public function empty_cart()
{
$sid = mw()->user_manager->session_id();
$cart_table = $this->table;
\Cart::where('order_completed', 0)->where('session_id', $sid)->delete();
$this->no_cache = true;
$this->app->cache_manager->delete('cart');
$this->app->cache_manager->delete('cart_orders/global');
}