS subpage
            // Exclude this page from the user module in case it's in there (bug 26283)
            $link = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_STYLES, false,
                array( 'excludepage' => $this->getTitle()->getPrefixedDBkey() )
            );
            $otherTags .= $link['html'];

            // Load the previewed CSS
            // If needed, Janus it first. This is user-supplied CSS, so it's
            // assumed to be right for the content language directionality.
            $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
            if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
                $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
            }
            $otherTags .= Html::inlineStyle( $previewedCSS ) . "\n";
        } else {
            // Load the user styles normally
            $moduleStyles[] = 'user';
        }

        // Per-user preference styles
        $moduleStyles[] = 'user.cssprefs';

        foreach ( $moduleStyles as $name ) {
            $module = $resourceLoader->getModule( $name );
            if ( !$module ) {
                continue;
            }
            $group = $module->getGroup();
            // Modules in groups different than the ones listed on top (see $styles assignment)
            // will be placed in the "other" group
            $styles[isset( $styles[$group] ) ? $group : 'other'][] = $name;
        }

        // We want site, private and user styles to override dynamically added
        // styles from modules, but we want dynamically added styles to override
        // statically added styles from other modules. So the order has to be
        // other, dynamic, site, private, user. Add statically added styles for
        // other modules
        $links[] = $this->makeResourceLoaderLink( $styles['other'], ResourceLoaderModule::TYPE_STYLES );
        // Add normal styles added through addStyle()/addInlineStyle() here
        $links[] = implode( "\n", $this->buildCssLinksArray() ) . $this->mInlineStyles;
        // Add marker tag to mark the place where the client-side loader should inject dynamic styles
        // We use a <meta> tag with a made-up name for this because that's valid HTML
        $links[] = Html::element(
            'meta',
            array( 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' )
        ) . "\n";

        // Add site, private and user styles
        // 'private' at present only contains user.options, so put that before 'user'
        // Any future private modules will likely have a similar user-specific character
        foreach ( array( 'site', 'noscript', 'private', 'user' ) as $group ) {
            $links[] = $this->makeResourceLoaderLink( $styles[$group],
                ResourceLoaderModule::TYPE_STYLES
            );
        }

        // Add stuff in $otherTags (previewed user CSS if applicable)
        return self::getHtmlFromLoaderLinks( $links ) . $otherTags;
    }

    public function buildCssLinksArray() {
        $links = array();

        // Add any extension CSS
        foreach ( $this->mExtStyles as $url ) {
            $this->addStyle( $url );
        }
        $this->mExtStyles = array();

        foreach ( $this->styles as $file => $options ) {
            $link = $this->styleLink( $file, $options );
            if ( $link ) {
                $links[$file] = $link;
            }
        }
        return $links;
    }

    protected function styleLink( $style, array $options ) {
        if ( isset( $options['dir'] ) ) {
            if ( $this->getLanguage()->getDir() != $options['dir'] ) {
                return '';
            }
        }

        if ( isset( $options['media'] ) ) {
            $media = self::transformCssMedia( $options['media'] );
            if ( is_null( $media ) ) {
                return '';
            }
        } else {
            $media = 'all';
        }

        if ( substr( $style, 0, 1 ) == '/' ||
            substr( $style, 0, 5 ) == 'http:' ||
            substr( $style, 0, 6 ) == 'https:' ) {
            $url = $style;
        } else {
            $config = $this->getConfig();
            $url = $config->get( 'StylePath' ) . '/' . $style . '?' . $config->get( 'StyleVersion' );
        }

        $link = Html::linkedStyle( $url, $media );

        if ( isset( $options['condition'] ) ) {
            $condition = htmlspecialchars( $options['condition'] );
            $link = "<!--[if $condition]>$link<![endif]-->";
        }
        return $link;
    }

    public static function transformCssMedia( $media ) {
        global $wgRequest;

        // http://www.w3.org/TR/css3-mediaqueries/#syntax
        $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';

        // Switch in on-screen display for media testing
        $switches = array(
            'printable' => 'print',
            'handheld' => 'handheld',
        );
        foreach ( $switches as $switch => $targetMedia ) {
            if ( $wgRequest->getBool( $switch ) ) {
                if ( $media == $targetMedia ) {
                    $media = '';
                } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
                    // This regex will not attempt to understand a comma-separated media_query_list
                    //
                    // Example supported values for $media:
                    // 'screen', 'only screen', 'screen and (min-width: 982px)' ),
                    // Example NOT supported value for $media:
                    // '3d-glasses, screen, print and resolution > 90dpi'
                    //
                    // If it's a print request, we never want any kind of screen stylesheets
                    // If it's a handheld request (currently the only other choice with a switch),
                    // we don't want simple 'screen' but we might want screen queries that
                    // have a max-width or something, so we'll pass all others on and let the
                    // client do the query.
                    if ( $targetMedia == 'print' || $media == 'screen' ) {
                        return null;
                    }
                }
            }
        }

        return $media;
    }

    public function addWikiMsg( /*...*/ ) {
        $args = func_get_args();
        $name = array_shift( $args );
        $this->addWikiMsgArray( $name, $args );
    }

    public function addWikiMsgArray( $name, $args ) {
        $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
    }

    public function wrapWikiMsg( $wrap /*, ...*/ ) {
        $msgSpecs = func_get_args();
        array_shift( $msgSpecs );
        $msgSpecs = array_values( $msgSpecs );
        $s = $wrap;
        foreach ( $msgSpecs as $n => $spec ) {
            if ( is_array( $spec ) ) {
                $args = $spec;
                $name = array_shift( $args );
                if ( isset( $args['options'] ) ) {
                    unset( $args['options'] );
                    wfDeprecated(
                        'Adding "options" to ' . __METHOD__ . ' is no longer supported',
                        '1.20'
                    );
                }
            } else {
                $args = array();
                $name = $spec;
            }
            $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
        }
        $this->addWikiText( $s );
    }

    public function includeJQuery( array $modules = array() ) {
        return array();
    }

    public function enableTOC( $flag = true ) {
        $this->mEnableTOC = $flag;
    }

    public function isTOCEnabled() {
        return $this->mEnableTOC;
    }

    public function enableSectionEditLinks( $flag = true ) {
        $this->mEnableSectionEditLinks = $flag;
    }

    public function sectionEditLinksEnabled() {
        return $this->mEnableSectionEditLinks;
    }
}