在我的购物车中包含运费报价的最佳方法是什么？
我网站的基本流程是
1.) User selects products
2.) User is shown cart
3.) repeat 1 and 2 until User wants to pay
4.) collect user details ( email, address where items will be shipped to )
5.) make payment via active merchant
6.) order is submitted to distributor.
我想插入一个运费信息，以便用户可以通过活跃的商家支付他的购买+运费。
1.) User selects products
2.) User is shown cart
3.) repeat 1 and 2 until User wants to pay
4.) collect user details ( email, address where items will be shipped to )
5.) calculate the cost of shipment, add cost to cart, show to user;
6.) make payment via active merchant
7.) order is submitted to distributor.
是否有宝石或插件可以帮助我，如果没有......我该如何完成？
谢谢
斯特凡