Hello,
The trigger is the HikaShop one regarding the order object :
www.hikashop.com/support/documentation/6...l#onAfterOrderUpdate
But when a vendor subsale is modified, you have the "order_type" which is equal to "subsale" instead of "sale" for customer order.
Thus, you can check for the "subsale" ; get the "order_parent_id" and load the customer order if you need ; and notify the customer regarding the modification of a part of its order.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.