contract/contract_invoice_start_end_dates/models/contract_line.py

# Copyright 2019-2020 Akretion France (http://www.akretion.com/)
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import models


class ContractLine(models.Model):
    _inherit = "contract.line"

    def _prepare_invoice_line(self):
        vals = super()._prepare_invoice_line()
        if self.product_id.must_have_dates:
            dates = self._get_period_to_invoice(
                self.last_date_invoiced, self.recurring_next_date
            )
            vals.update(
                {
                    "start_date": dates[0],
                    "end_date": dates[1],
                }
            )
        return vals