Use ShippableInterface in throughout the whole shipping cost calculation process

[dlhck]

Q	A
Bug report?	no
Feature request?	yes
BC Break report?	no
RFC?	yes

Currently some parts like the DefaultCarrierResolver and so on are using the ShippableInterface. Shipping rule conditions and actions are requiring the CartInterface. That means if the shippable object is no cart, the whole shipping cost calculation won't work.
So my suggestion would be to implement a function in the ShippableInterface called getSale and use the ShippableInterface throughout the whole process. If conditions or actions need some information like the store or currency of the sale, they just call getSale and get the cart or order or any other object that implements the SaleInterface

[dpfaffenbauer]

Well, not a 100 percent right... Shipping rule conditions and actions still require a Shippable, but the default implementations of some conditions/actions require that shipable is a cart, therefore you potentially could overwrite those.

But, you are definitely right that the current solution is not ideal

[dpfaffenbauer]

Think thats already done now