Log stream buffer fix

[mediawiki.git] / includes / OutputPage.php

<?php
if ( ! defined( 'MEDIAWIKI' ) )
        die( 1 );

/**
 * @todo document
 */
class OutputPage {
        var $mMetatags = array(), $mKeywords = array(), $mLinktags = array();
        var $mExtStyles = array();
        var $mPagetitle = '', $mBodytext = '', $mDebugtext = '';
        var $mHTMLtitle = '', $mIsarticle = true, $mPrintable = false;
        var $mSubtitle = '', $mRedirect = '', $mStatusCode;
        var $mLastModified = '', $mETag = false;
        var $mCategoryLinks = array(), $mLanguageLinks = array();
        var $mScripts = '', $mLinkColours, $mPageLinkTitle = '', $mHeadItems = array();
        var $mTemplateIds = array();

        var $mAllowUserJs;
        var $mSuppressQuickbar = false;
        var $mOnloadHandler = '';
        var $mDoNothing = false;
        var $mContainsOldMagic = 0, $mContainsNewMagic = 0;
        var $mIsArticleRelated = true;
        protected $mParserOptions = null; // lazy initialised, use parserOptions()
        var $mShowFeedLinks = false;
        var $mFeedLinksAppendQuery = false;
        var $mEnableClientCache = true;
        var $mArticleBodyOnly = false;

        var $mNewSectionLink = false;
        var $mHideNewSectionLink = false;
        var $mNoGallery = false;
        var $mPageTitleActionText = '';
        var $mParseWarnings = array();
        var $mSquidMaxage = 0;
        var $mRevisionId = null;
        protected $mTitle = null;

        /**
         * An array of stylesheet filenames (relative from skins path), with options
         * for CSS media, IE conditions, and RTL/LTR direction.
         * For internal use; add settings in the skin via $this->addStyle()
         */
        var $styles = array();

        private $mIndexPolicy = 'index';
        private $mFollowPolicy = 'follow';

        /**
         * Constructor
         * Initialise private variables
         */
        function __construct() {
                global $wgAllowUserJs;
                $this->mAllowUserJs = $wgAllowUserJs;
        }

        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;
        }

        /**
         * Set the HTTP status code to send with the output.
         *
         * @param int $statusCode
         * @return nothing
         */
        function setStatusCode( $statusCode ) { $this->mStatusCode = $statusCode; }

        /**
         * Add a new <meta> tag
         * To add an http-equiv meta tag, precede the name with "http:"
         *
         * @param $name tag name
         * @param $val tag value
         */
        function addMeta( $name, $val ) {
                array_push( $this->mMetatags, array( $name, $val ) );
        }

        function addKeyword( $text ) { array_push( $this->mKeywords, $text ); }
        function addScript( $script ) { $this->mScripts .= "\t\t".$script; }
        
        function addExtensionStyle( $url ) {
                $linkarr = array( 'rel' => 'stylesheet', 'href' => $url, 'type' => 'text/css' );
                array_push( $this->mExtStyles, $linkarr );
        }

        /**
         * Add a JavaScript file out of skins/common, or a given relative path.
         * @param string $file filename in skins/common or complete on-server path (/foo/bar.js)
         */
        function addScriptFile( $file ) {
                global $wgStylePath, $wgStyleVersion, $wgJsMimeType;
                if( substr( $file, 0, 1 ) == '/' ) {
                        $path = $file;
                } else {
                        $path =  "{$wgStylePath}/common/{$file}";
                }
                $this->addScript( 
                        Xml::element( 'script', 
                                array(
                                        'type' => $wgJsMimeType,
                                        'src' => "$path?$wgStyleVersion",
                                ),
                                '', false
                        )
                );      
        }
        
        /**
         * Add a self-contained script tag with the given contents
         * @param string $script JavaScript text, no <script> tags
         */
        function addInlineScript( $script ) {
                global $wgJsMimeType;
                $this->mScripts .= "<script type=\"$wgJsMimeType\">/*<![CDATA[*/\n$script\n/*]]>*/</script>";
        }

        function getScript() {
                return $this->mScripts . $this->getHeadItems();
        }

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

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

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

        function setETag($tag) { $this->mETag = $tag; }
        function setArticleBodyOnly($only) { $this->mArticleBodyOnly = $only; }
        function getArticleBodyOnly($only) { return $this->mArticleBodyOnly; }

        function addLink( $linkarr ) {
                # $linkarr should be an associative array of attributes. We'll escape on output.
                array_push( $this->mLinktags, $linkarr );
        }
        
        # Get all links added by extensions
        function getExtStyle() {
                return $this->mExtStyles;
        }

        function addMetadataLink( $linkarr ) {
                # note: buggy CC software only reads first "meta" link
                static $haveMeta = false;
                $linkarr['rel'] = ($haveMeta) ? 'alternate meta' : 'meta';
                $this->addLink( $linkarr );
                $haveMeta = true;
        }

        /**
         * checkLastModified tells the client to use the client-cached page if
         * possible. If sucessful, the OutputPage is disabled so that
         * any future call to OutputPage->output() have no effect.
         *
         * Side effect: sets mLastModified for Last-Modified header
         *
         * @return bool True iff cache-ok headers was sent.
         */
        function checkLastModified( $timestamp ) {
                global $wgCachePages, $wgCacheEpoch, $wgUser, $wgRequest;
                
                if ( !$timestamp || $timestamp == '19700101000000' ) {
                        wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
                        return false;
                }
                if( !$wgCachePages ) {
                        wfDebug( __METHOD__ . ": CACHE DISABLED\n", false );
                        return false;
                }
                if( $wgUser->getOption( 'nocache' ) ) {
                        wfDebug( __METHOD__ . ": USER DISABLED CACHE\n", false );
                        return false;
                }

                $timestamp = wfTimestamp( TS_MW, $timestamp );
                $modifiedTimes = array(
                        'page' => $timestamp,
                        'user' => $wgUser->getTouched(),
                        'epoch' => $wgCacheEpoch
                );
                wfRunHooks( 'OutputPageCheckLastModified', array( &$modifiedTimes ) );

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

                if( empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
                        wfDebug( __METHOD__ . ": client did not send If-Modified-Since header\n", false );
                        return false;
                }

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

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

                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 );

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

                # Not modified
                # Give a 304 response code and disable body output 
                wfDebug( __METHOD__ . ": NOT MODIFIED, $info\n", false );
                ini_set('zlib.output_compression', 0);
                $wgRequest->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;
        }

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

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

        /**
         * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
         *
         * @param $policy string The literal string to output as the contents of
         *   the meta tag.  Will be parsed according to the spec and output in
         *   standardized form.
         * @return null
         */
        public function setRobotPolicy( $policy ) {
                $policy = explode( ',', $policy );
                $policy = array_map( 'trim', $policy );

                # The default policy is follow, so if nothing is said explicitly, we
                # do that.
                if( in_array( 'nofollow', $policy ) ) {
                        $this->mFollowPolicy = 'nofollow';
                } else {
                        $this->mFollowPolicy = 'follow';
                }

                if( in_array( 'noindex', $policy ) ) {
                        $this->mIndexPolicy = 'noindex';
                } else {
                        $this->mIndexPolicy = 'index';
                }
        }

        /**
         * Set the index policy for the page, but leave the follow policy un-
         * touched.
         *
         * @param $policy string Either 'index' or 'noindex'.
         * @return null
         */
        public function setIndexPolicy( $policy ) {
                $policy = trim( $policy );
                if( in_array( $policy, array( 'index', 'noindex' ) ) ) {
                        $this->mIndexPolicy = $policy;
                }
        }

        /**
         * Set the follow policy for the page, but leave the index policy un-
         * touched.
         *
         * @param $policy string Either 'follow' or 'nofollow'.
         * @return null
         */
        public function setFollowPolicy( $policy ) {
                $policy = trim( $policy );
                if( in_array( $policy, array( 'follow', 'nofollow' ) ) ) {
                        $this->mFollowPolicy = $policy;
                }
        }

        /**
         * "HTML title" means the contents of <title>. It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
         */
        public function setHTMLTitle( $name ) {
                $this->mHTMLtitle = $name;
        }

        /**
         * "Page title" means the contents of <h1>. It is stored as a valid HTML fragment.
         * This function allows good tags like <sup> in the <h1> tag, but not bad tags like <script>.
         * This function automatically sets <title> to the same content as <h1> but with all tags removed.
         * Bad tags that were escaped in <h1> will still be escaped in <title>, and good tags like <i> will be dropped entirely.
         */
        public function setPageTitle( $name ) {
                global $wgContLang;
                $name = $wgContLang->convert( $name, true );
                # 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;

                $taction =  $this->getPageTitleActionText();
                if( !empty( $taction ) ) {
                        $name .= ' - '.$taction;
                }

                # change "<i>foo&amp;bar</i>" to "foo&bar"
                $this->setHTMLTitle( wfMsg( 'pagetitle', Sanitizer::stripAllTags( $nameWithTags ) ) );
        }
        
        public function setTitle( $t ) {
                $this->mTitle = $t;
        }
        
        public function getTitle() {
                if ( $this->mTitle instanceof Title ) {
                        return $this->mTitle;
                }
                else {
                        wfDebug( __METHOD__ . ' called and $mTitle is null. Return $wgTitle for sanity' );
                        global $wgTitle;
                        return $wgTitle;
                }
        }

        public function getHTMLTitle() { return $this->mHTMLtitle; }
        public function getPageTitle() { return $this->mPagetitle; }
        public function setSubtitle( $str ) { $this->mSubtitle = /*$this->parse(*/$str/*)*/; } // @bug 2514
        public function appendSubtitle( $str ) { $this->mSubtitle .= /*$this->parse(*/$str/*)*/; } // @bug 2514
        public function getSubtitle() { return $this->mSubtitle; }
        public function isArticle() { return $this->mIsarticle; }
        public function setPrintable() { $this->mPrintable = true; }
        public function isPrintable() { return $this->mPrintable; }
        public function setSyndicated( $show = true ) { $this->mShowFeedLinks = $show; }
        public function isSyndicated() { return $this->mShowFeedLinks; }
        public function setFeedAppendQuery( $val ) { $this->mFeedLinksAppendQuery = $val; }
        public function getFeedAppendQuery() { return $this->mFeedLinksAppendQuery; }
        public function setOnloadHandler( $js ) { $this->mOnloadHandler = $js; }
        public function getOnloadHandler() { return $this->mOnloadHandler; }
        public function disable() { $this->mDoNothing = true; }
        public function isDisabled() { return $this->mDoNothing; }

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

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

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

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

        /**
         * Add an array of categories, with names in the keys
         */
        public function addCategoryLinks( $categories ) {
                global $wgUser, $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 );
                $pageTable = $dbr->tableName( 'page' );
                $where = $lb->constructSet( 'page', $dbr );
                $propsTable = $dbr->tableName( 'page_props' );
                $sql = "SELECT page_id, page_namespace, page_title, page_len, page_is_redirect, pp_value
                        FROM $pageTable LEFT JOIN $propsTable ON pp_propname='hiddencat' AND pp_page=page_id WHERE $where";
                $res = $dbr->query( $sql, __METHOD__ );

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

                # Set all the values to 'normal'. This can be done with array_fill_keys in PHP 5.2.0+
                $categories = array_combine( array_keys( $categories ),
                        array_fill( 0, count( $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 ) ) ) {
                        $sk = $wgUser->getSkin();
                        foreach ( $categories as $category => $type ) {
                                $origcategory = $category;
                                $title = Title::makeTitleSafe( NS_CATEGORY, $category );
                                $wgContLang->findVariantLink( $category, $title, true );
                                if ( $category != $origcategory )
                                        if ( array_key_exists( $category, $categories ) )
                                                continue;
                                $text = $wgContLang->convertHtml( $title->getText() );
                                $this->mCategoryLinks[$type][] = $sk->makeLinkObj( $title, $text );
                        }
                }
        }

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

        public function suppressQuickbar() { $this->mSuppressQuickbar = true; }
        public function isQuickbarSuppressed() { return $this->mSuppressQuickbar; }

        public function disallowUserJs() { $this->mAllowUserJs = false; }
        public function isUserJsAllowed() { return $this->mAllowUserJs; }

        public function prependHTML( $text ) { $this->mBodytext = $text . $this->mBodytext; }
        public function addHTML( $text ) { $this->mBodytext .= $text; }
        public function clearHTML() { $this->mBodytext = ''; }
        public function getHTML() { return $this->mBodytext; }
        public function debug( $text ) { $this->mDebugtext .= $text; }

        /* @deprecated */
        public function setParserOptions( $options ) {
                wfDeprecated( __METHOD__ );
                return $this->parserOptions( $options );
        }

        public function parserOptions( $options = null ) {
                if ( !$this->mParserOptions ) {
                        $this->mParserOptions = new ParserOptions;
                }
                return wfSetVar( $this->mParserOptions, $options );
        }

        /**
         * Set the revision ID which will be seen by the wiki text parser
         * for things such as embedded {{REVISIONID}} variable use.
         * @param mixed $revid an integer, or NULL
         * @return mixed previous value
         */
        public function setRevisionId( $revid ) {
                $val = is_null( $revid ) ? null : intval( $revid );
                return wfSetVar( $this->mRevisionId, $val );
        }
        
        public function getRevisionId() {
                return $this->mRevisionId;
        }

        /**
         * Convert wikitext to HTML and add it to the buffer
         * Default assumes that the current page title will
         * be used.
         *
         * @param string $text
         * @param bool   $linestart
         */
        public function addWikiText( $text, $linestart = true ) {
                $title = $this->getTitle(); // Work arround E_STRICT
                $this->addWikiTextTitle( $text, $title, $linestart );
        }

        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 addWikiTextTitle($text, &$title, $linestart, $tidy = false) {
                global $wgParser;

                wfProfileIn( __METHOD__ );

                wfIncrStats( 'pcache_not_possible' );

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

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

                $popts->setTidy( $oldTidy );

                $this->addParserOutput( $parserOutput );

                wfProfileOut( __METHOD__ );
        }

        /**
         * @todo document
         * @param ParserOutput object &$parserOutput
         */
        public function addParserOutputNoText( &$parserOutput ) {
                global $wgExemptFromUserRobotsControl, $wgContentNamespaces;

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

                if( is_null( $wgExemptFromUserRobotsControl ) ) {
                        $bannedNamespaces = $wgContentNamespaces;
                } else {
                        $bannedNamespaces = $wgExemptFromUserRobotsControl;
                }
                if( !in_array( $this->getTitle()->getNamespace(), $bannedNamespaces ) ) {
                        # FIXME (bug 14900): This overrides $wgArticleRobotPolicies, and it
                        # shouldn't
                        $this->setIndexPolicy( $parserOutput->getIndexPolicy() );
                }

                $this->addKeywords( $parserOutput );
                $this->mParseWarnings = $parserOutput->getWarnings();
                if ( $parserOutput->getCacheTime() == -1 ) {
                        $this->enableClientCache( false );
                }
                $this->mNoGallery = $parserOutput->getNoGallery();
                $this->mHeadItems = array_merge( $this->mHeadItems, (array)$parserOutput->mHeadItems );
                // Versioning...
                foreach ( (array)$parserOutput->mTemplateIds as $ns => $dbks ) {
                        if ( isset( $this->mTemplateIds[$ns] ) ) {
                                $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
                        } else {
                                $this->mTemplateIds[$ns] = $dbks;
                        }
                }
                // Page title
                if( ( $dt = $parserOutput->getDisplayTitle() ) !== false )
                        $this->setPageTitle( $dt );
                else if ( ( $title = $parserOutput->getTitleText() ) != '' )
                        $this->setPageTitle( $title );

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

                wfRunHooks( 'OutputPageParserOutput', array( &$this, $parserOutput ) );
        }

        /**
         * @todo document
         * @param ParserOutput &$parserOutput
         */
        function addParserOutput( &$parserOutput ) {
                $this->addParserOutputNoText( $parserOutput );
                $text = $parserOutput->getText();
                wfRunHooks( 'OutputPageBeforeHTML',array( &$this, &$text ) );
                $this->addHTML( $text );
        }

        /**
         * Add wikitext to the buffer, assuming that this is the primary text for a page view
         * Saves the text into the parser cache if possible.
         *
         * @param string  $text
         * @param Article $article
         * @param bool    $cache
         * @deprecated Use Article::outputWikitext
         */
        public function addPrimaryWikiText( $text, $article, $cache = true ) {
                global $wgParser;

                wfDeprecated( __METHOD__ );

                $popts = $this->parserOptions();
                $popts->setTidy(true);
                $parserOutput = $wgParser->parse( $text, $article->mTitle,
                        $popts, true, true, $this->mRevisionId );
                $popts->setTidy(false);
                if ( $cache && $article && $parserOutput->getCacheTime() != -1 ) {
                        $parserCache = ParserCache::singleton();
                        $parserCache->save( $parserOutput, $article, $popts);
                }

                $this->addParserOutput( $parserOutput );
        }

        /**
         * @deprecated use addWikiTextTidy()
         */
        public function addSecondaryWikiText( $text, $linestart = true ) {
                wfDeprecated( __METHOD__ );
                $this->addWikiTextTitleTidy($text, $this->getTitle(), $linestart);
        }

        /**
         * Add wikitext with tidy enabled
         */
        public function addWikiTextTidy(  $text, $linestart = true ) {
                $title = $this->getTitle();
                $this->addWikiTextTitleTidy($text, $title, $linestart);
        }


        /**
         * Add the output of a QuickTemplate to the output buffer
         *
         * @param QuickTemplate $template
         */
        public function addTemplate( &$template ) {
                ob_start();
                $template->execute();
                $this->addHTML( ob_get_contents() );
                ob_end_clean();
        }

        /**
         * Parse wikitext and return the HTML.
         *
         * @param string $text
         * @param bool   $linestart Is this the start of a line?
         * @param bool   $interface ??
         */
        public function parse( $text, $linestart = true, $interface = false ) {
                global $wgParser;
                if( is_null( $this->getTitle() ) ) {
                        throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
                }
                $popts = $this->parserOptions();
                if ( $interface) { $popts->setInterfaceMessage(true); }
                $parserOutput = $wgParser->parse( $text, $this->getTitle(), $popts,
                        $linestart, true, $this->mRevisionId );
                if ( $interface) { $popts->setInterfaceMessage(false); }
                return $parserOutput->getText();
        }

        /** Parse wikitext, strip paragraphs, and return the HTML. */
        public function parseInline( $text, $linestart = true, $interface = false ) {
                $parsed = $this->parse( $text, $linestart, $interface );

                $m = array();
                if ( preg_match( '/^<p>(.*)\n?<\/p>\n?/sU', $parsed, $m ) ) {
                        $parsed = $m[1];
                }

                return $parsed;
        }

        /**
         * @param Article $article
         * @param User    $user
         *
         * @return bool True if successful, else false.
         */
        public function tryParserCache( &$article ) {
                $parserCache = ParserCache::singleton();
                $parserOutput = $parserCache->get( $article, $this->parserOptions() );
                if ( $parserOutput !== false ) {
                        $this->addParserOutput( $parserOutput );
                        return true;
                } else {
                        return false;
                }
        }

        /**
         * @param int $maxage Maximum cache time on the Squid, in seconds.
         */
        public function setSquidMaxage( $maxage ) {
                $this->mSquidMaxage = $maxage;
        }

        /**
         * Use enableClientCache(false) to force it to send nocache headers
         * @param $state ??
         */
        public function enableClientCache( $state ) {
                return wfSetVar( $this->mEnableClientCache, $state );
        }

        function getCacheVaryCookies() {
                global $wgCookiePrefix, $wgCacheVaryCookies;
                static $cookies;
                if ( $cookies === null ) {
                        $cookies = array_merge(
                                array(
                                        "{$wgCookiePrefix}Token",
                                        "{$wgCookiePrefix}LoggedOut",
                                        session_name()
                                ),
                                $wgCacheVaryCookies
                        );
                        wfRunHooks('GetCacheVaryCookies', array( $this, &$cookies ) );
                }
                return $cookies;
        }

        function uncacheableBecauseRequestVars() {
                global $wgRequest;
                return  $wgRequest->getText('useskin', false) === false
                        && $wgRequest->getText('uselang', false) === false;
        }

        /**
         * Check if the request has a cache-varying cookie header
         * If it does, it's very important that we don't allow public caching
         */
        function haveCacheVaryCookies() {
                global $wgRequest;
                $cookieHeader = $wgRequest->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 ) ) {
                                wfDebug( __METHOD__.": found $cookieName\n" );
                                return true;
                        }
                }
                wfDebug( __METHOD__.": no cache-varying cookies found\n" );
                return false;
        }

        /** Get a complete X-Vary-Options header */
        public function getXVO() {
                $cvCookies = $this->getCacheVaryCookies();
                $xvo = 'X-Vary-Options: Accept-Encoding;list-contains=gzip,Cookie;';
                $first = true;
                foreach ( $cvCookies as $cookieName ) {
                        if ( $first ) {
                                $first = false;
                        } else {
                                $xvo .= ';';
                        }
                        $xvo .= 'string-contains=' . $cookieName;
                }
                return $xvo;
        }

        public function sendCacheControl() {
                global $wgUseSquid, $wgUseESI, $wgUseETag, $wgSquidMaxage, $wgRequest;

                $response = $wgRequest->response();
                if ($wgUseETag && $this->mETag)
                        $response->header("ETag: $this->mETag");

                # 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( 'Vary: Accept-Encoding, Cookie' );

                # Add an X-Vary-Options header for Squid with Wikimedia patches
                $response->header( $this->getXVO() );

                if( !$this->uncacheableBecauseRequestVars() && $this->mEnableClientCache ) {
                        if( $wgUseSquid && session_id() == '' &&
                          ! $this->isPrintable() && $this->mSquidMaxage != 0 && !$this->haveCacheVaryCookies() )
                        {
                                if ( $wgUseESI ) {
                                        # We'll purge the proxy cache explicitly, but require end user agents
                                        # to revalidate against the proxy on each visit.
                                        # Surrogate-Control controls our Squid, Cache-Control downstream caches
                                        wfDebug( __METHOD__ . ": proxy caching with ESI; {$this->mLastModified} **\n", false );
                                        # start with a shorter timeout for initial testing
                                        # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
                                        $response->header( 'Surrogate-Control: max-age='.$wgSquidMaxage.'+'.$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", false );
                                        # 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", false );
                                $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", false );

                        # 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' );
                }
        }

        /**
         * Finally, all the text has been munged and accumulated into
         * the object, let's actually output it:
         */
        public function output() {
                global $wgUser, $wgOutputEncoding, $wgRequest;
                global $wgContLanguageCode, $wgDebugRedirects, $wgMimeType;
                global $wgJsMimeType, $wgUseAjax, $wgAjaxWatch;
                global $wgEnableMWSuggest, $wgUniversalEditButton;
                global $wgArticle;

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

                wfProfileIn( __METHOD__ );

                if ( '' != $this->mRedirect ) {
                        # Standards require redirect URLs to be absolute
                        $this->mRedirect = wfExpandUrl( $this->mRedirect );
                        if( $this->mRedirectCode == '301') {
                                if( !$wgDebugRedirects ) {
                                        $wgRequest->response()->header("HTTP/1.1 {$this->mRedirectCode} Moved Permanently");
                                }
                                $this->mLastModified = wfTimestamp( TS_RFC2822 );
                        }

                        $this->sendCacheControl();

                        $wgRequest->response()->header("Content-Type: text/html; charset=utf-8");
                        if( $wgDebugRedirects ) {
                                $url = htmlspecialchars( $this->mRedirect );
                                print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
                                print "<p>Location: <a href=\"$url\">$url</a></p>\n";
                                print "</body>\n</html>\n";
                        } else {
                                $wgRequest->response()->header( 'Location: '.$this->mRedirect );
                        }
                        wfProfileOut( __METHOD__ );
                        return;
                }
                elseif ( $this->mStatusCode )
                {
                        $statusMessage = array(
                                100 => 'Continue',
                                101 => 'Switching Protocols',
                                102 => 'Processing',
                                200 => 'OK',
                                201 => 'Created',
                                202 => 'Accepted',
                                203 => 'Non-Authoritative Information',
                                204 => 'No Content',
                                205 => 'Reset Content',
                                206 => 'Partial Content',
                                207 => 'Multi-Status',
                                300 => 'Multiple Choices',
                                301 => 'Moved Permanently',
                                302 => 'Found',
                                303 => 'See Other',
                                304 => 'Not Modified',
                                305 => 'Use Proxy',
                                307 => 'Temporary Redirect',
                                400 => 'Bad Request',
                                401 => 'Unauthorized',
                                402 => 'Payment Required',
                                403 => 'Forbidden',
                                404 => 'Not Found',
                                405 => 'Method Not Allowed',
                                406 => 'Not Acceptable',
                                407 => 'Proxy Authentication Required',
                                408 => 'Request Timeout',
                                409 => 'Conflict',
                                410 => 'Gone',
                                411 => 'Length Required',
                                412 => 'Precondition Failed',
                                413 => 'Request Entity Too Large',
                                414 => 'Request-URI Too Large',
                                415 => 'Unsupported Media Type',
                                416 => 'Request Range Not Satisfiable',
                                417 => 'Expectation Failed',
                                422 => 'Unprocessable Entity',
                                423 => 'Locked',
                                424 => 'Failed Dependency',
                                500 => 'Internal Server Error',
                                501 => 'Not Implemented',
                                502 => 'Bad Gateway',
                                503 => 'Service Unavailable',
                                504 => 'Gateway Timeout',
                                505 => 'HTTP Version Not Supported',
                                507 => 'Insufficient Storage'
                        );

                        if ( $statusMessage[$this->mStatusCode] )
                                $wgRequest->response()->header( 'HTTP/1.1 ' . $this->mStatusCode . ' ' . $statusMessage[$this->mStatusCode] );
                }

                $sk = $wgUser->getSkin();

                if ( $wgUseAjax ) {
                        $this->addScriptFile( 'ajax.js' );

                        wfRunHooks( 'AjaxAddScript', array( &$this ) );

                        if( $wgAjaxWatch && $wgUser->isLoggedIn() ) {
                                $this->addScriptFile( 'ajaxwatch.js' );
                        }
                        
                        if ( $wgEnableMWSuggest && !$wgUser->getOption( 'disablesuggest', false ) ){
                                $this->addScriptFile( 'mwsuggest.js' );
                        }
                }
                
                if( $wgUser->getBoolOption( 'editsectiononrightclick' ) ) {
                        $this->addScriptFile( 'rightclickedit.js' );
                }

                if( $wgUniversalEditButton ) {
                        if( isset( $wgArticle ) && $this->getTitle() && $this->getTitle()->quickUserCan( 'edit' )
                                && ( $this->getTitle()->exists() || $this->getTitle()->quickUserCan( 'create' ) ) ) {
                                // Original UniversalEditButton
                                $this->addLink( array(
                                        'rel' => 'alternate',
                                        'type' => 'application/x-wiki',
                                        'title' => wfMsg( 'edit' ),
                                        'href' => $this->getTitle()->getLocalURL( 'action=edit' )
                                ) );
                                // Alternate edit link
                                $this->addLink( array(
                                        'rel' => 'edit',
                                        'title' => wfMsg( 'edit' ),
                                        'href' => $this->getTitle()->getLocalURL( 'action=edit' )
                                ) );
                        }
                }
                
                # Buffer output; final headers may depend on later processing
                ob_start();

                $wgRequest->response()->header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
                $wgRequest->response()->header( 'Content-language: '.$wgContLanguageCode );

                if ($this->mArticleBodyOnly) {
                        $this->out($this->mBodytext);
                } else {
                        // 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( $this );
                        wfProfileOut( 'Output-skin' );
                }

                $this->sendCacheControl();
                ob_end_flush();
                wfProfileOut( __METHOD__ );
        }

        /**
         * Actually output something with print(). Performs an iconv to the
         * output encoding, if needed.
         * @param string $ins The string to output
         */
        public function out( $ins ) {
                global $wgInputEncoding, $wgOutputEncoding, $wgContLang;
                if ( 0 == strcmp( $wgInputEncoding, $wgOutputEncoding ) ) {
                        $outs = $ins;
                } else {
                        $outs = $wgContLang->iconv( $wgInputEncoding, $wgOutputEncoding, $ins );
                        if ( false === $outs ) { $outs = $ins; }
                }
                print $outs;
        }

        /**
         * @todo document
         */
        public static function setEncodings() {
                global $wgInputEncoding, $wgOutputEncoding;
                global $wgContLang;

                $wgInputEncoding = strtolower( $wgInputEncoding );

                if ( empty( $_SERVER['HTTP_ACCEPT_CHARSET'] ) ) {
                        $wgOutputEncoding = strtolower( $wgOutputEncoding );
                        return;
                }
                $wgOutputEncoding = $wgInputEncoding;
        }

        /**
         * Deprecated, use wfReportTime() instead.
         * @return string
         * @deprecated
         */
        public function reportTime() {
                wfDeprecated( __METHOD__ );
                $time = wfReportTime();
                return $time;
        }

        /**
         * Produce a "user is blocked" page.
         *
         * @param bool $return Whether to have a "return to $wgTitle" message or not.
         * @return nothing
         */
        function blockedPage( $return = true ) {
                global $wgUser, $wgContLang, $wgLang;

                $this->setPageTitle( wfMsg( 'blockedtitle' ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleRelated( false );

                $name = User::whoIs( $wgUser->blockedBy() );
                $reason = $wgUser->blockedFor();
                if( $reason == '' ) {
                        $reason = wfMsg( 'blockednoreason' );
                }
                $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $wgUser->mBlock->mTimestamp ), true );
                $ip = wfGetIP();

                $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";

                $blockid = $wgUser->mBlock->mId;

                $blockExpiry = $wgUser->mBlock->mExpiry;
                if ( $blockExpiry == 'infinity' ) {
                        // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
                        // Search for localization in 'ipboptions'
                        $scBlockExpiryOptions = wfMsg( 'ipboptions' );
                        foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
                                if ( strpos( $option, ":" ) === false )
                                        continue;
                                list( $show, $value ) = explode( ":", $option );
                                if ( $value == 'infinite' || $value == 'indefinite' ) {
                                        $blockExpiry = $show;
                                        break;
                                }
                        }
                } else {
                        $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
                }

                if ( $wgUser->mBlock->mAuto ) {
                        $msg = 'autoblockedtext';
                } else {
                        $msg = 'blockedtext';
                }

                /* $ip returns who *is* being blocked, $intended contains who was meant to be blocked.
                 * This could be a username, an ip range, or a single ip. */
                $intended = $wgUser->mBlock->mAddress;

                $this->addWikiMsg( $msg, $link, $reason, $ip, $name, $blockid, $blockExpiry, $intended, $blockTimestamp );

                # Don't auto-return to special pages
                if( $return ) {
                        $return = $this->getTitle()->getNamespace() > -1 ? $this->getTitle() : null;
                        $this->returnToMain( null, $return );
                }
        }

        /**
         * Output a standard error page
         *
         * @param string $title Message key for page title
         * @param string $msg Message key for page text
         * @param array $params Message parameters
         */
        public function showErrorPage( $title, $msg, $params = array() ) {
                if ( $this->getTitle() ) {
                        $this->mDebugtext .= 'Original title: ' . $this->getTitle()->getPrefixedText() . "\n";
                }
                $this->setPageTitle( wfMsg( $title ) );
                $this->setHTMLTitle( wfMsg( 'errorpagetitle' ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleRelated( false );
                $this->enableClientCache( false );
                $this->mRedirect = '';
                $this->mBodytext = '';

                array_unshift( $params, 'parse' );
                array_unshift( $params, $msg );
                $this->addHTML( call_user_func_array( 'wfMsgExt', $params ) );

                $this->returnToMain();
        }

        /**
         * Output a standard permission error page
         *
         * @param array $errors Error message keys
         */
        public function showPermissionsErrorPage( $errors, $action = null )
        {
                $this->mDebugtext .= 'Original title: ' .
                $this->getTitle()->getPrefixedText() . "\n";
                $this->setPageTitle( wfMsg( 'permissionserrors' ) );
                $this->setHTMLTitle( wfMsg( 'permissionserrors' ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleRelated( false );
                $this->enableClientCache( false );
                $this->mRedirect = '';
                $this->mBodytext = '';
                $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
        }

        /** @deprecated */
        public function errorpage( $title, $msg ) {
                wfDeprecated( __METHOD__ );
                throw new ErrorPageError( $title, $msg );
        }

        /**
         * Display an error page indicating that a given version of MediaWiki is
         * required to use it
         *
         * @param mixed $version The version of MediaWiki needed to use the page
         */
        public function versionRequired( $version ) {
                $this->setPageTitle( wfMsg( 'versionrequired', $version ) );
                $this->setHTMLTitle( wfMsg( 'versionrequired', $version ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleRelated( false );
                $this->mBodytext = '';

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

        /**
         * Display an error page noting that a given permission bit is required.
         *
         * @param string $permission key required
         */
        public function permissionRequired( $permission ) {
                global $wgLang;

                $this->setPageTitle( wfMsg( 'badaccess' ) );
                $this->setHTMLTitle( wfMsg( 'errorpagetitle' ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleRelated( false );
                $this->mBodytext = '';

                $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
                        User::getGroupsWithPermission( $permission ) );
                if( $groups ) {
                        $this->addWikiMsg( 'badaccess-groups',
                                $wgLang->commaList( $groups ),
                                count( $groups) );
                } else {
                        $this->addWikiMsg( 'badaccess-group0' );
                }
                $this->returnToMain();
        }

        /**
         * Use permissionRequired.
         * @deprecated
         */
        public function sysopRequired() {
                throw new MWException( "Call to deprecated OutputPage::sysopRequired() method\n" );
        }

        /**
         * Use permissionRequired.
         * @deprecated
         */
        public function developerRequired() {
                throw new MWException( "Call to deprecated OutputPage::developerRequired() method\n" );
        }

        /**
         * Produce the stock "please login to use the wiki" page
         */
        public function loginToUse() {
                global $wgUser, $wgContLang;

                if( $wgUser->isLoggedIn() ) {
                        $this->permissionRequired( 'read' );
                        return;
                }

                $skin = $wgUser->getSkin();

                $this->setPageTitle( wfMsg( 'loginreqtitle' ) );
                $this->setHtmlTitle( wfMsg( 'errorpagetitle' ) );
                $this->setRobotPolicy( 'noindex,nofollow' );
                $this->setArticleFlag( false );

                $loginTitle = SpecialPage::getTitleFor( 'Userlogin' );
                $loginLink = $skin->makeKnownLinkObj( $loginTitle, wfMsgHtml( 'loginreqlink' ), 'returnto=' . $this->getTitle()->getPrefixedUrl() );
                $this->addHTML( wfMsgWikiHtml( 'loginreqpagetext', $loginLink ) );
                $this->addHTML( "\n<!--" . $this->getTitle()->getPrefixedUrl() . "-->" );

                # Don't return to the main page if the user can't read it
                # otherwise we'll end up in a pointless loop
                $mainPage = Title::newMainPage();
                if( $mainPage->userCanRead() )
                        $this->returnToMain( null, $mainPage );
        }

        /** @deprecated */
        public function databaseError( $fname, $sql, $error, $errno ) {
                throw new MWException( "OutputPage::databaseError is obsolete\n" );
        }

        /**
         * @param array $errors An array of arrays returned by Title::getUserPermissionsErrors
         * @return string The wikitext error-messages, formatted into a list.
         */
        public function formatPermissionsErrorMessage( $errors, $action = null ) {
                if ($action == null) {
                        $text = wfMsgNoTrans( 'permissionserrorstext', count($errors)). "\n\n";
                } else {
                        global $wgLang;
                        $action_desc = wfMsg( "action-$action" );
                        $text = wfMsgNoTrans( 'permissionserrorstext-withaction', count($errors), $action_desc ) . "\n\n";
                }

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

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

                return $text;
        }

        /**
         * Display a page stating that the Wiki is in read-only mode,
         * and optionally show the source of the page that the user
         * was trying to edit.  Should only be called (for this
         * purpose) after wfReadOnly() has returned true.
         *
         * For historical reasons, this function is _also_ used to
         * show the error message when a user tries to edit a page
         * they are not allowed to edit.  (Unless it's because they're
         * blocked, then we show blockedPage() instead.)  In this
         * case, the second parameter should be set to true and a list
         * of reasons supplied as the third parameter.
         *
         * @todo Needs to be split into multiple functions.
         *
         * @param string $source    Source code to show (or null).
         * @param bool   $protected Is this a permissions error?
         * @param array  $reasons   List of reasons for this error, as returned by Title::getUserPermissionsErrors().
         */
        public function readOnlyPage( $source = null, $protected = false, $reasons = array(), $action = null ) {
                global $wgUser;
                $skin = $wgUser->getSkin();

                $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( wfMsg( 'viewsource' ) );
                                $this->setSubtitle( wfMsg( 'viewsourcefor', $skin->makeKnownLinkObj( $this->getTitle() ) ) );
                        } else {
                                $this->setPageTitle( wfMsg( 'badaccess' ) );
                        }
                        $this->addWikiText( $this->formatPermissionsErrorMessage( $reasons, $action ) );
                } else {
                        // Wiki is read only
                        $this->setPageTitle( wfMsg( 'readonly' ) );
                        $reason = wfReadOnlyReason();
                        $this->wrapWikiMsg( '<div class="mw-readonly-error">$1</div>', array( 'readonlytext', $reason ) );
                }

                // Show source, if supplied
                if( is_string( $source ) ) {
                        $this->addWikiMsg( 'viewsourcetext' );
                        $text = Xml::openElement( 'textarea',
                                                array( 'id'   => 'wpTextbox1',
                                                       'name' => 'wpTextbox1',
                                                       'cols' => $wgUser->getOption( 'cols' ),
                                                       'rows' => $wgUser->getOption( 'rows' ),
                                                       'readonly' => 'readonly' ) );
                        $text .= htmlspecialchars( $source );
                        $text .= Xml::closeElement( 'textarea' );
                        $this->addHTML( $text );

                        // Show templates used by this article
                        $skin = $wgUser->getSkin();
                        $article = new Article( $this->getTitle() );
                        $this->addHTML( "<div class='templatesUsed'>
{$skin->formatTemplates( $article->getUsedTemplates() )}
</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() );
                }
        }

        /** @deprecated */
        public function fatalError( $message ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( $message );
        }

        /** @deprecated */
        public function unexpectedValueError( $name, $val ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( wfMsg( 'unexpected', $name, $val ) );
        }

        /** @deprecated */
        public function fileCopyError( $old, $new ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( wfMsg( 'filecopyerror', $old, $new ) );
        }

        /** @deprecated */
        public function fileRenameError( $old, $new ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( wfMsg( 'filerenameerror', $old, $new ) );
        }

        /** @deprecated */
        public function fileDeleteError( $name ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( wfMsg( 'filedeleteerror', $name ) );
        }

        /** @deprecated */
        public function fileNotFoundError( $name ) {
                wfDeprecated( __METHOD__ );
                throw new FatalError( wfMsg( 'filenotfound', $name ) );
        }

        public function showFatalError( $message ) {
                $this->setPageTitle( wfMsg( "internalerror" ) );
                $this->setRobotPolicy( "noindex,nofollow" );
                $this->setArticleRelated( false );
                $this->enableClientCache( false );
                $this->mRedirect = '';
                $this->mBodytext = $message;
        }

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

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

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

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

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

        /**
         * Add a "return to" link pointing to a specified title
         *
         * @param Title $title Title to link
         */
        public function addReturnTo( $title ) {
                global $wgUser;
                $this->addLink( array( 'rel' => 'next', 'href' => $title->getFullUrl() ) );
                $link = wfMsg( 'returnto', $wgUser->getSkin()->makeLinkObj( $title ) );
                $this->addHTML( "<p>{$link}</p>\n" );
        }

        /**
         * Add a "return to" link pointing to a specified title,
         * or the title indicated in the request, or else the main page
         *
         * @param null $unused No longer used
         * @param Title $returnto Title to return to
         */
        public function returnToMain( $unused = null, $returnto = NULL ) {
                global $wgRequest;

                if ( $returnto == NULL ) {
                        $returnto = $wgRequest->getText( 'returnto' );
                }

                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 );
        }

        /**
         * This function takes the title (first item of mGoodLinks), categories, existing and broken links for the page
         * and uses the first 10 of them for META keywords
         *
         * @param ParserOutput &$parserOutput
         */
        private function addKeywords( &$parserOutput ) {
                $this->addKeyword( $this->getTitle()->getPrefixedText() );
                $count = 1;
                $links2d =& $parserOutput->getLinks();
                if ( !is_array( $links2d ) ) {
                        return;
                }
                foreach ( $links2d as $dbkeys ) {
                        foreach( $dbkeys as $dbkey => $unused ) {
                                $this->addKeyword( $dbkey );
                                if ( ++$count > 10 ) {
                                        break 2;
                                }
                        }
                }
        }

        /**
         * @return string The doctype, opening <html>, and head element.
         */
        public function headElement( Skin $sk ) {
                global $wgDocType, $wgDTD, $wgContLanguageCode, $wgOutputEncoding, $wgMimeType;
                global $wgXhtmlDefaultNamespace, $wgXhtmlNamespaces;
                global $wgContLang, $wgUseTrackbacks, $wgStyleVersion;

                $this->addMeta( "http:Content-type", "$wgMimeType; charset={$wgOutputEncoding}" );
                $this->addStyle( 'common/wikiprintable.css', 'print' );
                $sk->setupUserCss( $this );

                $ret = '';

                if( $wgMimeType == 'text/xml' || $wgMimeType == 'application/xhtml+xml' || $wgMimeType == 'application/xml' ) {
                        $ret .= "<?xml version=\"1.0\" encoding=\"$wgOutputEncoding\" ?" . ">\n";
                }

                $ret .= "<!DOCTYPE html PUBLIC \"$wgDocType\"\n        \"$wgDTD\">\n";

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

                $rtl = $wgContLang->isRTL() ? " dir='RTL'" : '';
                $ret .= "<html xmlns=\"{$wgXhtmlDefaultNamespace}\" ";
                foreach($wgXhtmlNamespaces as $tag => $ns) {
                        $ret .= "xmlns:{$tag}=\"{$ns}\" ";
                }
                $ret .= "xml:lang=\"$wgContLanguageCode\" lang=\"$wgContLanguageCode\" $rtl>\n";
                $ret .= "<head>\n<title>" . htmlspecialchars( $this->getHTMLTitle() ) . "</title>\n\t\t";
                $ret .= implode( "\t\t", array(
                        $this->getHeadLinks(),
                        $this->buildCssLinks(),
                        $sk->getHeadScripts( $this->mAllowUserJs ),
                        $this->mScripts,
                        $this->getHeadItems(),
                ));
                if( $sk->usercss ){
                        $ret .= "<style type='text/css'>{$sk->usercss}</style>";
                }

                if ($wgUseTrackbacks && $this->isArticleRelated())
                        $ret .= $this->getTitle()->trackbackRDF();

                $ret .= "</head>\n";
                return $ret;
        }
        
        protected function addDefaultMeta() {
                global $wgVersion;
                $this->addMeta( 'http:Content-Style-Type', 'text/css' ); //bug 15835
                $this->addMeta( 'generator', "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
                        $this->addMeta( 'robots', $p );
                }

                if ( count( $this->mKeywords ) > 0 ) {
                        $strip = array(
                                "/<.*?" . ">/" => '',
                                "/_/" => ' '
                        );
                        $this->addMeta( 'keywords', preg_replace(array_keys($strip), array_values($strip),implode( ",", $this->mKeywords ) ) );
                }
        }

        /**
         * @return string HTML tag links to be put in the header.
         */
        public function getHeadLinks() {
                global $wgRequest, $wgFeed;
                
                // Ideally this should happen earlier, somewhere. :P
                $this->addDefaultMeta();
                
                $tags = array();
                
                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';
                        }
                        $tags[] = Xml::element( 'meta',
                                array(
                                        $a => $tag[0],
                                        'content' => $tag[1] ) );
                }
                foreach ( $this->mLinktags as $tag ) {
                        $tags[] = Xml::element( 'link', $tag );
                }

                if( $wgFeed ) {
                        foreach( $this->getSyndicationLinks() as $format => $link ) {
                                # Use the page name for the title (accessed through $wgTitle since
                                # there's no other way).  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,
                                        $link,
                                        wfMsg( "page-{$format}-feed", $this->getTitle()->getPrefixedText() ) ); # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
                        }

                        # 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.
                        
                        global $wgOverrideSiteFeed, $wgSitename, $wgFeedClasses;
                        $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
                        
                        if ( $wgOverrideSiteFeed ) {
                                foreach ( $wgOverrideSiteFeed as $type => $feedUrl ) { 
                                        $tags[] = $this->feedLink (
                                                $type,
                                                htmlspecialchars( $feedUrl ),
                                                wfMsg( "site-{$type}-feed", $wgSitename ) );
                                }
                        }
                        else if ( $this->getTitle()->getPrefixedText() != $rctitle->getPrefixedText() ) {
                                foreach( $wgFeedClasses as $format => $class ) {
                                        $tags[] = $this->feedLink(
                                                $format,
                                                $rctitle->getLocalURL( "feed={$format}" ),
                                                wfMsg( "site-{$format}-feed", $wgSitename ) ); # For grep: 'site-rss-feed', 'site-atom-feed'.
                                }
                        }
                }

                return implode( "\n\t\t", $tags ) . "\n";
        }

        /**
         * Return URLs for each supported syndication format for this page.
         * @return array associating format keys with URLs
         */
        public function getSyndicationLinks() {
                global $wgFeedClasses;
                $links = array();

                if( $this->isSyndicated() ) {
                        if( is_string( $this->getFeedAppendQuery() ) ) {
                                $appendQuery = "&" . $this->getFeedAppendQuery();
                        } else {
                                $appendQuery = "";
                        }

                        foreach( $wgFeedClasses as $format => $class ) {
                                $links[$format] = $this->getTitle()->getLocalUrl( "feed=$format{$appendQuery}" );
                        }
                }
                return $links;
        }

        /**
         * Generate a <link rel/> for an RSS feed.
         */
        private function feedLink( $type, $url, $text ) {
                return Xml::element( 'link', array(
                        'rel' => 'alternate',
                        'type' => "application/$type+xml",
                        'title' => $text,
                        'href' => $url ) );
        }

        /**
         * Add a local or specified stylesheet, with the given media options.
         * Meant primarily for internal use...
         *
         * @param $media -- to specify a media type, 'screen', 'printable', 'handheld' or any.
         * @param $conditional -- for IE conditional comments, specifying an IE version
         * @param $dir -- set to 'rtl' or 'ltr' for direction-specific sheets
         */
        public function addStyle( $style, $media='', $condition='', $dir='' ) {
                $options = array();
                if( $media )
                        $options['media'] = $media;
                if( $condition )
                        $options['condition'] = $condition;
                if( $dir )
                        $options['dir'] = $dir;
                $this->styles[$style] = $options;
        }

        /**
         * Build a set of <link>s for the stylesheets specified in the $this->styles array.
         * These will be applied to various media & IE conditionals.
         */
        public function buildCssLinks() {
                $links = array();
                foreach( $this->styles as $file => $options ) {
                        $link = $this->styleLink( $file, $options );
                        if( $link )
                                $links[] = $link;
                }

                return implode( "\n\t\t", $links );
        }

        protected function styleLink( $style, $options ) {
                global $wgRequest;

                if( isset( $options['dir'] ) ) {
                        global $wgContLang;
                        $siteDir = $wgContLang->isRTL() ? 'rtl' : 'ltr';
                        if( $siteDir != $options['dir'] )
                                return '';
                }

                if( isset( $options['media'] ) ) {
                        $media = $this->transformCssMedia( $options['media'] );
                        if( is_null( $media ) ) {
                                return '';
                        }
                } else {
                        $media = '';
                }

                if( substr( $style, 0, 1 ) == '/' ||
                        substr( $style, 0, 5 ) == 'http:' ||
                        substr( $style, 0, 6 ) == 'https:' ) {
                        $url = $style;
                } else {
                        global $wgStylePath, $wgStyleVersion;
                        $url = $wgStylePath . '/' . $style . '?' . $wgStyleVersion;
                }

                $attribs = array(
                        'rel' => 'stylesheet',
                        'href' => $url,
                        'type' => 'text/css' );
                if( $media ) {
                        $attribs['media'] = $media;
                }

                $link = Xml::element( 'link', $attribs );

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

        function transformCssMedia( $media ) {
                global $wgRequest, $wgHandheldForIPhone;

                // 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( $media == 'screen' ) {
                                        return null;
                                }
                        }
                }

                // Expand longer media queries as iPhone doesn't grok 'handheld'
                if( $wgHandheldForIPhone ) {
                        $mediaAliases = array(
                                'screen' => 'screen and (min-device-width: 481px)',
                                'handheld' => 'handheld, only screen and (max-device-width: 480px)',
                        );

                        if( isset( $mediaAliases[$media] ) ) {
                                $media = $mediaAliases[$media];
                        }
                }

                return $media;
        }

        /**
         * Turn off regular page output and return an error reponse
         * for when rate limiting has triggered.
         */
        public function rateLimited() {

                $this->setPageTitle(wfMsg('actionthrottled'));
                $this->setRobotPolicy( 'noindex,follow' );
                $this->setArticleRelated( false );
                $this->enableClientCache( false );
                $this->mRedirect = '';
                $this->clearHTML();
                $this->setStatusCode(503);
                $this->addWikiMsg( 'actionthrottledtext' );

                $this->returnToMain( null, $this->getTitle() );
        }

        /**
         * Show an "add new section" link?
         *
         * @return bool
         */
        public function showNewSectionLink() {
                return $this->mNewSectionLink;
        }

        /**
        * Forcibly hide the new section link?
        *
        * @return bool
        */
        public function forceHideNewSectionLink() {
                return $this->mHideNewSectionLink;
        }

        /**
         * Show a warning about slave lag
         *
         * If the lag is higher than $wgSlaveLagCritical seconds,
         * then the warning is a bit more obvious. If the lag is
         * lower than $wgSlaveLagWarning, then no warning is shown.
         *
         * @param int $lag Slave lag
         */
        public function showLagWarning( $lag ) {
                global $wgSlaveLagWarning, $wgSlaveLagCritical;
                if( $lag >= $wgSlaveLagWarning ) {
                        $message = $lag < $wgSlaveLagCritical
                                ? 'lag-warn-normal'
                                : 'lag-warn-high';
                        $warning = wfMsgExt( $message, 'parse', $lag );
                        $this->addHTML( "<div class=\"mw-{$message}\">\n{$warning}\n</div>\n" );
                }
        }

        /**
         * Add a wikitext-formatted message to the output.
         * This is equivalent to:
         *
         *    $wgOut->addWikiText( wfMsgNoTrans( ... ) )
         */
        public function addWikiMsg( /*...*/ ) {
                $args = func_get_args();
                $name = array_shift( $args );
                $this->addWikiMsgArray( $name, $args );
        }

        /**
         * Add a wikitext-formatted message to the output.
         * Like addWikiMsg() except the parameters are taken as an array
         * instead of a variable argument list.
         *
         * $options is passed through to wfMsgExt(), see that function for details.
         */
        public function addWikiMsgArray( $name, $args, $options = array() ) {
                $options[] = 'parse';
                $text = wfMsgExt( $name, $options, $args );
                $this->addHTML( $text );
        }

        /**
         * This function takes a number of message/argument specifications, wraps them in
         * some overall structure, and then parses the result and adds it to the output.
         *
         * In the $wrap, $1 is replaced with the first message, $2 with the second, and so
         * on. The subsequent arguments may either be strings, in which case they are the
         * message names, or an arrays, in which case the first element is the message name,
         * and subsequent elements are the parameters to that message.
         *
         * The special named parameter 'options' in a message specification array is passed
         * through to the $options parameter of wfMsgExt().
         *
         * Don't use this for messages that are not in users interface language.
         *
         * For example:
         *
         *    $wgOut->wrapWikiMsg( '<div class="error">$1</div>', 'some-error' );
         *
         * Is equivalent to:
         *
         *    $wgOut->addWikiText( '<div class="error">' . wfMsgNoTrans( 'some-error' ) . '</div>' );
         */
        public function wrapWikiMsg( $wrap /*, ...*/ ) {
                $msgSpecs = func_get_args();
                array_shift( $msgSpecs );
                $msgSpecs = array_values( $msgSpecs );
                $s = $wrap;
                foreach ( $msgSpecs as $n => $spec ) {
                        $options = array();
                        if ( is_array( $spec ) ) {
                                $args = $spec;
                                $name = array_shift( $args );
                                if ( isset( $args['options'] ) ) {
                                        $options = $args['options'];
                                        unset( $args['options'] );
                                }
                        }  else {
                                $args = array();
                                $name = $spec;
                        }
                        $s = str_replace( '$' . ( $n + 1 ), wfMsgExt( $name, $options, $args ), $s );
                }
                $this->addHTML( $this->parse( $s, /*linestart*/true, /*uilang*/true ) );
        }
}