Extending the concept of renderable components so that the rendering methods can be organized into hierarchies

gistfile1.aw

    /**
     * Tries to render the given widget or delegates the task to the parent renderer
     *
     * In order to be able to render the given widget, this renderer must implement
     * a protected method called render_widgetname() where widgetname is the name of
     * the widget's class or some of its parents. The rendering method is supposed
     * to accept the single parameter - the renderable widget itself.
     *
     * @param renderable $widget some object implementing the renderable interface
     * @return string HTML code representing the widget
     */
    public function render(renderable $widget) {
        // populate the list of class names to try
        $tryclasses = array(get_class($widget));
        foreach (class_parents($widget) as $parent) {
            if (in_array('renderable', class_implements($parent))) {
                $tryclasses[] = $parent;
            }   
        }
        foreach ($tryclasses as $classname) {
            $rendermethod = 'render_'.$classname;
            if (method_exists($this, $rendermethod)) {
                return $this->$rendermethod($widget);
            }
        }   
        // pass to the parent renderer if none suitable method was found here
        return $this->output->render($widget);
    }