wiki.techinc.nl/includes/OutputPage.php

<?php
/**
 * @package MediaWiki
 */

/**
 * This is not a valid entry point, perform no further processing unless MEDIAWIKI is defined
 */
if( defined( 'MEDIAWIKI' ) ) {

# See design.doc

if($wgUseTeX) require_once( 'Math.php' );

/**
 * @todo document
 * @package MediaWiki
 */
class OutputPage {
	var $mHeaders, $mCookies, $mMetatags, $mKeywords;
	var $mLinktags, $mPagetitle, $mBodytext, $mDebugtext;
	var $mHTMLtitle, $mRobotpolicy, $mIsarticle, $mPrintable;
	var $mSubtitle, $mRedirect;
	var $mLastModified, $mCategoryLinks;
	var $mScripts, $mLinkColours;
	
	var $mSuppressQuickbar;
	var $mOnloadHandler;
	var $mDoNothing;
	var $mContainsOldMagic, $mContainsNewMagic;
	var $mIsArticleRelated;
	var $mParserOptions;
	var $mShowFeedLinks = false;
	var $mEnableClientCache = true;

	/**
	 * Constructor
	 * Initialise private variables
	 */
	function OutputPage() {
		$this->mHeaders = $this->mCookies = $this->mMetatags =
		$this->mKeywords = $this->mLinktags = array();
		$this->mHTMLtitle = $this->mPagetitle = $this->mBodytext =
		$this->mRedirect = $this->mLastModified =
		$this->mSubtitle = $this->mDebugtext = $this->mRobotpolicy =
		$this->mOnloadHandler = '';
		$this->mIsArticleRelated = $this->mIsarticle = $this->mPrintable = true;
		$this->mSuppressQuickbar = $this->mPrintable = false;
		$this->mLanguageLinks = array();
		$this->mCategoryLinks = array() ;
		$this->mDoNothing = false;
		$this->mContainsOldMagic = $this->mContainsNewMagic = 0;
		$this->mParserOptions = ParserOptions::newFromUser( $temp = NULL );
		$this->mSquidMaxage = 0;
		$this->mScripts = '';
	}

	function addHeader( $name, $val ) { array_push( $this->mHeaders, $name.': '.$val ) ; }
	function addCookie( $name, $val ) { array_push( $this->mCookies, array( $name, $val ) ); }
	function redirect( $url, $responsecode = '302' ) { $this->mRedirect = $url; $this->mRedirectCode = $responsecode; }

	# To add an http-equiv meta tag, precede the name with "http:"
	function addMeta( $name, $val ) { array_push( $this->mMetatags, array( $name, $val ) ); }
	function addKeyword( $text ) { array_push( $this->mKeywords, $text ); }
	function addScript( $script ) { $this->mScripts .= $script; }
	function getScript() { return $this->mScripts; }

	function addLink( $linkarr ) {
		# $linkarr should be an associative array of attributes. We'll escape on output.
		array_push( $this->mLinktags, $linkarr );
	}

	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. The method
	 * returns true iff cache-ok headers was sent.
	 */
	function checkLastModified ( $timestamp ) {
		global $wgLang, $wgCachePages, $wgUser;
		$timestamp=wfTimestamp(TS_MW,$timestamp);
		if( !$wgCachePages ) {
			wfDebug( "CACHE DISABLED\n", false );
			return;
		}
		if( $wgUser->getOption( 'nocache' ) ) {
			wfDebug( "USER DISABLED CACHE\n", false );
			return;
		}

		$lastmod = wfTimestamp( TS_RFC2822, max( $timestamp, $wgUser->mTouched ) );

		if( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
			# IE sends sizes after the date like this:
			# Wed, 20 Aug 2003 06:51:19 GMT; length=5202
			# this breaks strtotime().
			$modsince = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
			$ismodsince = wfTimestamp( TS_MW, strtotime( $modsince ) );
			wfDebug( "-- client send If-Modified-Since: " . $modsince . "\n", false );
			wfDebug( "--  we might send Last-Modified : $lastmod\n", false );
			if( ($ismodsince >= $timestamp ) && $wgUser->validateCache( $ismodsince ) ) {
				# Make sure you're in a place you can leave when you call us!
				header( "HTTP/1.0 304 Not Modified" );
				$this->mLastModified = $lastmod;
				$this->sendCacheControl();
				wfDebug( "CACHED client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp\n", false );
				$this->disable();
				return true;
			} else {
				wfDebug( "READY  client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp\n", false );
				$this->mLastModified = $lastmod;
			}
		} else {
			wfDebug( "We're confused.\n", false );
			$this->mLastModified = $lastmod;
		}
	}

	function getPageTitleActionText () {
		global $action;
		switch($action) {
			case 'edit':
				return wfMsg('edit');
			case 'history':
				return wfMsg('history_short');
			case 'protect':
				return wfMsg('protect');
			case 'unprotect':
				return wfMsg('unprotect');
			case 'delete':
				return wfMsg('delete');
			case 'watch':
				return wfMsg('watch');
			case 'unwatch':
				return wfMsg('unwatch');
			case 'submit':
				return wfMsg('preview');
			case 'info':
				return wfMsg('info_short');
			default:
				return '';
		}
	}

	function setRobotpolicy( $str ) { $this->mRobotpolicy = $str; }
	function setHTMLTitle( $name ) {$this->mHTMLtitle = $name; }
	function setPageTitle( $name ) {
		global $action, $wgContLang;
		$name = $wgContLang->convert($name, true);
		$this->mPagetitle = $name;
		if(!empty($action)) {
			$taction =  $this->getPageTitleActionText();
			if( !empty( $taction ) ) {
				$name .= ' - '.$taction;
			}
		}
		$this->setHTMLTitle( $name . ' - ' . wfMsg( 'wikititlesuffix' ) );
	}
	function getHTMLTitle() { return $this->mHTMLtitle; }
	function getPageTitle() { return $this->mPagetitle; }
	function setSubtitle( $str ) { $this->mSubtitle = $str; }
	function getSubtitle() { return $this->mSubtitle; }
	function isArticle() { return $this->mIsarticle; }
	function setPrintable() { $this->mPrintable = true; }
	function isPrintable() { return $this->mPrintable; }
	function setSyndicated( $show = true ) { $this->mShowFeedLinks = $show; }
	function isSyndicated() { return $this->mShowFeedLinks; }
	function setOnloadHandler( $js ) { $this->mOnloadHandler = $js; }
	function getOnloadHandler() { return $this->mOnloadHandler; }
	function disable() { $this->mDoNothing = true; }

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

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

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

	function getCategoryLinks() {
		return $this->mCategoryLinks;
	}
	function addCategoryLinks($newLinkArray) {
		$this->mCategoryLinks += $newLinkArray;
	}
	function setCategoryLinks($newLinkArray) {
		$this->mCategoryLinks += $newLinkArray;
	}

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

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

	function setParserOptions( $options ) {
		return wfSetVar( $this->mParserOptions, $options );
	}

	/**
	 * Convert wikitext to HTML and add it to the buffer
	 */
	function addWikiText( $text, $linestart = true ) {
		global $wgParser, $wgTitle, $wgUseTidy;

		$parserOutput = $wgParser->parse( $text, $wgTitle, $this->mParserOptions, $linestart );
		$this->mLanguageLinks += $parserOutput->getLanguageLinks();
		$this->mCategoryLinks += $parserOutput->getCategoryLinks();
		$this->addHTML( $parserOutput->getText() );
	}

	/**
	 * 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
	 */
	function addPrimaryWikiText( $text, $cacheArticle ) {
		global $wgParser, $wgParserCache, $wgUser, $wgTitle, $wgUseTidy;

		$parserOutput = $wgParser->parse( $text, $wgTitle, $this->mParserOptions, true );

		$text = $parserOutput->getText();
		
		if ( $cacheArticle ) {
			$wgParserCache->save( $parserOutput, $cacheArticle, $wgUser );
		}

		$this->mLanguageLinks += $parserOutput->getLanguageLinks();
		$this->mCategoryLinks += $parserOutput->getCategoryLinks();
		$this->addHTML( $text );
	}

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

	/**
	 * Parse wikitext and return the HTML. This is for special pages that add the text later
	 */
	function parse( $text, $linestart = true ) {
		global $wgParser, $wgTitle;
		$parserOutput = $wgParser->parse( $text, $wgTitle, $this->mParserOptions, $linestart );
		return $parserOutput->getText();
	}
	
	/**
	 * @param $article
	 * @param $user
	 */
	function tryParserCache( $article, $user ) {
		global $wgParserCache;
		$parserOutput = $wgParserCache->get( $article, $user );
		if ( $parserOutput !== false ) {
			$this->mLanguageLinks += $parserOutput->getLanguageLinks();
			$this->mCategoryLinks += $parserOutput->getCategoryLinks();
			$this->addHTML( $parserOutput->getText() );
			return true;
		} else {
			return false;
		}
	}

	/**
	 * Set the maximum cache time on the Squid in seconds
	 * @param $maxage
	 */
	function setSquidMaxage( $maxage ) {
		$this->mSquidMaxage = $maxage;
	}

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

	function sendCacheControl() {
		global $wgUseSquid, $wgUseESI;
		# FIXME: This header may cause trouble with some versions of Internet Explorer
		header( 'Vary: Accept-Encoding, Cookie' );
		if( $this->mEnableClientCache ) {
			if( $wgUseSquid && ! isset( $_COOKIE[ini_get( 'session.name') ] ) &&
			  ! $this->isPrintable() && $this->mSquidMaxage != 0 )
			{
				if ( $wgUseESI ) {
					# We'll purge the proxy cache explicitly, but require end user agents
					# to revalidate against the proxy on each visit.
					# Surrogate-Control controls our Squid, Cache-Control downstream caches
					wfDebug( "** proxy caching with ESI; {$this->mLastModified} **\n", false );
					# start with a shorter timeout for initial testing
					# header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
					header( 'Surrogate-Control: max-age='.$wgSquidMaxage.'+'.$this->mSquidMaxage.', content="ESI/1.0"');
					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( "** local proxy caching; {$this->mLastModified} **\n", false );
					# start with a shorter timeout for initial testing
					# header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
					header( 'Cache-Control: s-maxage='.$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( "** private caching; {$this->mLastModified} **\n", false );
				header( "Expires: -1" );
				header( "Cache-Control: private, must-revalidate, max-age=0" );
			}
			if($this->mLastModified) header( "Last-modified: {$this->mLastModified}" );
		} else {
			wfDebug( "** 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.
			header( 'Expires: -1' );
			header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
			header( 'Pragma: no-cache' );
		}
	}

	/**
	 * Finally, all the text has been munged and accumulated into
	 * the object, let's actually output it:
	 */
	function output() {
		global $wgUser, $wgLang, $wgDebugComments, $wgCookieExpiration;
		global $wgInputEncoding, $wgOutputEncoding, $wgContLanguageCode;
		global $wgDebugRedirects, $wgMimeType, $wgProfiler;

		if( $this->mDoNothing ){
			return;
		}
		$fname = 'OutputPage::output';
		wfProfileIn( $fname );
		$sk = $wgUser->getSkin();

		if ( '' != $this->mRedirect ) {
			if( substr( $this->mRedirect, 0, 4 ) != 'http' ) {
				# Standards require redirect URLs to be absolute
				global $wgServer;
				$this->mRedirect = $wgServer . $this->mRedirect;
			}
			if( $this->mRedirectCode == '301') {
				if( !$wgDebugRedirects ) {
					header("HTTP/1.1 {$this->mRedirectCode} Moved Permanently");
				}
				$this->mLastModified = wfTimestamp( TS_RFC2822 );
			}

			$this->sendCacheControl();

			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\">$url</a></p>\n";
				print "</body>\n</html>\n";
			} else {
				header( 'Location: '.$this->mRedirect );
			}
			if ( isset( $wgProfiler ) ) { wfDebug( $wgProfiler->getOutput() ); }
			return;
		}


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

		$this->transformBuffer();
		
		# Disable temporary placeholders, so that the skin produces HTML
		$sk->postParseLinkColour( false );

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

		$exp = time() + $wgCookieExpiration;
		foreach( $this->mCookies as $name => $val ) {
			setcookie( $name, $val, $exp, '/' );
		}

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

	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;
	}

	function setEncodings() {
		global $wgInputEncoding, $wgOutputEncoding;
		global $wgUser, $wgContLang;

		$wgInputEncoding = strtolower( $wgInputEncoding );

		if( $wgUser->getOption( 'altencoding' ) ) {
			$wgContLang->setAltEncoding();
			return;
		}

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

		/*
		# This code is unused anyway!
		# Commenting out. --bv 2003-11-15

		$a = explode( ",", $_SERVER['HTTP_ACCEPT_CHARSET'] );
		$best = 0.0;
		$bestset = "*";

		foreach ( $a as $s ) {
			if ( preg_match( "/(.*);q=(.*)/", $s, $m ) ) {
				$set = $m[1];
				$q = (float)($m[2]);
			} else {
				$set = $s;
				$q = 1.0;
			}
			if ( $q > $best ) {
				$bestset = $set;
				$best = $q;
			}
		}
		#if ( "*" == $bestset ) { $bestset = "iso-8859-1"; }
		if ( "*" == $bestset ) { $bestset = $wgOutputEncoding; }
		$wgOutputEncoding = strtolower( $bestset );

# Disable for now
#
		*/
		$wgOutputEncoding = $wgInputEncoding;
	}

	/**
	 * Returns a HTML comment with the elapsed time since request.
	 * This method has no side effects.
	 */
	function reportTime() {
		global $wgRequestTime;

		$now = wfTime();
		list( $usec, $sec ) = explode( ' ', $wgRequestTime );
		$start = (float)$sec + (float)$usec;
		$elapsed = $now - $start;

		# Use real server name if available, so we know which machine
		# in a server farm generated the current page.
		if ( function_exists( 'posix_uname' ) ) {
			$uname = @posix_uname();
		} else {
			$uname = false;
		}
		if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
			$hostname = $uname['nodename'];
		} else {
			# This may be a virtual server.
			$hostname = $_SERVER['SERVER_NAME'];
		}
		$com = sprintf( "<!-- Served by %s in %01.2f secs. -->",
		  $hostname, $elapsed );
		return $com;
	}

	/**
	 * Note: these arguments are keys into wfMsg(), not text!
	 */
	function errorpage( $title, $msg ) {
		global $wgTitle;

		$this->mDebugtext .= 'Original title: ' .
		  $wgTitle->getPrefixedText() . "\n";
		$this->setPageTitle( wfMsg( $title ) );
		$this->setHTMLTitle( wfMsg( 'errorpagetitle' ) );
		$this->setRobotpolicy( 'noindex,nofollow' );
		$this->setArticleRelated( false );
		$this->enableClientCache( false );
		$this->mRedirect = '';

		$this->mBodytext = '';
		$this->addHTML( '<p>' . wfMsg( $msg ) . "</p>\n" );
		$this->returnToMain( false );

		$this->output();
		wfErrorExit();
	}

	function sysopRequired() {
		global $wgUser;

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

		$sk = $wgUser->getSkin();
		$ap = $sk->makeKnownLink( wfMsgForContent( 'administrators' ), '' );
		$this->addHTML( wfMsg( 'sysoptext', $ap ) );
		$this->returnToMain();
	}

	function developerRequired() {
		global $wgUser;

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

		$sk = $wgUser->getSkin();
		$ap = $sk->makeKnownLink( wfMsgForContent( 'administrators' ), '' );
		$this->addHTML( wfMsg( 'developertext', $ap ) );
		$this->returnToMain();
	}

	function loginToUse() {
		global $wgUser, $wgTitle, $wgContLang;

		$this->setPageTitle( wfMsg( 'loginreqtitle' ) );
		$this->setHTMLTitle( wfMsg( 'errorpagetitle' ) );
		$this->setRobotpolicy( 'noindex,nofollow' );
		$this->setArticleFlag( false );
		$this->mBodytext = '';
		$this->addWikiText( wfMsg( 'loginreqtext' ) );

		# We put a comment in the .html file so a Sysop can diagnose the page the
		# user can't see.
		$this->addHTML( "\n<!--" .
						$wgContLang->getNsText( $wgTitle->getNamespace() ) .
						':' .
						$wgTitle->getDBkey() . '-->' );
		$this->returnToMain();		# Flip back to the main page after 10 seconds.
	}

	function databaseError( $fname, $sql, $error, $errno ) {
		global $wgUser, $wgCommandLineMode, $wgShowSQLErrors;

		$this->setPageTitle( wfMsgNoDB( 'databaseerror' ) );
		$this->setRobotpolicy( 'noindex,nofollow' );
		$this->setArticleRelated( false );
		$this->enableClientCache( false );
		$this->mRedirect = '';

		if( $wgShowSQLErrors ) {
			if ( $wgCommandLineMode ) {
				$msg = wfMsgNoDB( 'dberrortextcl', htmlspecialchars( $sql ),
							htmlspecialchars( $fname ), $errno, htmlspecialchars( $error ) );
			} else {
				$msg = wfMsgNoDB( 'dberrortext', htmlspecialchars( $sql ),
							htmlspecialchars( $fname ), $errno, htmlspecialchars( $error ) );
			}
		} else {
			if( $wgCommandLineMode ) {
				$msg = wfMsg( 'internalerror' );
			} else {
				$msg = htmlspecialchars( wfMsg( 'internalerror' ) );
			}
		}

		if ( $wgCommandLineMode || !is_object( $wgUser )) {
			print $msg."\n";
			wfErrorExit();
		}
		$this->mBodytext = $msg;
		$this->output();
		wfErrorExit();
	}

	function readOnlyPage( $source = null, $protected = false ) {
		global $wgUser, $wgReadOnlyFile;

		$this->setRobotpolicy( 'noindex,nofollow' );
		$this->setArticleRelated( false );

		if( $protected ) {
			$this->setPageTitle( wfMsg( 'viewsource' ) );
			$this->addWikiText( wfMsg( 'protectedtext' ) );
		} else {
			$this->setPageTitle( wfMsg( 'readonly' ) );
			$reason = file_get_contents( $wgReadOnlyFile );
			$this->addWikiText( wfMsg( 'readonlytext', $reason ) );
		}

		if( is_string( $source ) ) {
			if( strcmp( $source, '' ) == 0 ) {
				$source = wfMsg( 'noarticletext' );
			}
			$rows = $wgUser->getOption( 'rows' );
			$cols = $wgUser->getOption( 'cols' );
			$text = "\n<textarea cols='$cols' rows='$rows' readonly='readonly'>" .
				htmlspecialchars( $source ) . "\n</textarea>";
			$this->addHTML( $text );
		}

		$this->returnToMain( false );
	}

	function fatalError( $message ) {
		$this->setPageTitle( wfMsg( "internalerror" ) );
		$this->setRobotpolicy( "noindex,nofollow" );
		$this->setArticleRelated( false );
		$this->enableClientCache( false );
		$this->mRedirect = '';

		$this->mBodytext = $message;
		$this->output();
		wfErrorExit();
	}

	function unexpectedValueError( $name, $val ) {
		$this->fatalError( wfMsg( 'unexpected', $name, $val ) );
	}

	function fileCopyError( $old, $new ) {
		$this->fatalError( wfMsg( 'filecopyerror', $old, $new ) );
	}

	function fileRenameError( $old, $new ) {
		$this->fatalError( wfMsg( 'filerenameerror', $old, $new ) );
	}

	function fileDeleteError( $name ) {
		$this->fatalError( wfMsg( 'filedeleteerror', $name ) );
	}

	function fileNotFoundError( $name ) {
		$this->fatalError( wfMsg( 'filenotfound', $name ) );
	}

	/**
	 * return from error messages or notes
	 * @param $auto automatically redirect the user after 10 seconds
	 * @param $returnto page title to return to. Default is Main Page.
	 */
	function returnToMain( $auto = true, $returnto = NULL ) {
		global $wgUser, $wgOut, $wgRequest;

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

		$sk = $wgUser->getSkin();
		if ( '' == $returnto ) {
			$returnto = wfMsgForContent( 'mainpage' );
		}
		$link = $sk->makeKnownLink( $returnto, '' );

		$r = wfMsg( 'returnto', $link );
		if ( $auto ) {
			$titleObj = Title::newFromText( $returnto );
			$wgOut->addMeta( 'http:Refresh', '10;url=' . $titleObj->escapeFullURL() );
		}
		$wgOut->addHTML( "\n<p>$r</p>\n" );
	}

	/**
	 * This function takes the existing and broken links for the page
	 * and uses the first 10 of them for META keywords
	 */
	function addMetaTags () {
		global $wgLinkCache , $wgOut ;
		$good = array_keys ( $wgLinkCache->mGoodLinks ) ;
		$bad = array_keys ( $wgLinkCache->mBadLinks ) ;
		$a = array_merge ( $good , $bad ) ;
		$a = array_slice ( $a , 0 , 10 ) ; # 10 keywords max
		$a = implode ( ',' , $a ) ;
		$strip = array(
			"/<.*?" . ">/" => '',
			"/[_]/" => ' '
		);
		$a = htmlspecialchars(preg_replace(array_keys($strip), array_values($strip),$a ));

		$wgOut->addMeta ( 'KEYWORDS' , $a ) ;
	}

	/**
 	 * @private
	 */
	function headElement() {
		global $wgDocType, $wgDTD, $wgContLanguageCode, $wgOutputEncoding, $wgMimeType;
		global $wgUser, $wgContLang, $wgRequest;

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

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

		if ( "" == $this->mHTMLtitle ) {
			$this->mHTMLtitle = wfMsg( "pagetitle", $this->mPagetitle );
		}
		if( $xml ) {
			$xmlbits = "xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"$wgContLanguageCode\"";
		} else {
			$xmlbits = '';
		}
		$rtl = $wgContLang->isRTL() ? " dir='RTL'" : '';
		$ret .= "<html $xmlbits lang=\"$wgContLanguageCode\" $rtl>\n";
		$ret .= "<head>\n<title>" . htmlspecialchars( $this->mHTMLtitle ) . "</title>\n";
		array_push( $this->mMetatags, array( "http:Content-type", "$wgMimeType; charset={$wgOutputEncoding}" ) );

		$ret .= $this->getHeadLinks();
		global $wgStylePath;
		if( $this->isPrintable() ) {
			$media = '';
		} else {
			$media = "media='print'";
		}
		$printsheet = htmlspecialchars( "$wgStylePath/common/wikiprintable.css" );
		$ret .= "<link rel='stylesheet' type='text/css' $media href='$printsheet' />\n";

		$sk = $wgUser->getSkin();
		$ret .= $sk->getHeadScripts();
		$ret .= $this->mScripts;
		$ret .= $sk->getUserStyles();

		$ret .= "</head>\n";
		return $ret;
	}

	function getHeadLinks() {
		global $wgRequest, $wgStylePath;
		$ret = '';
		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';
			}
			$ret .= "<meta $a=\"{$tag[0]}\" content=\"{$tag[1]}\" />\n";
		}
		$p = $this->mRobotpolicy;
		if ( '' == $p ) { $p = 'index,follow'; }
		$ret .= "<meta name=\"robots\" content=\"$p\" />\n";

		if ( count( $this->mKeywords ) > 0 ) {
			$strip = array(
				"/<.*?" . ">/" => '',
				"/[_]/" => ' '
			);
			$ret .= "<meta name=\"keywords\" content=\"" .
			  htmlspecialchars(preg_replace(array_keys($strip), array_values($strip),implode( ",", $this->mKeywords ))) . "\" />\n";
		}
		foreach ( $this->mLinktags as $tag ) {
			$ret .= '<link';
			foreach( $tag as $attr => $val ) {
				$ret .= " $attr=\"" . htmlspecialchars( $val ) . "\"";
			}
			$ret .= " />\n";
		}
		if( $this->isSyndicated() ) {
			# FIXME: centralize the mime-type and name information in Feed.php
			$link = $wgRequest->escapeAppendQuery( 'feed=rss' );
			$ret .= "<link rel='alternate' type='application/rss+xml' title='RSS 2.0' href='$link' />\n";
			$link = $wgRequest->escapeAppendQuery( 'feed=atom' );
			$ret .= "<link rel='alternate' type='application/rss+atom' title='Atom 0.3' href='$link' />\n";
		}

		return $ret;
	}
	
	/**
	 * Run any necessary pre-output transformations on the buffer text
	 */
	function transformBuffer( $options = 0 ) {
	}


}

}

?>