Hello, I want to automatically calculate the subtotal with taxes in each line of sale.order.
I added a column "subtotal_with_taxes" and then I define this method (the two things in sale.order.line model):
@api.onchange('WHAT?')
def change_subtotal_with_taxes(self):
I want to execute this method every time when user presses "update" in the sale.order but I didn't see the way. How can I do this? I try with api.onchange('id') but not works, also I try api.onchange('price_subtotal') but not works because 'price_subtotal' is function field. 
