Recursive Function

if ( ! function_exists('recursive_list')) {
    function recursive_list($data) {
        $str = '';
        foreach ($data as $list) {
            $str .= "<li";
            $str .= (count($list['child']) > 0 ? ' class="dropdown-submenu"' : '');
            $str .= ">";
            $str .= anchor(site_url('home/readmore/'.$list['id'].'/'.$list['slug']), $list['post_title']);
            $subchild = recursive_list($list['child']);
            if ($subchild != '') {
                $str .= "<ul class='dropdown-menu' role='menu'>".$subchild."</ul>";
            }
            $str .= "</li>";
        }
        return $str;
    }
}