Commerce Coupon by product reference

Important notice: This module is only compatible with the 1.x branch of Commerce coupon.

This module lets you specify certain products that must be present in an order before a particular coupon can be redeemed. For percentage coupons, the percent discount is only applied to the referenced products. If the referenced items are removed from the order, then the coupon is also removed.

It uses a multi-value entity reference field attached to the coupon. If the field is left empty then the coupon will be valid for all products.

The module adds:

1. A new condition for evaluating whether an order contains a product referenced by a coupon (commerce_couponprodref_order_has_referenced_product);
2. A multi-value entity reference field linking coupons to products (field_commerce_couponprodref);
3. A Rules component for applying percentage coupons to line items where they match the reference field (rules_commerce_couponprodref_apply_coupon_to_line_item_component);
4. A new coupon validation rule that won't allow a coupon to be redeemed if it has a populated reference field that doesn't match any of the products in the cart (rules_commerce_couponprodref_validate_refererenced_products);
5. A new rule that revalidates coupons after a product is removed from the cart, removing any with references that aren't satisfied by the new cart (rules_commerce_couponprodref_remove_invalid_coupons).

The future!

I understand that with Commerce Coupon 2.x and Commerce Discount this module won't be needed any more. Presumably it won't be needed for Drupal 8/Commerce 2.x either.

Installation & Use

Enable the module as normal and it should work without configuration. Edit a
coupon to see the product reference field.