contract/product_contract_variable_quantity/models/contract_line.py

# Copyright 2017 LasLabs Inc.
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).


from odoo import api, fields, models


class AccountAnalyticInvoiceLine(models.Model):
    _inherit = 'account.analytic.invoice.line'

    @api.onchange('product_id')
    def onchange_product(self):
        super(AccountAnalyticInvoiceLine, self).onchange_product()
        if self.product_id.is_contract:
            self.qty_type = self.product_id.qty_type
            self.qty_formula_id = self.product_id.qty_formula_id