#Drupal Commerce Coupon - Limit one coupon per order rule
{ "rules_no_double_coupons" : {
"LABEL" : "No double coupons",
"PLUGIN" : "reaction rule",
"OWNER" : "rules",
"REQUIRES" : [ "rules", "commerce_coupon" ],
"ON" : { "commerce_coupon_applied_to_cart" : [] },
"IF" : [
{ "entity_has_field" : { "entity" : [ "commerce-order" ], "field" : "commerce_coupons" } },