TL;DR
As of API version 2020-07, we are updating the allocation methods available for explicit discounts. Currently explicit discounts are assigned an allocation method ofone as they apply to one line. With this change the allocation methods will now includeeach andacross, withone being deprecated.
Context
Discounts currently have 3 types of allocation methods: across all lines (across), on each product (each), or on one line (one).
For example, imagine a checkout with two identical t-shirts, costing $10 each. Because they are the same product, they will be stored in a single line item, with a quantity of 2. Now, imagine we want to apply a $5 discount. This is how each value of allocation method would change the application of the discount:
- With across, the discount would be applied on the final value of the line item. Since we have two t-shirts, each costing $10, that would amount to $20. Applying the discount, we'd have $20 - $5 = $15, meaning the final total price would be $15.
- With each, the discount is applied on each product. In the example, we would first discount the product, meaning each product would cost $10 - $5 = $5 instead. Then, we would multiply that by the quantity, which is 2, giving us a final price of $10.
- Finally, we have
one.one is the exact same as across, except it also signals that the discount is an explicit discount - was applied on an explicit line only.
What does the change look like?
Currently, explicit discounts are always represented by allocation method one, and target_selection explicit.
To know whether a discount targets a single line, target_selection parameter should be used where a value of explicit would be expected; instead of the allocation_method parameter with a value of one.
For discounts applied on a single line (explicit), an allocation_method value across means that the discount had the intention of being applied across a line item. If the quantity of products on the line changes, the discount applied across the line will not change. While a value of each means that the discount had the intention of being applied on each product of the line. Thus, should the quantity of the line change, the total discount amount applied on that line should as well.
