reporting-engine/report_substitute/wizards/mail_compose_message.py

# Copyright 2019 ACSONE SA/NV
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import api, models


class MailComposeMessage(models.TransientModel):

    _inherit = 'mail.compose.message'

    @api.multi
    @api.onchange('template_id')
    def onchange_template_id_wrapper(self):
        if self.template_id:
            report_template = self.template_id.report_template
            if (
                report_template
                and report_template.action_report_substitution_rule_ids
                and self.env.context.get('active_ids')
            ):
                active_ids = self.env.context.get('active_ids')
                old_report_template = report_template
                self.template_id.report_template = (
                    old_report_template.get_substitution_report(active_ids)
                )
                onchange_result_with_substituted_report = (
                    super().onchange_template_id_wrapper()
                )
                self.template_id.report_template = old_report_template
                return onchange_result_with_substituted_report
        return super().onchange_template_id_wrapper()