If you are using Gallery plugin, you can have lightbox effects on your images with a little effort.

Gallery plugin has PrettyPhoto library already. So if you change few lines of source code of dokuwiki parser, You can have PrettyPhoto.

If you upgrade your DokuWiki, these changes will be overwritten. So you must do them again

• go to installation folder of your dokuwiki and find xhtml.php at inc/parser/xhtml.php.
• find function internalmedia
• delete or remark the line 1077

$link['url'] = ml($src, array('id' => $ID, 'cache' => $cache, 'rev'=>$this->_getLastMediaRevisionAt($src)), ($linking == 'direct'));

• and insert two lines there.

/* gallery lightbox */ $link['url']= ml($src,array('cache'=>$cache));
/* gallery lightbox */ $link['rel']="lightbox[".$ID."]";                 

The final result is

    /**
     * Render an internal media file
     *
     * @param string $src       media ID
     * @param string $title     descriptive text
     * @param string $align     left|center|right
     * @param int    $width     width of media in pixel
     * @param int    $height    height of media in pixel
     * @param string $cache     cache|recache|nocache
     * @param string $linking   linkonly|detail|nolink
     * @param bool   $return    return HTML instead of adding to $doc
     * @return void|string
     */
    function internalmedia($src, $title = null, $align = null, $width = null,
                           $height = null, $cache = null, $linking = null, $return = false) {
        global $ID;
        list($src, $hash) = explode('#', $src, 2);
        resolve_mediaid(getNS($ID), $src, $exists, $this->date_at, true);
 
        $noLink = false;
        $render = ($linking == 'linkonly') ? false : true;
        $link   = $this->_getMediaLinkConf($src, $title, $align, $width, $height, $cache, $render);
 
        list($ext, $mime) = mimetype($src, false);
        if(substr($mime, 0, 5) == 'image' && $render) {
            // $link['url'] = ml($src, array('id' => $ID, 'cache' => $cache, 'rev'=>$this->_getLastMediaRevisionAt($src)), ($linking == 'direct'));
            /* gallery lightbox */ $link['url']    = ml($src,array('cache'=>$cache));  //추가 vaslor
            /* gallery lightbox */ $link['rel']="lightbox[".$ID."]";                  //추가 vaslor
        } elseif(($mime == 'application/x-shockwave-flash' || media_supportedav($mime)) && $render) {
            // don't link movies
            $noLink = true;
        } else {
            // add file icons
            $class = preg_replace('/[^_\-a-z0-9]+/i', '_', $ext);
            $link['class'] .= ' mediafile mf_'.$class;
            $link['url'] = ml($src, array('id' => $ID, 'cache' => $cache , 'rev'=>$this->_getLastMediaRevisionAt($src)), true);
            if($exists) $link['title'] .= ' ('.filesize_h(filesize(mediaFN($src))).')';
        }
 
        if($hash) $link['url'] .= '#'.$hash;
 
        //markup non existing files
        if(!$exists) {
            $link['class'] .= ' wikilink2';
        }
 
        //output formatted
        if($return) {
            if($linking == 'nolink' || $noLink) return $link['name'];
            else return $this->_formatLink($link);
        } else {
            if($linking == 'nolink' || $noLink) $this->doc .= $link['name'];
            else $this->doc .= $this->_formatLink($link);
        }
    }

you can do same thing with external image.

• find function externalmedia
• just insert one line. no deletion.

  /* gallery lightbox */ $link['rel']="lightbox[".$ID."]";  // 추가.. vaslor

    /**
     * Render an external media file
     *
     * @param string $src     full media URL
     * @param string $title   descriptive text
     * @param string $align   left|center|right
     * @param int    $width   width of media in pixel
     * @param int    $height  height of media in pixel
     * @param string $cache   cache|recache|nocache
     * @param string $linking linkonly|detail|nolink
     * @param bool   $return  return HTML instead of adding to $doc
     */
    function externalmedia($src, $title = null, $align = null, $width = null,
                           $height = null, $cache = null, $linking = null, $return = false) {
        list($src, $hash) = explode('#', $src, 2);
        $noLink = false;
        $render = ($linking == 'linkonly') ? false : true;
        $link   = $this->_getMediaLinkConf($src, $title, $align, $width, $height, $cache, $render);
 
        $link['url'] = ml($src, array('cache' => $cache));
 
        list($ext, $mime) = mimetype($src, false);
        if(substr($mime, 0, 5) == 'image' && $render) {
            // link only jpeg images
            // if ($ext != 'jpg' && $ext != 'jpeg') $noLink = true;
            /* gallery lightbox */ $link['rel']="lightbox[".$ID."]";  // 추가.. vaslor
        } elseif(($mime == 'application/x-shockwave-flash' || media_supportedav($mime)) && $render) {
            // don't link movies
            $noLink = true;
        } else {
            // add file icons
            $class = preg_replace('/[^_\-a-z0-9]+/i', '_', $ext);
            $link['class'] .= ' mediafile mf_'.$class;
        }
 
        if($hash) $link['url'] .= '#'.$hash;
 
        //output formatted
        if($return) {
            if($linking == 'nolink' || $noLink) return $link['name'];
            else return $this->_formatLink($link);
        } else {
            if($linking == 'nolink' || $noLink) $this->doc .= $link['name'];
            else $this->doc .= $this->_formatLink($link);
        }
    }

Why?

• To decide which image will have lightbox slideshow
• Group together images into slideshow on one page as you like

How?

• Apply new internal image hash parameter ss [:slide-show:]
• Grouping is done by the value of ss parametter which is number and it is mandatory

E.g.

{{imagefile1.jpg#ss=1?640x480}} <- Slideshow group #1
{{imagefile2.jpg#ss=1?640x480}} <- Slideshow group #1
{{imagefile3.jpg#ss=2?640x480}} <- Slideshow group #2
{{imagefile4.jpg#ss=2?640x480}} <- Slideshow group #2
{{imagefile5.jpg?640x480}} <- Image without slideshow! :)

Notice that all hash parameters started by # sign are right after the filename and before the regular image link parameters, before the ? symbol!

How to implement this adjustment?

• Find file inc/parser/xhtml.php
• Find function internalmedia()
• Find this line:

$link['url'] = ml($src, array('id' => $ID, 'cache' => $cache, 'rev'=>$this->_getLastMediaRevisionAt($src)), ($linking == 'direct'));

• Insert 8 new lines before line above:

// activate lightbox slideshow group by #ss=1
if (!is_null(plugin_load('syntax', 'gallery'))) {
    $match = array();
    if (preg_match('/(?:^|(?<=&))ss=(\d+)(?:(?=&)|$)/', $hash, $match)) {
        $linking = 'direct';
        $link['rel'] = 'lightbox[gal-'.substr(md5($ID.'#ss='.$match[1]),4).']';
    }
}

Patch for DokuWiki version 2015-08-10a:

xhtml.php.patch

--- dokuwiki-old/inc/parser/xhtml.php   2015-08-23 15:57:26.000000000 +0200
+++ dokuwiki/inc/parser/xhtml.php   2016-08-04 15:30:31.732748953 +0200
@@ -1117,6 +1117,14 @@
 
         list($ext, $mime) = mimetype($src, false);
         if(substr($mime, 0, 5) == 'image' && $render) {
+            // activate lightbox slideshow group by #ss=1
+            if (!is_null(plugin_load('syntax', 'gallery'))) {
+                $match = array();
+                if (preg_match('/(?:^|(?<=&))ss=(\d+)(?:(?=&)|$)/', $hash, $match)) {
+                    $linking = 'direct';
+                    $link['rel'] = 'lightbox[gal-'.substr(md5($ID.'#ss='.$match[1]),4).']';
+                }
+            }
             $link['url'] = ml($src, array('id' => $ID, 'cache' => $cache, 'rev'=>$this->_getLastMediaRevisionAt($src)), ($linking == 'direct'));
         } elseif(($mime == 'application/x-shockwave-flash' || media_supportedav($mime)) && $render) {
             // don't link movies