Support for order with multiple shipping adresses

[loicginoux]

Hi,
Our solidus app is going to need to ship to multiple adresses and I am evaluating the work to be done.
I see this PR #1138 that rolled back the shipment-adress association, because it was buggy... that's a shame :(
I guess I'll revert these changes in our app, start from here and fix the bugs mentionned in this PR.
I'll open a PR if I manage to get something working.
Not sure If I am the only one that needs shipment-adress association but that's seems more logical and more generic than having a order-adress association.
If you have any suggestions or advises that could help me make these changes, please let me know.
Thank you

[loicginoux]

One question: In the context of multiple shipment address, what's the use of order.ship_address ? Is it still necessary to have this address linked to the order if the association is only "valid" when the shipments ship to a unique address.

[loicginoux]

To respond to my last comment, I use the order.ship_address as a default address for a shipment, so by default a shipment has shipment_id: nil and so it refers to the order ship address.
Now I have another issue with this case :
1 - I set the order ship address, it creates all the shipments with default address
2 - I update one shipment address to be different from the order.ship_address,
3 - I update the order.ship_address.

Result: it will destroy and recreate all the shipments and therefore I loose the modified shipment address.

How could I keep a modified shipment address when updating the order ?

[AdnanTheExcellent]

@loicginoux try adding following functions in your order decorator:

  def ensure_updated_shipments; end
  
  def refresh_shipment_rates; end

This should override those order methods and prevent the shipments from being updated with new rates as well as prevent the shipments from being destroyed. Hope that helps. You will have to manually update your shipments though, which it seems like you want to do.