# -*- coding: utf-8 -*- from openerp import models, fields, api class AccountVoucher(models.Model): _inherit = 'account.voucher' comision = fields.Float( string='Comisión', compute='_compute_comision', store=True ) @api.model def _get_porcentaje(self): param = self.env['ir.config_parameter'].get_param( 'voucher_comision.porcentaje', '2' ) return float(param) @api.depends('amount') def _compute_comision(self): porcentaje = self._get_porcentaje() for rec in self: rec.comision = rec.amount * porcentaje / 100 if rec.amount else 0