markdown Template Extension for F3

index.php

\Template::instance()->extend('markdown', '\ViewHelper::renderMarkdown');

$f3->route('GET /test', function($f3) { 

  $f3->set('str','## foo');
  $f3->set('mdFile','path/to/readme.md');  

	echo \Template::instance()->render('test.html');

 });

test.html

<markdown>
## headlines are cool
</markdown>

<markdown>{{@str}}</markdown>

<markdown src="{{@mdFile}}"></markdown>

<markdown>
**basepath** is: {{@BASE}}
</markdown>

viewhelper.php

class ViewHelper {   

   static function renderMarkdown($args)
    {
        $tmp = \Template::instance();
        $md_string = (isset($args[0])) ? '"'.addslashes($tmp->token($args[0])).'"' : '';
        if (array_key_exists('@attrib', $args)) {
            $attr = $args['@attrib'];
            foreach ($attr as &$att) {
                if (is_int(strpos($att, '@')))
                    $att = $tmp->token($att);
                else
                    $att = "'".$att."'";
            }
            if (array_key_exists('src', $attr))
                $md_string = 'file_exists('.$attr['src'].') ? \Base::instance()->read('.$attr['src'].') : ""';
        }
        $md = '<?php '.
            '$md_content='.$md_string.'; '.
            'echo \Markdown::instance()->convert($md_content);'.
            ' ?>';
        return $md;
    }
}