sale order to invoice line function

In purchase order, when transfrom order to invoice, there is a function call for each line, which permit to overload line creation.
In sale, there is no function for each, so if we want to add a field on order line, it's impossible to pass it to invoice line without inherit order function.
Can sale order to invoice function call order line new create_invoice_line function to permit to overload each line creation.