contract/contract_variable_quantity/models/contract_line_formula.py

# Copyright 2016 Tecnativa - Pedro M. Baeza
# Copyright 2018 Tecnativa - Carlos Dauden
# Copyright 2018 ACSONE SA/NV
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import _, api, fields, models, exceptions
from odoo.tools.safe_eval import safe_eval


class ContractLineFormula(models.Model):
    _name = 'contract.line.qty.formula'
    _description = 'Contract Line Formula'

    name = fields.Char(required=True, translate=True)
    code = fields.Text(required=True, default="result = 0")

    @api.constrains('code')
    def _check_code(self):
        eval_context = {
            'env': self.env,
            'context': self.env.context,
            'user': self.env.user,
            'line': self.env['contract.line'],
            'contract': self.env['contract.contract'],
            'invoice': self.env['account.invoice'],
            'quantity': 0,
            'period_first_date': False,
            'period_last_date': False,
            'invoice_date': False,
        }
        try:
            safe_eval(
                self.code.strip(), eval_context, mode="exec", nocopy=True
            )
        except Exception as e:
            raise exceptions.ValidationError(
                _('Error evaluating code.\nDetails: %s') % e
            )
        if 'result' not in eval_context:
            raise exceptions.ValidationError(_('No valid result returned.'))