yfix.net

demo 

    public function demo()
    {
        $name = preg_replace('~[^a-z0-9_-]+~ims', '', trim($_GET['page'] ?: $_GET['id']));
        if ( ! $name) {
            return _404();
        }
        $cls_assets = _class($assets);
        $all = $this->_get_assets();
        if ( ! isset($all[$name])) {
            return _404();
        }
        $content = $all[$name]['content'];
        if (is_callable($content)) {
            $content = $content($cls_assets);
        }
        asset($name);
        if (isset($content['demo'])) {
            $demo = $content['demo'];
            if (is_callable($demo)) {
                $demo = $demo();
            }
            $out[] = $demo;
        }
        $out[] = '<pre><code>' . _prepare_html(var_export($content, true)) . '</code></pre>';
        return implode('<br>' . PHP_EOL, $out);
    }

array (
  'versions' => 
  array (
    '8.0' => 
    array (
      'js' => 
      array (
        0 => '//cdnjs.cloudflare.com/ajax/libs/highlight.js/8.0/highlight.min.js',
        1 => '//cdnjs.cloudflare.com/ajax/libs/highlight.js/8.0/languages/php.min.js',
      ),
      'css' => 
      array (
        0 => '//cdnjs.cloudflare.com/ajax/libs/highlight.js/8.0/styles/railscasts.min.css',
      ),
    ),
  ),
  'cdn' => 
  array (
    'url' => '//cdnjs.cloudflare.com/ajax/libs/highlight.js/{version}/',
    'version' => '8.0',
    'js' => 
    array (
      0 => 'highlight.min.js',
      1 => 'languages/php.min.js',
    ),
    'css' => 
    array (
      0 => 'styles/railscasts.min.css',
    ),
  ),
  'add' => 
  array (
    'js' => 
    array (
      0 => 'hljs.initHighlightingOnLoad();',
    ),
    'css' => 
    array (
      0 => 'section.page-contents pre, pre.prettyprint { background-color: transparent; border: 0; font-family: inherit; font-size: inherit; font-weight: bold; }',
    ),
  ),
)