function menu_induk($array, $parents = array(),$induk_menu = 0)
 {
    $lparents = array();
    if($induk_menu==0)
    {
        foreach ($array as $element) {
            if (($element['induk_menu'] != 0) && !in_array($element['induk_menu'],$parents)) {
                $parents[] = $element['induk_menu'];
            }
        }
    }
    return $parents;
 }


 function bootstrap_menu($array,$class1 = "dropdown",$induk_menu = 0)
    {
        $array_parents = menu_induk($array);
        $array_parents_link = menu_induk_link($array);
        $menu_html = '';
        foreach($array as $element)
        {
            if($element['induk_menu']==$induk_menu)
            {
                if(in_array($element['id_menu'],$array_parents))
                {
                    $menu_html .= '<li class="'.$class1.'">';
                    $menu_html .= '<a href="'.base_url().$element['link'].'" class="dropdown-toggle" data-toggle="'.$class1.'" role="button" aria-expanded="false">'.$element['nama_menu'].' <span class="caret"></span></a>';
                }
                else {
                    $menu_html .= '<li>';
                    $menu_html .= '<a href="' . $element['link'] . '">' . $element['nama_menu'] . '</a>';
                }
                if(in_array($element['id_menu'],$array_parents))
                {
                    $menu_html .= '<ul class="dropdown-menu" role="menu">';
                    $menu_html .= bootstrap_menu($array, "dropdown-submenu" , $element['id_menu'], $array_parents);
                    $menu_html .= '</ul>';
                }
                $menu_html .= '</li>';
            }

        }
        return $menu_html;
    }

CREATE TABLE `menu` (
  `id_menu` int(10) NOT NULL,
  `nama_menu` varchar(40) DEFAULT NULL,
  `link` varchar(50) NOT NULL,
  `induk_menu` int(5) DEFAULT NULL,
  `is_root` tinyint(1) DEFAULT NULL,
  `aktif` tinyint(1) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;