Ajax show editors message moved to the extension repository (r19556)

[mediawiki.git] / includes / Linker.php

<?php
/**
 * Split off some of the internal bits from Skin.php.
 * These functions are used for primarily page content:
 * links, embedded images, table of contents. Links are
 * also used in the skin.
 */

/**
 * For the moment, Skin is a descendent class of Linker.
 * In the future, it should probably be further split
 * so that ever other bit of the wiki doesn't have to
 * go loading up Skin to get at it.
 *
 */
class Linker {
        function __construct() {}

        /**
         * @deprecated
         */
        function postParseLinkColour( $s = NULL ) {
                return NULL;
        }

        /** @todo document */
        function getExternalLinkAttributes( $link, $text, $class='' ) {
                $link = htmlspecialchars( $link );

                $r = ($class != '') ? " class=\"$class\"" : " class=\"external\"";

                $r .= " title=\"{$link}\"";
                return $r;
        }

        function getInterwikiLinkAttributes( $link, $text, $class='' ) {
                global $wgContLang;

                $link = urldecode( $link );
                $link = $wgContLang->checkTitleEncoding( $link );
                $link = preg_replace( '/[\\x00-\\x1f]/', ' ', $link );
                $link = htmlspecialchars( $link );

                $r = ($class != '') ? " class=\"$class\"" : " class=\"external\"";

                $r .= " title=\"{$link}\"";
                return $r;
        }

        /** @todo document */
        function getInternalLinkAttributes( $link, $text, $broken = false ) {
                $link = urldecode( $link );
                $link = str_replace( '_', ' ', $link );
                $link = htmlspecialchars( $link );

                if( $broken == 'stub' ) {
                        $r = ' class="stub"';
                } else if ( $broken == 'yes' ) {
                        $r = ' class="new"';
                } else {
                        $r = '';
                }

                $r .= " title=\"{$link}\"";
                return $r;
        }

        /**
         * @param $nt Title object.
         * @param $text String: FIXME
         * @param $broken Boolean: FIXME, default 'false'.
         */
        function getInternalLinkAttributesObj( &$nt, $text, $broken = false ) {
                if( $broken == 'stub' ) {
                        $r = ' class="stub"';
                } else if ( $broken == 'yes' ) {
                        $r = ' class="new"';
                } else {
                        $r = '';
                }

                $r .= ' title="' . $nt->getEscapedText() . '"';
                return $r;
        }

        /**
         * This function is a shortcut to makeLinkObj(Title::newFromText($title),...). Do not call
         * it if you already have a title object handy. See makeLinkObj for further documentation.
         *
         * @param $title String: the text of the title
         * @param $text  String: link text
         * @param $query String: optional query part
         * @param $trail String: optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeLink( $title, $text = '', $query = '', $trail = '' ) {
                wfProfileIn( 'Linker::makeLink' );
                $nt = Title::newFromText( $title );
                if ($nt) {
                        $result = $this->makeLinkObj( Title::newFromText( $title ), $text, $query, $trail );
                } else {
                        wfDebug( 'Invalid title passed to Linker::makeLink(): "'.$title."\"\n" );
                        $result = $text == "" ? $title : $text;
                }

                wfProfileOut( 'Linker::makeLink' );
                return $result;
        }

        /**
         * This function is a shortcut to makeKnownLinkObj(Title::newFromText($title),...). Do not call
         * it if you already have a title object handy. See makeKnownLinkObj for further documentation.
         * 
         * @param $title String: the text of the title
         * @param $text  String: link text
         * @param $query String: optional query part
         * @param $trail String: optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeKnownLink( $title, $text = '', $query = '', $trail = '', $prefix = '',$aprops = '') {
                $nt = Title::newFromText( $title );
                if ($nt) {
                        return $this->makeKnownLinkObj( Title::newFromText( $title ), $text, $query, $trail, $prefix , $aprops );
                } else {
                        wfDebug( 'Invalid title passed to Linker::makeKnownLink(): "'.$title."\"\n" );
                        return $text == '' ? $title : $text;
                }
        }

        /**
         * This function is a shortcut to makeBrokenLinkObj(Title::newFromText($title),...). Do not call
         * it if you already have a title object handy. See makeBrokenLinkObj for further documentation.
         * 
         * @param string $title The text of the title
         * @param string $text Link text
         * @param string $query Optional query part
         * @param string $trail Optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeBrokenLink( $title, $text = '', $query = '', $trail = '' ) {
                $nt = Title::newFromText( $title );
                if ($nt) {
                        return $this->makeBrokenLinkObj( Title::newFromText( $title ), $text, $query, $trail );
                } else {
                        wfDebug( 'Invalid title passed to Linker::makeBrokenLink(): "'.$title."\"\n" );
                        return $text == '' ? $title : $text;
                }
        }

        /**
         * This function is a shortcut to makeStubLinkObj(Title::newFromText($title),...). Do not call
         * it if you already have a title object handy. See makeStubLinkObj for further documentation.
         * 
         * @param $title String: the text of the title
         * @param $text  String: link text
         * @param $query String: optional query part
         * @param $trail String: optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeStubLink( $title, $text = '', $query = '', $trail = '' ) {
                $nt = Title::newFromText( $title );
                if ($nt) {
                        return $this->makeStubLinkObj( Title::newFromText( $title ), $text, $query, $trail );
                } else {
                        wfDebug( 'Invalid title passed to Linker::makeStubLink(): "'.$title."\"\n" );
                        return $text == '' ? $title : $text;
                }
        }

        /**
         * Make a link for a title which may or may not be in the database. If you need to
         * call this lots of times, pre-fill the link cache with a LinkBatch, otherwise each
         * call to this will result in a DB query.
         * 
         * @param $nt     Title: the title object to make the link from, e.g. from
         *                      Title::newFromText.
         * @param $text  String: link text
         * @param $query String: optional query part
         * @param $trail String: optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         * @param $prefix String: optional prefix. As trail, only before instead of after.
         */
        function makeLinkObj( $nt, $text= '', $query = '', $trail = '', $prefix = '' ) {
                global $wgUser;
                $fname = 'Linker::makeLinkObj';
                wfProfileIn( $fname );

                # Fail gracefully
                if ( ! is_object($nt) ) {
                        # throw new MWException();
                        wfProfileOut( $fname );
                        return "<!-- ERROR -->{$prefix}{$text}{$trail}";
                }

                if ( $nt->isExternal() ) {
                        $u = $nt->getFullURL();
                        $link = $nt->getPrefixedURL();
                        if ( '' == $text ) { $text = $nt->getPrefixedText(); }
                        $style = $this->getInterwikiLinkAttributes( $link, $text, 'extiw' );

                        $inside = '';
                        if ( '' != $trail ) {
                                $m = array();
                                if ( preg_match( '/^([a-z]+)(.*)$$/sD', $trail, $m ) ) {
                                        $inside = $m[1];
                                        $trail = $m[2];
                                }
                        }
                        $t = "<a href=\"{$u}\"{$style}>{$text}{$inside}</a>";

                        wfProfileOut( $fname );
                        return $t;
                } elseif ( $nt->isAlwaysKnown() ) {
                        # Image links, special page links and self-links with fragements are always known.
                        $retVal = $this->makeKnownLinkObj( $nt, $text, $query, $trail, $prefix );
                } else {
                        wfProfileIn( $fname.'-immediate' );
                        # Work out link colour immediately
                        $aid = $nt->getArticleID() ;
                        if ( 0 == $aid ) {
                                $retVal = $this->makeBrokenLinkObj( $nt, $text, $query, $trail, $prefix );
                        } else {
                                $threshold = $wgUser->getOption('stubthreshold') ;
                                if ( $threshold > 0 ) {
                                        $dbr =& wfGetDB( DB_SLAVE );
                                        $s = $dbr->selectRow(
                                                array( 'page' ),
                                                array( 'page_len',
                                                        'page_namespace',
                                                        'page_is_redirect' ),
                                                array( 'page_id' => $aid ), $fname ) ;
                                        if ( $s !== false ) {
                                                $size = $s->page_len;
                                                if ( $s->page_is_redirect OR $s->page_namespace != NS_MAIN ) {
                                                        $size = $threshold*2 ; # Really big
                                                }
                                        } else {
                                                $size = $threshold*2 ; # Really big
                                        }
                                } else {
                                        $size = 1 ;
                                }
                                if ( $size < $threshold ) {
                                        $retVal = $this->makeStubLinkObj( $nt, $text, $query, $trail, $prefix );
                                } else {
                                        $retVal = $this->makeKnownLinkObj( $nt, $text, $query, $trail, $prefix );
                                }
                        }
                        wfProfileOut( $fname.'-immediate' );
                }
                wfProfileOut( $fname );
                return $retVal;
        }

        /**
         * Make a link for a title which definitely exists. This is faster than makeLinkObj because
         * it doesn't have to do a database query. It's also valid for interwiki titles and special
         * pages.
         *
         * @param $nt Title object of target page
         * @param $text   String: text to replace the title
         * @param $query  String: link target
         * @param $trail  String: text after link
         * @param $prefix String: text before link text
         * @param $aprops String: extra attributes to the a-element
         * @param $style  String: style to apply - if empty, use getInternalLinkAttributesObj instead
         * @return the a-element
         */
        function makeKnownLinkObj( $nt, $text = '', $query = '', $trail = '', $prefix = '' , $aprops = '', $style = '' ) {

                $fname = 'Linker::makeKnownLinkObj';
                wfProfileIn( $fname );

                if ( !is_object( $nt ) ) {
                        wfProfileOut( $fname );
                        return $text;
                }

                $u = $nt->escapeLocalURL( $query );
                if ( $nt->getFragment() != '' ) {
                        if( $nt->getPrefixedDbkey() == '' ) {
                                $u = '';
                                if ( '' == $text ) {
                                        $text = htmlspecialchars( $nt->getFragment() );
                                }
                        }
                        $u .= $nt->getFragmentForURL();
                }
                if ( $text == '' ) {
                        $text = htmlspecialchars( $nt->getPrefixedText() );
                }
                if ( $style == '' ) {
                        $style = $this->getInternalLinkAttributesObj( $nt, $text );
                }

                if ( $aprops !== '' ) $aprops = ' ' . $aprops;

                list( $inside, $trail ) = Linker::splitTrail( $trail );
                $r = "<a href=\"{$u}\"{$style}{$aprops}>{$prefix}{$text}{$inside}</a>{$trail}";
                wfProfileOut( $fname );
                return $r;
        }

        /**
         * Make a red link to the edit page of a given title.
         * 
         * @param $title String: The text of the title
         * @param $text  String: Link text
         * @param $query String: Optional query part
         * @param $trail String: Optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeBrokenLinkObj( $nt, $text = '', $query = '', $trail = '', $prefix = '' ) {
                # Fail gracefully
                if ( ! isset($nt) ) {
                        # throw new MWException();
                        return "<!-- ERROR -->{$prefix}{$text}{$trail}";
                }

                $fname = 'Linker::makeBrokenLinkObj';
                wfProfileIn( $fname );

                if ( '' == $query ) {
                        $q = 'action=edit';
                } else {
                        $q = 'action=edit&'.$query;
                }
                $u = $nt->escapeLocalURL( $q );

                if ( '' == $text ) {
                        $text = htmlspecialchars( $nt->getPrefixedText() );
                }
                $style = $this->getInternalLinkAttributesObj( $nt, $text, "yes" );

                list( $inside, $trail ) = Linker::splitTrail( $trail );
                $s = "<a href=\"{$u}\"{$style}>{$prefix}{$text}{$inside}</a>{$trail}";

                wfProfileOut( $fname );
                return $s;
        }

        /**
         * Make a brown link to a short article.
         * 
         * @param $title String: the text of the title
         * @param $text  String: link text
         * @param $query String: optional query part
         * @param $trail String: optional trail. Alphabetic characters at the start of this string will
         *                      be included in the link text. Other characters will be appended after
         *                      the end of the link.
         */
        function makeStubLinkObj( $nt, $text = '', $query = '', $trail = '', $prefix = '' ) {
                $u = $nt->escapeLocalURL( $query );

                if ( '' == $text ) {
                        $text = htmlspecialchars( $nt->getPrefixedText() );
                }
                $style = $this->getInternalLinkAttributesObj( $nt, $text, 'stub' );

                list( $inside, $trail ) = Linker::splitTrail( $trail );
                $s = "<a href=\"{$u}\"{$style}>{$prefix}{$text}{$inside}</a>{$trail}";
                return $s;
        }

        /**
         * Generate either a normal exists-style link or a stub link, depending
         * on the given page size.
         *
         * @param $size Integer
         * @param $nt Title object.
         * @param $text String
         * @param $query String
         * @param $trail String
         * @param $prefix String
         * @return string HTML of link
         */
        function makeSizeLinkObj( $size, $nt, $text = '', $query = '', $trail = '', $prefix = '' ) {
                global $wgUser;
                $threshold = intval( $wgUser->getOption( 'stubthreshold' ) );
                if( $size < $threshold ) {
                        return $this->makeStubLinkObj( $nt, $text, $query, $trail, $prefix );
                } else {
                        return $this->makeKnownLinkObj( $nt, $text, $query, $trail, $prefix );
                }
        }

        /** 
         * Make appropriate markup for a link to the current article. This is currently rendered
         * as the bold link text. The calling sequence is the same as the other make*LinkObj functions,
         * despite $query not being used.
         */
        function makeSelfLinkObj( $nt, $text = '', $query = '', $trail = '', $prefix = '' ) {
                if ( '' == $text ) {
                        $text = htmlspecialchars( $nt->getPrefixedText() );
                }
                list( $inside, $trail ) = Linker::splitTrail( $trail );
                return "<strong class=\"selflink\">{$prefix}{$text}{$inside}</strong>{$trail}";
        }

        /** @todo document */
        function fnamePart( $url ) {
                $basename = strrchr( $url, '/' );
                if ( false === $basename ) {
                        $basename = $url;
                } else {
                        $basename = substr( $basename, 1 );
                }
                return htmlspecialchars( $basename );
        }

        /** Obsolete alias */
        function makeImage( $url, $alt = '' ) {
                return $this->makeExternalImage( $url, $alt );
        }

        /** @todo document */
        function makeExternalImage( $url, $alt = '' ) {
                if ( '' == $alt ) {
                        $alt = $this->fnamePart( $url );
                }
                $s = '<img src="'.$url.'" alt="'.$alt.'" />';
                return $s;
        }

        /** @todo document */
        function makeImageLinkObj( $nt, $label, $alt, $align = '', $width = false, $height = false, $framed = false,
          $thumb = false, $manual_thumb = '', $page = null )
        {
                global $wgContLang, $wgUser, $wgThumbLimits, $wgGenerateThumbnailOnParse;

                $img   = new Image( $nt );

                if ( ! is_null( $page ) ) {
                        $img->selectPage( $page );
                }

                if ( !$img->allowInlineDisplay() && $img->exists() ) {
                        return $this->makeKnownLinkObj( $nt );
                }

                $url   = $img->getViewURL();
                $error = $prefix = $postfix = '';

                wfDebug( "makeImageLinkObj: '$width'x'$height', \"$label\"\n" );

                if ( 'center' == $align )
                {
                        $prefix  = '<div class="center">';
                        $postfix = '</div>';
                        $align   = 'none';
                }

                if ( $thumb || $framed ) {

                        # Create a thumbnail. Alignment depends on language
                        # writing direction, # right aligned for left-to-right-
                        # languages ("Western languages"), left-aligned
                        # for right-to-left-languages ("Semitic languages")
                        #
                        # If  thumbnail width has not been provided, it is set
                        # to the default user option as specified in Language*.php
                        if ( $align == '' ) {
                                $align = $wgContLang->isRTL() ? 'left' : 'right';
                        }


                        if ( $width === false ) {
                                $wopt = $wgUser->getOption( 'thumbsize' );

                                if( !isset( $wgThumbLimits[$wopt] ) ) {
                                         $wopt = User::getDefaultOption( 'thumbsize' );
                                }

                                $width = min( $img->getWidth(), $wgThumbLimits[$wopt] );
                        }

                        return $prefix.$this->makeThumbLinkObj( $img, $label, $alt, $align, $width, $height, $framed, $manual_thumb ).$postfix;
                }

                if ( $width && $img->exists() ) {

                        # Create a resized image, without the additional thumbnail
                        # features

                        if ( $height == false )
                                $height = -1;
                        if ( $manual_thumb == '') {
                                $thumb = $img->getThumbnail( $width, $height, $wgGenerateThumbnailOnParse );
                                if ( $thumb ) {
                                        // In most cases, $width = $thumb->width or $height = $thumb->height.
                                        // If not, we're scaling the image larger than it can be scaled,
                                        // so we send to the browser a smaller thumbnail, and let the client do the scaling.

                                        if ($height != -1 && $width > $thumb->width * $height / $thumb->height) {
                                                // $height is the limiting factor, not $width
                                                // set $width to the largest it can be, such that the resulting
                                                // scaled height is at most $height
                                                $width = floor($thumb->width * $height / $thumb->height);
                                        }
                                        $height = round($thumb->height * $width / $thumb->width);

                                        wfDebug( "makeImageLinkObj: client-size set to '$width x $height'\n" );
                                        $url = $thumb->getUrl();
                                } else {
                                        $error = htmlspecialchars( $img->getLastError() );
                                        // Do client-side scaling...
                                        $height = intval( $img->getHeight() * $width / $img->getWidth() );
                                }
                        }
                } else {
                        $width = $img->width;
                        $height = $img->height;
                }

                wfDebug( "makeImageLinkObj2: '$width'x'$height'\n" );
                $u = $nt->escapeLocalURL();
                if ( $error ) {
                        $s = $error;
                } elseif ( $url == '' ) {
                        $s = $this->makeBrokenImageLinkObj( $img->getTitle() );
                        //$s .= "<br />{$alt}<br />{$url}<br />\n";
                } else {
                        $s = '<a href="'.$u.'" class="image" title="'.$alt.'">' .
                                 '<img src="'.$url.'" alt="'.$alt.'" ' .
                                 ( $width
                                        ? ( 'width="'.$width.'" height="'.$height.'" ' )
                                        : '' ) .
                                 'longdesc="'.$u.'" /></a>';
                }
                if ( '' != $align ) {
                        $s = "<div class=\"float{$align}\"><span>{$s}</span></div>";
                }
                return str_replace("\n", ' ',$prefix.$s.$postfix);
        }

        /**
         * Make HTML for a thumbnail including image, border and caption
         * $img is an Image object
         */
        function makeThumbLinkObj( $img, $label = '', $alt, $align = 'right', $boxwidth = 180, $boxheight=false, $framed=false , $manual_thumb = "" ) {
                global $wgStylePath, $wgContLang, $wgGenerateThumbnailOnParse;
                $thumbUrl = '';
                $error = '';

                $width = $height = 0;
                if ( $img->exists() ) {
                        $width  = $img->getWidth();
                        $height = $img->getHeight();
                }
                if ( 0 == $width || 0 == $height ) {
                        $width = $height = 180;
                }
                if ( $boxwidth == 0 ) {
                        $boxwidth = 180;
                }
                if ( $framed ) {
                        // Use image dimensions, don't scale
                        $boxwidth  = $width;
                        $boxheight = $height;
                        $thumbUrl  = $img->getViewURL();
                } else {
                        if ( $boxheight === false )
                                $boxheight = -1;
                        if ( '' == $manual_thumb ) {
                                $thumb = $img->getThumbnail( $boxwidth, $boxheight, $wgGenerateThumbnailOnParse );
                                if ( $thumb ) {
                                        $thumbUrl = $thumb->getUrl();
                                        $boxwidth = $thumb->width;
                                        $boxheight = $thumb->height;
                                } else {
                                        $error = $img->getLastError();
                                }
                        }
                }
                $oboxwidth = $boxwidth + 2;

                if ( $manual_thumb != '' ) # Use manually specified thumbnail
                {
                        $manual_title = Title::makeTitleSafe( NS_IMAGE, $manual_thumb ); #new Title ( $manual_thumb ) ;
                        if( $manual_title ) {
                                $manual_img = new Image( $manual_title );
                                $thumbUrl = $manual_img->getViewURL();
                                if ( $manual_img->exists() )
                                {
                                        $width  = $manual_img->getWidth();
                                        $height = $manual_img->getHeight();
                                        $boxwidth = $width ;
                                        $boxheight = $height ;
                                        $oboxwidth = $boxwidth + 2 ;
                                }
                        }
                }

                $u = $img->getEscapeLocalURL();

                $more = htmlspecialchars( wfMsg( 'thumbnail-more' ) );
                $magnifyalign = $wgContLang->isRTL() ? 'left' : 'right';
                $textalign = $wgContLang->isRTL() ? ' style="text-align:right"' : '';

                $s = "<div class=\"thumb t{$align}\"><div class=\"thumbinner\" style=\"width:{$oboxwidth}px;\">";
                if( $thumbUrl == '' ) {
                        // Couldn't generate thumbnail? Scale the image client-side.
                        $thumbUrl = $img->getViewURL();
                        if( $boxheight == -1 ) {
                                // Approximate...
                                $boxheight = intval( $height * $boxwidth / $width );
                        }
                }
                if ( $error ) {
                        $s .= htmlspecialchars( $error );
                        $zoomicon = '';
                } elseif( !$img->exists() ) {
                        $s .= $this->makeBrokenImageLinkObj( $img->getTitle() );
                        $zoomicon = '';
                } else {
                        $s .= '<a href="'.$u.'" class="internal" title="'.$alt.'">'.
                                '<img src="'.$thumbUrl.'" alt="'.$alt.'" ' .
                                'width="'.$boxwidth.'" height="'.$boxheight.'" ' .
                                'longdesc="'.$u.'" class="thumbimage" /></a>';
                        if ( $framed ) {
                                $zoomicon="";
                        } else {
                                $zoomicon =  '<div class="magnify" style="float:'.$magnifyalign.'">'.
                                        '<a href="'.$u.'" class="internal" title="'.$more.'">'.
                                        '<img src="'.$wgStylePath.'/common/images/magnify-clip.png" ' .
                                        'width="15" height="11" alt="" /></a></div>';
                        }
                }
                $s .= '  <div class="thumbcaption"'.$textalign.'>'.$zoomicon.$label."</div></div></div>";
                return str_replace("\n", ' ', $s);
        }

        /**
         * Pass a title object, not a title string
         */
        function makeBrokenImageLinkObj( $nt, $text = '', $query = '', $trail = '', $prefix = '' ) {
                # Fail gracefully
                if ( ! isset($nt) ) {
                        # throw new MWException();
                        return "<!-- ERROR -->{$prefix}{$text}{$trail}";
                }

                $fname = 'Linker::makeBrokenImageLinkObj';
                wfProfileIn( $fname );

                $q = 'wpDestFile=' . urlencode( $nt->getDBkey() );
                if ( '' != $query ) {
                        $q .= "&$query";
                }
                $uploadTitle = SpecialPage::getTitleFor( 'Upload' );
                $url = $uploadTitle->escapeLocalURL( $q );

                if ( '' == $text ) {
                        $text = htmlspecialchars( $nt->getPrefixedText() );
                }
                $style = $this->getInternalLinkAttributesObj( $nt, $text, "yes" );
                list( $inside, $trail ) = Linker::splitTrail( $trail );
                $s = "<a href=\"{$url}\"{$style}>{$prefix}{$text}{$inside}</a>{$trail}";

                wfProfileOut( $fname );
                return $s;
        }

        /** @todo document */
        function makeMediaLink( $name, /* wtf?! */ $url, $alt = '' ) {
                $nt = Title::makeTitleSafe( NS_IMAGE, $name );
                return $this->makeMediaLinkObj( $nt, $alt );
        }

        /**
         * Create a direct link to a given uploaded file.
         *
         * @param $title Title object.
         * @param $text  String: pre-sanitized HTML
         * @param $nourl Boolean: Mask absolute URLs, so the parser doesn't
         *                       linkify them (it is currently not context-aware)
         * @return string HTML
         *
         * @public
         * @todo Handle invalid or missing images better.
         */
        function makeMediaLinkObj( $title, $text = '' ) {
                if( is_null( $title ) ) {
                        ### HOTFIX. Instead of breaking, return empty string.
                        return $text;
                } else {
                        $img  = new Image( $title );
                        if( $img->exists() ) {
                                $url  = $img->getURL();
                                $class = 'internal';
                        } else {
                                $upload = SpecialPage::getTitleFor( 'Upload' );
                                $url = $upload->getLocalUrl( 'wpDestFile=' . urlencode( $img->getName() ) );
                                $class = 'new';
                        }
                        $alt = htmlspecialchars( $title->getText() );
                        if( $text == '' ) {
                                $text = $alt;
                        }
                        $u = htmlspecialchars( $url );
                        return "<a href=\"{$u}\" class=\"$class\" title=\"{$alt}\">{$text}</a>";
                }
        }

        /** @todo document */
        function specialLink( $name, $key = '' ) {
                global $wgContLang;

                if ( '' == $key ) { $key = strtolower( $name ); }
                $pn = $wgContLang->ucfirst( $name );
                return $this->makeKnownLink( $wgContLang->specialPage( $pn ),
                  wfMsg( $key ) );
        }

        /** @todo document */
        function makeExternalLink( $url, $text, $escape = true, $linktype = '', $ns = null ) {
                $style = $this->getExternalLinkAttributes( $url, $text, 'external ' . $linktype );
                global $wgNoFollowLinks, $wgNoFollowNsExceptions;
                if( $wgNoFollowLinks && !(isset($ns) && in_array($ns, $wgNoFollowNsExceptions)) ) {
                        $style .= ' rel="nofollow"';
                }
                $url = htmlspecialchars( $url );
                if( $escape ) {
                        $text = htmlspecialchars( $text );
                }
                return '<a href="'.$url.'"'.$style.'>'.$text.'</a>';
        }

        /**
         * Make user link (or user contributions for unregistered users)
         * @param $userId   Integer: user id in database.
         * @param $userText String: user name in database
         * @return string HTML fragment
         * @private
         */
        function userLink( $userId, $userText ) {
                $encName = htmlspecialchars( $userText );
                if( $userId == 0 ) {
                        $contribsPage = SpecialPage::getTitleFor( 'Contributions', $userText );
                        return $this->makeKnownLinkObj( $contribsPage,
                                $encName);
                } else {
                        $userPage = Title::makeTitle( NS_USER, $userText );
                        return $this->makeLinkObj( $userPage, $encName );
                }
        }

        /**
         * @param $userId Integer: user id in database.
         * @param $userText String: user name in database.
         * @return string HTML fragment with talk and/or block links
         * @private
         */
        function userToolLinks( $userId, $userText ) {
                global $wgUser, $wgDisableAnonTalk, $wgSysopUserBans;
                $talkable = !( $wgDisableAnonTalk && 0 == $userId );
                $blockable = ( $wgSysopUserBans || 0 == $userId );

                $items = array();
                if( $talkable ) {
                        $items[] = $this->userTalkLink( $userId, $userText );
                }
                if( $userId ) {
                        // check if the user has an edit
                        if( User::edits( $userId ) == 0 ) {
                                $style = "class='new'";
                        } else {
                                $style = '';
                        }
                        $contribsPage = SpecialPage::getTitleFor( 'Contributions', $userText );
                        $items[] = $this->makeKnownLinkObj( $contribsPage ,
                                wfMsgHtml( 'contribslink' ),
                                '', '', '', '', $style
                        );
                }
                if( $blockable && $wgUser->isAllowed( 'block' ) ) {
                        $items[] = $this->blockLink( $userId, $userText );
                }

                if( $items ) {
                        return ' (' . implode( ' | ', $items ) . ')';
                } else {
                        return '';
                }
        }

        /**
         * @param $userId Integer: user id in database.
         * @param $userText String: user name in database.
         * @return string HTML fragment with user talk link
         * @private
         */
        function userTalkLink( $userId, $userText ) {
                global $wgLang;
                $talkname = $wgLang->getNsText( NS_TALK ); # use the shorter name

                $userTalkPage = Title::makeTitle( NS_USER_TALK, $userText );
                $userTalkLink = $this->makeLinkObj( $userTalkPage, $talkname );
                return $userTalkLink;
        }

        /**
         * @param $userId Integer: userid
         * @param $userText String: user name in database.
         * @return string HTML fragment with block link
         * @private
         */
        function blockLink( $userId, $userText ) {
                $blockPage = SpecialPage::getTitleFor( 'Blockip', $userText );
                $blockLink = $this->makeKnownLinkObj( $blockPage,
                        wfMsgHtml( 'blocklink' ) );
                return $blockLink;
        }
        
        /**
         * Generate a user link if the current user is allowed to view it
         * @param $rev Revision object.
         * @return string HTML
         */
        function revUserLink( $rev ) {
                if( $rev->userCan( Revision::DELETED_USER ) ) {
                        $link = $this->userLink( $rev->getRawUser(), $rev->getRawUserText() );
                } else {
                        $link = wfMsgHtml( 'rev-deleted-user' );
                }
                if( $rev->isDeleted( Revision::DELETED_USER ) ) {
                        return '<span class="history-deleted">' . $link . '</span>';
                }
                return $link;
        }

        /**
         * Generate a user tool link cluster if the current user is allowed to view it
         * @param $rev Revision object.
         * @return string HTML
         */
        function revUserTools( $rev ) {
                if( $rev->userCan( Revision::DELETED_USER ) ) {
                        $link = $this->userLink( $rev->getRawUser(), $rev->getRawUserText() ) .
                                ' ' .
                                $this->userToolLinks( $rev->getRawUser(), $rev->getRawUserText() );
                } else {
                        $link = wfMsgHtml( 'rev-deleted-user' );
                }
                if( $rev->isDeleted( Revision::DELETED_USER ) ) {
                        return '<span class="history-deleted">' . $link . '</span>';
                }
                return $link;
        }
        
        /**
         * This function is called by all recent changes variants, by the page history,
         * and by the user contributions list. It is responsible for formatting edit
         * comments. It escapes any HTML in the comment, but adds some CSS to format
         * auto-generated comments (from section editing) and formats [[wikilinks]].
         *
         * @author Erik Moeller <moeller@scireview.de>
         *
         * Note: there's not always a title to pass to this function.
         * Since you can't set a default parameter for a reference, I've turned it
         * temporarily to a value pass. Should be adjusted further. --brion
         *
         * $param string $comment
         * @param mixed $title Title object (to generate link to the section in autocomment) or null
         * @param bool $local Whether section links should refer to local page
         */
        function formatComment($comment, $title = NULL, $local = false) {
                wfProfileIn( __METHOD__ );

                global $wgContLang;
                $comment = str_replace( "\n", " ", $comment );
                $comment = htmlspecialchars( $comment );

                # The pattern for autogen comments is / * foo * /, which makes for
                # some nasty regex.
                # We look for all comments, match any text before and after the comment,
                # add a separator where needed and format the comment itself with CSS
                $match = array();
                while (preg_match('/(.*)\/\*\s*(.*?)\s*\*\/(.*)/', $comment,$match)) {
                        $pre=$match[1];
                        $auto=$match[2];
                        $post=$match[3];
                        $link='';
                        if( $title ) {
                                $section = $auto;

                                # Generate a valid anchor name from the section title.
                                # Hackish, but should generally work - we strip wiki
                                # syntax, including the magic [[: that is used to
                                # "link rather than show" in case of images and
                                # interlanguage links.
                                $section = str_replace( '[[:', '', $section );
                                $section = str_replace( '[[', '', $section );
                                $section = str_replace( ']]', '', $section );
                                if ( $local ) {
                                        $sectionTitle = Title::newFromText( '#' . $section);
                                } else {
                                        $sectionTitle = wfClone( $title );
                                        $sectionTitle->mFragment = $section;
                                }
                                $link = $this->makeKnownLinkObj( $sectionTitle, wfMsg( 'sectionlink' ) );
                        }
                        $sep='-';
                        $auto=$link.$auto;
                        if($pre) { $auto = $sep.' '.$auto; }
                        if($post) { $auto .= ' '.$sep; }
                        $auto='<span class="autocomment">'.$auto.'</span>';
                        $comment=$pre.$auto.$post;
                }

                # format regular and media links - all other wiki formatting
                # is ignored
                $medians = '(?:' . preg_quote( Namespace::getCanonicalName( NS_MEDIA ), '/' ) . '|';
                $medians .= preg_quote( $wgContLang->getNsText( NS_MEDIA ), '/' ) . '):';
                while(preg_match('/\[\[:?(.*?)(\|(.*?))*\]\](.*)$/',$comment,$match)) {
                        # Handle link renaming [[foo|text]] will show link as "text"
                        if( "" != $match[3] ) {
                                $text = $match[3];
                        } else {
                                $text = $match[1];
                        }
                        $submatch = array();
                        if( preg_match( '/^' . $medians . '(.*)$/i', $match[1], $submatch ) ) {
                                # Media link; trail not supported.
                                $linkRegexp = '/\[\[(.*?)\]\]/';
                                $thelink = $this->makeMediaLink( $submatch[1], "", $text );
                        } else {
                                # Other kind of link
                                if( preg_match( $wgContLang->linkTrail(), $match[4], $submatch ) ) {
                                        $trail = $submatch[1];
                                } else {
                                        $trail = "";
                                }
                                $linkRegexp = '/\[\[(.*?)\]\]' . preg_quote( $trail, '/' ) . '/';
                                if (isset($match[1][0]) && $match[1][0] == ':')
                                        $match[1] = substr($match[1], 1);
                                $thelink = $this->makeLink( $match[1], $text, "", $trail );
                        }
                        $comment = preg_replace( $linkRegexp, StringUtils::escapeRegexReplacement( $thelink ), $comment, 1 );
                }
                wfProfileOut( __METHOD__ );
                return $comment;
        }

        /**
         * Wrap a comment in standard punctuation and formatting if
         * it's non-empty, otherwise return empty string.
         *
         * @param string $comment
         * @param mixed $title Title object (to generate link to section in autocomment) or null
         * @param bool $local Whether section links should refer to local page
         *
         * @return string
         */
        function commentBlock( $comment, $title = NULL, $local = false ) {
                // '*' used to be the comment inserted by the software way back
                // in antiquity in case none was provided, here for backwards
                // compatability, acc. to brion -ævar
                if( $comment == '' || $comment == '*' ) {
                        return '';
                } else {
                        $formatted = $this->formatComment( $comment, $title, $local );
                        return " <span class=\"comment\">($formatted)</span>";
                }
        }
        
        /**
         * Wrap and format the given revision's comment block, if the current
         * user is allowed to view it.
         *
         * @param Revision $rev
         * @param bool $local Whether section links should refer to local page
         * @return string HTML
         */
        function revComment( Revision $rev, $local = false ) {
                if( $rev->userCan( Revision::DELETED_COMMENT ) ) {
                        $block = $this->commentBlock( $rev->getRawComment(), $rev->getTitle(), $local );
                } else {
                        $block = " <span class=\"comment\">" .
                                wfMsgHtml( 'rev-deleted-comment' ) . "</span>";
                }
                if( $rev->isDeleted( Revision::DELETED_COMMENT ) ) {
                        return " <span class=\"history-deleted\">$block</span>";
                }
                return $block;
        }

        /** @todo document */
        function tocIndent() {
                return "\n<ul>";
        }

        /** @todo document */
        function tocUnindent($level) {
                return "</li>\n" . str_repeat( "</ul>\n</li>\n", $level>0 ? $level : 0 );
        }

        /**
         * parameter level defines if we are on an indentation level
         */
        function tocLine( $anchor, $tocline, $tocnumber, $level ) {
                return "\n<li class=\"toclevel-$level\"><a href=\"#" .
                        $anchor . '"><span class="tocnumber">' .
                        $tocnumber . '</span> <span class="toctext">' .
                        $tocline . '</span></a>';
        }

        /** @todo document */
        function tocLineEnd() {
                return "</li>\n";
        }

        /** @todo document */
        function tocList($toc) {
                global $wgJsMimeType;
                $title =  wfMsgForContent('toc') ;
                return
                   '<table id="toc" class="toc" summary="' . $title .'"><tr><td>'
                 . '<div id="toctitle"><h2>' . $title . "</h2></div>\n"
                 . $toc
                 # no trailing newline, script should not be wrapped in a
                 # paragraph
                 . "</ul>\n</td></tr></table>"
                 . '<script type="' . $wgJsMimeType . '">'
                 . ' if (window.showTocToggle) {'
                 . ' var tocShowText = "' . wfEscapeJsString( wfMsgForContent('showtoc') ) . '";'
                 . ' var tocHideText = "' . wfEscapeJsString( wfMsgForContent('hidetoc') ) . '";'
                 . ' showTocToggle();'
                 . ' } '
                 . "</script>\n";
        }

        /** @todo document */
        public function editSectionLinkForOther( $title, $section ) {
                global $wgContLang;

                $title = Title::newFromText( $title );
                $editurl = '&section='.$section;
                $url = $this->makeKnownLinkObj( $title, wfMsg('editsection'), 'action=edit'.$editurl );

                return "<span class=\"editsection\">[".$url."]</span>";

        }

        /**
         * @param $title Title object.
         * @param $section Integer: section number.
         * @param $hint Link String: title, or default if omitted or empty
         */
        public function editSectionLink( $nt, $section, $hint='' ) {
                global $wgContLang;

                $editurl = '&section='.$section;
                $hint = ( $hint=='' ) ? '' : ' title="' . wfMsgHtml( 'editsectionhint', htmlspecialchars( $hint ) ) . '"';
                $url = $this->makeKnownLinkObj( $nt, wfMsg('editsection'), 'action=edit'.$editurl, '', '', '',  $hint );

                return "<span class=\"editsection\">[".$url."]</span>";
        }

        /**
         * Create a headline for content
         *
         * @param int    $level   The level of the headline (1-6)
         * @param string $attribs Any attributes for the headline, starting with a space and ending with '>'
         *                        This *must* be at least '>' for no attribs
         * @param string $anchor  The anchor to give the headline (the bit after the #)
         * @param string $text    The text of the header
         * @param string $link    HTML to add for the section edit link
         *
         * @return string HTML headline
         */
        public function makeHeadline( $level, $attribs, $anchor, $text, $link ) {
                return "<a name=\"$anchor\"></a><h$level$attribs$link <span class=\"mw-headline\">$text</span></h$level>";
        }

        /**
         * Split a link trail, return the "inside" portion and the remainder of the trail
         * as a two-element array
         *
         * @static
         */
        static function splitTrail( $trail ) {
                static $regex = false;
                if ( $regex === false ) {
                        global $wgContLang;
                        $regex = $wgContLang->linkTrail();
                }
                $inside = '';
                if ( '' != $trail ) {
                        $m = array();
                        if ( preg_match( $regex, $trail, $m ) ) {
                                $inside = $m[1];
                                $trail = $m[2];
                        }
                }
                return array( $inside, $trail );
        }

        /**
         * Generate a rollback link for a given revision.  Currently it's the
         * caller's responsibility to ensure that the revision is the top one. If
         * it's not, of course, the user will get an error message.
         *
         * If the calling page is called with the parameter &bot=1, all rollback
         * links also get that parameter. It causes the edit itself and the rollback
         * to be marked as "bot" edits. Bot edits are hidden by default from recent
         * changes, so this allows sysops to combat a busy vandal without bothering
         * other users.
         *
         * @param Revision $rev
         */
        function generateRollback( $rev ) {
                global $wgUser, $wgRequest;
                $title = $rev->getTitle();

                $extraRollback = $wgRequest->getBool( 'bot' ) ? '&bot=1' : '';
                $extraRollback .= '&token=' . urlencode(
                        $wgUser->editToken( array( $title->getPrefixedText(), $rev->getUserText() ) ) );
                return '<span class="mw-rollback-link">['. $this->makeKnownLinkObj( $title,
                        wfMsg('rollbacklink'),
                        'action=rollback&from=' . urlencode( $rev->getUserText() ) . $extraRollback ) .']</span>';
        }

        /**
         * Returns HTML for the "templates used on this page" list.
         *
         * @param array $templates Array of templates from Article::getUsedTemplate
         * or similar
         * @param bool $preview Whether this is for a preview
         * @param bool $section Whether this is for a section edit
         * @return string HTML output
         */
        public function formatTemplates( $templates, $preview = false, $section = false) {
                global $wgUser;
                wfProfileIn( __METHOD__ );

                $sk =& $wgUser->getSkin();

                $outText = '';
                if ( count( $templates ) > 0 ) {
                        # Do a batch existence check
                        $batch = new LinkBatch;
                        foreach( $templates as $title ) {
                                $batch->addObj( $title );
                        }
                        $batch->execute();

                        # Construct the HTML
                        $outText = '<div class="mw-templatesUsedExplanation">';
                        if ( $preview ) {
                                $outText .= wfMsgExt( 'templatesusedpreview', array( 'parse' ) );
                        } elseif ( $section ) {
                                $outText .= wfMsgExt( 'templatesusedsection', array( 'parse' ) );
                        } else {
                                $outText .= wfMsgExt( 'templatesused', array( 'parse' ) );
                        }
                        $outText .= '</div><ul>';

                        foreach ( $templates as $titleObj ) {
                                $r = $titleObj->getRestrictions( 'edit' );
                                if ( in_array( 'sysop', $r ) ) { 
                                        $protected = wfMsgExt( 'template-protected', array( 'parseinline' ) );
                                } elseif ( in_array( 'autoconfirmed', $r ) ) {
                                        $protected = wfMsgExt( 'template-semiprotected', array( 'parseinline' ) );
                                } else {
                                        $protected = '';
                                }
                                $outText .= '<li>' . $sk->makeLinkObj( $titleObj ) . ' ' . $protected . '</li>';
                        }
                        $outText .= '</ul>';
                }
                wfProfileOut( __METHOD__  );
                return $outText;
        }
        
        /**
         * Format a size in bytes for output, using an appropriate
         * unit (B, KB, MB or GB) according to the magnitude in question
         *
         * @param $size Size to format
         * @return string
         */
        public function formatSize( $size ) {
                global $wgLang;
                if( $size > 1024 ) {
                        $size = $size / 1024;
                        if( $size > 1024 ) {
                                $size = $size / 1024;
                                if( $size > 1024 ) {
                                        $size = $size / 1024;
                                        $msg = 'size-gigabytes';
                                } else {
                                        $msg = 'size-megabytes';
                                }
                        } else {
                                $msg = 'size-kilobytes';
                        }
                } else {
                        $msg = 'size-bytes';
                }
                $size = round( $size, 0 );
                return wfMsgHtml( $msg, $wgLang->formatNum( $size ) );
        }

        /**
         * Given the id of an interface element, constructs the appropriate title
         * and accesskey attributes from the system messages.  (Note, this is usu-
         * ally the id but isn't always, because sometimes the accesskey needs to
         * go on a different element than the id, for reverse-compatibility, etc.)
         *
         * @param string $name Id of the element, minus prefixes.
         * @return string title and accesskey attributes, ready to drop in an
         *   element (e.g., ' title="This does something [x]" accesskey="x"').
         */
        public function tooltipAndAccesskey($name) {
                $out = '';

                $tooltip = wfMsg('tooltip-'.$name);
                if (!wfEmptyMsg('tooltip-'.$name, $tooltip) && $tooltip != '-') {
                        // Compatibility: formerly some tooltips had [alt-.] hardcoded
                        $tooltip = preg_replace( "/ ?\[alt-.\]$/", '', $tooltip );
                        $out .= ' title="'.htmlspecialchars($tooltip);
                }
                $accesskey = wfMsg('accesskey-'.$name);
                if ($accesskey && $accesskey != '-' && !wfEmptyMsg('accesskey-'.$name, $accesskey)) {
                        if ($out) $out .= " [$accesskey]\" accesskey=\"$accesskey\"";
                        else $out .= " title=\"[$accesskey]\" accesskey=\"$accesskey\"";
                } elseif ($out) {
                        $out .= '"';
                }
                return $out;
        }

        /**
         * Given the id of an interface element, constructs the appropriate title
         * attribute from the system messages.  (Note, this is usually the id but
         * isn't always, because sometimes the accesskey needs to go on a different
         * element than the id, for reverse-compatibility, etc.)
         *
         * @param string $name Id of the element, minus prefixes.
         * @return string title attribute, ready to drop in an element
         * (e.g., ' title="This does something"').
         */
        public function tooltip($name) {
                $out = '';

                $tooltip = wfMsg('tooltip-'.$name);
                if (!wfEmptyMsg('tooltip-'.$name, $tooltip) && $tooltip != '-') {
                        $out = ' title="'.htmlspecialchars($tooltip).'"';
                }

                return $out;
        }
}

?>