将航运与Ruby on Rails集成
问题描述：
将运输报价包含在我的购物车中的最佳方法是什么？将航运与Ruby on Rails集成
我的网站的基本流程是
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.
我想插入一个发货信息，让用户可以付费通过积极的商人他的购买+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.
是否有一个宝石或插件来帮助我在这里，如果没有......我怎么能做到这一点？
谢谢
斯特凡