I am developing a site whose products will ship from the closest warehouse. I have already developed a module to find the nearest warehouse based on their ship to zip code. Does anyone know of a way to incorporate this into the UPS module so that the UPS module will call my 'warehouse' module first to replace the products ship from zip codes before getting its quote?
For example:
Normal Workflow
Customer checks out -> UPS gets quote
New Workflow
Customer check out-> UPS Module is called-> * Some sort of hook to call my module and replace product origin zip code with closest warehouse *->UPS Gets quote