The syntax is like this

~~isbn:[ISBN]~~
or
~~isbn:[ISBN]|[title]~~

change [ISBN] to whatever ISBN you want
change [title] to the book title

Like with other images, you can specify the alignment through spaces:

• ~~isbn:[ISBN] ~~ → left aligned
• ~~isbn: [ISBN] ~~ → centered
• ~~isbn: [ISBN]~~ → right aligned

• make a new file and name it syntax.php and paste this code in it and save it!
• make a directory named isbn under [dokuwiki's home]/lib/plugins
• Put the made php file in the folder made above.
• That's it.

getSort determines the order in which the plugin is executed. So, if you want to replace .* with your own syntax, you can do that be changing the getSort result to be first. – kite 2006-10-03

I still don't know what getSort function does.. :)
And my English not good enough to explain something well. If my English has some grammatical mistakes, please correct it. — kimes 2005-07-02 05:38

If this is a function that might be used a lot in your wiki, you could add a toolbar function — Ben Pollinger 2005-10-01 13:40.

In inc/toolbar.php, find:

       array(
            'type'   => 'format',
            'title'  => $lang['qb_extlink'],
            'icon'   => 'linkextern.png',
            'open'   => '[[',
            'close'  => ']]',
            'sample' => 'http://example.com|'.$lang['qb_extlink'],
            ),

After it, add:

       array(
            'type'   => 'format',
            'title'  => $lang['qb_isbn'],
            'icon'   => 'isbn.png',
            'open'   => '~~',
            'close'  => '~~',
            'sample' => 'isbn:0000000000|'.$lang['qb_isbn'],
            ),

In inc/lang/en/lang.php, find:

$lang['qb_extlink'] = 'External Link';

After it, add:

$lang['qb_isbn']  = 'ISBN Link';

Upload this image to lib/images/toolbar/ , or if it you want to show it's a link to Amazon, you could use this - but rename it to isbn.png if you do.

<?php
/**
 * ISBN Plugin: links to amazon.com and shows book cover image by ISBN
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     bektek
 */
 
if(!defined('DOKU_INC')) define('DOKU_INC',realpath(dirname(__FILE__).'/../../').'/');
if(!defined('DOKU_PLUGIN')) define('DOKU_PLUGIN',DOKU_INC.'lib/plugins/');
require_once(DOKU_PLUGIN.'syntax.php');
 
/**
 * All DokuWiki plugins to extend the parser/rendering mechanism
 * need to inherit from this class
 */
class syntax_plugin_isbn extends DokuWiki_Syntax_Plugin {
 
    /**
     * return some info
     */
    function getInfo(){
        return array(
            'author' => 'bektek',
            'email'  => 'bektek@gmail.com',
            'date'   => '2005-07-02',
            'name'   => 'ISBN Plugin',
            'desc'   => 'ISBN - link to amazon.com and show image',
            'url'    => 'http://www.dokuwiki.org/plugin:isbn',
        );
    }
 
    /**
     * What kind of syntax are we?
     */
    function getType(){
        return 'substition';
    }
 
    /**
     * Where to sort in?
     */
    function getSort(){
        return 322;
    }
 
    /**
     * Connect pattern to lexer
     */
    function connectTo($mode) {
      $this->Lexer->addSpecialPattern("~~isbn:.+?~~",$mode,'plugin_isbn');
    }
 
    /**
     * Handle the match
     */
    function handle($match, $state, $pos, &$handler){
        $match = substr($match,7,-2); // Strip markup
        $match = preg_split('/\|/u',$match,2); // Split title from URL
 
        // Check alignment
        $ralign = (bool)preg_match('/^ /',$match[0]);
        $lalign = (bool)preg_match('/ $/',$match[0]);
        if ($lalign & $ralign) $align = 'center';
        else if ($ralign)      $align = 'right';
        else if ($lalign)      $align = 'left';
        else                   $align = NULL;
 
        if (!isset($match[1])) $match[1] = NULL;
        return array(trim($match[0]),trim($match[1]),$align);
    }            
 
    /**
     * Create output
     */
    function render($mode, &$renderer, $data) {
        if($mode == 'xhtml'){
            $isbn    = $data[0]; 
            $target  = '_blank'; // You may adjust this
            $href    = 'http://www.amazon.com/exec/obidos/ISBN='.$isbn;
            $imglink = 'http://images.amazon.com/images/P/'.$isbn.'.01.MZZZZZZZ.gif';
            $title   = ($data[1] ? htmlspecialchars($data[1]) : $isbn);
            $src     = DOKU_BASE.'lib/exe/fetch.php?media='.urlencode($imglink);
 
            $renderer->doc .= '<a href="'.$href.'" target="'.$target.'" class="media" '.
                'title="'.$title.'" onclick="return svchk()" onkeypress="return svchk()">';
            $renderer->doc .= '<img src="'.$src.'" class="media'.$data[2].'" title="'.$title.'" alt="'.$title.'" />';
            $renderer->doc .= '</a>';
            return true;
        }
        return false;
    }
 
}
 
//Setup VIM: ex: et ts=4 enc=utf-8 :
?>

• I made a small change: The generated image link is now with the same attributes as other DokuWiki links.
• I just realized that in the code you allow a title to be appended after the ISBN and a pipe char. Is this the intended behavior or just a leftover from my code? – I think it could be useful so I changed the syntax description for the plugin.
• I now implemented an alignment attribute like that of images and adjusted the syntax.

— Esther Brunner 2005-07-02, 2005-07-13 14:20

• Great work. It'd be good to be able to pull more info from Amazon (author, title, price) just by giving the ISBN to the plugin. AWS would seem to enable this. Output could look like:

$Title by $Author, priced $Price

— Ben Pollinger 2005-09-30 19:16

It would be awesome if the Link could provide you with the most basic BibTex-Information, if this was possible. Have a look at this page: http://www.2ndminute.org:8080/amatex - once you provide your ISBN Number, it returns the BibTex-Code. — f 2006-12-06 11:02

Note that the JavaScript function “svchk()” no longer exists (and is now unnecessary) in DokuWiki, and does cause JavaScript errors, so it should be removed.
– todd [at] rollerorgans [dot] com 2007-02-26