GFCoupons is the class which houses the main functionality of the Gravity Forms Coupons Add-on, it extends the _autolink_gffeedaddon class which is part of the add-on framework.
IntroductionThe GF_Field_Coupon class extends the GF_Field class, also known as the _autolink_field-object, it's responsible for determining how the Coupon field is rendered when the form is displayed and how it's value is handled during and after submission.
Coupons Feed Meta
IntroductionThe _autolink_feed-object meta for the Coupons add-on is an associative array containing the properties which determine the type of coupon and discount available.
This filter can be used to modify the coupon discount before it is applied to the form total.