cd_invoice.py

# -*- coding: utf-8 -*-
import logging
from datetime import datetime
from openerp import api, fields, models, tools

_logger = logging.getLogger(__name__)
LATE_LIMIT = 25


class AccountInvoice(models.Model):
    _inherit = 'account.invoice'
    is_late = fields.Boolean('Is Late', compute='compute_is_late')

    @api.multi
    @api.depends('date_invoice')
    def compute_is_late(self):
        """
        Computes if this bill is late. The bill is late if it has
        been the LATE_LIMIT days past the invoice date.
        """
        for invoice in self:
            _logger.info('DEPENDS_TEST: computing is late on invoice id ' + str(invoice.id))
            if invoice.date_invoice:
                date_invoice = datetime.strptime(invoice.date_invoice, tools.DEFAULT_SERVER_DATE_FORMAT)
                now = datetime.strptime(datetime.strftime(datetime.today(), tools.DEFAULT_SERVER_DATE_FORMAT), tools.DEFAULT_SERVER_DATE_FORMAT)
                invoice.is_late = (now - date_invoice).days > LATE_LIMIT