Omnipay itemBag price should be converted to payment currency

[joostwaaijer]

Description

Fixes bug when trying purchase items in a secondary currency, in stead of the primary currency

Related issues

#22

[boboldehampsink]

@lukeholder any chance of merging this?

[boboldehampsink]

@nfourtythree maybe?

[nfourtythree]

Hi @boboldehampsink & @joostwaaijer

We will take a review of this to see if this is something we can merge. Commerce only supports paying in a different currency and for that method, we only convert the payment amount (usually the order total). Converting each line item's price could potentially introduce totalling errors where conversion rate would mean that the sum of their totals might not add up to the order total.

Will update this PR when we have further info.

Thanks!

[boboldehampsink]

@nfourtythree thanks. I see what you mean but right now it is also buggy, see #22

[nfourtythree]

Certainly, @boboldehampsink, as I mentioned we will review and see what the best course of action is here.

#22 does relate to the, now deprecated, PayPal gateway plugin. The superseded PayPal gateway plugin does deal with this, albeit in a rudimentary way by not sending the breakdown. Unfortunately, this is a limitation at the moment, as mentioned, due to the way Commerce deals with paying in a different currency to the base currency.

We will update you when we have more information, thanks!

[boboldehampsink]

@nfourtythree any information yet?

[nfourtythree]

Hi All

We have spent a good amount of time looking into and discussing this. The limitation still stands that because Commerce only ever converts the payment amount/order total to the payment currency we can't integrate this PR. This is due to the reasons already stated that there is a chance that converting all the line item prices might end up in a situation where the items do not total up correctly. This could cause problems with gateways and that is something we need to avoid.

In future versions of the gateways we are also looking at the fact that if the payment is in a different currency to the base currency, it is a partial payment or you are paying an outstanding balance that is part of the order total we may have to dynamically turn of the "send cart info". This will be a decision that is made on a per gateway scenario depending on what their individual platforms/APIs accept/expect.

For now, your best bet here is to use the Gateway::EVENT_AFTER_CREATE_ITEM_BAG event, this gives you the opportunity to overwrite the item bag with whatever data you see fit, so if you would like to convert the currency you can do. This would be then be left up to you to make sure to meet the gateway's requirements.

Hope this explanation and guide to a solution helps, thanks!