cooperative-market/beesdoo_purchase/models/purchase.py

# -*- coding: utf-8 -*-
from openerp import models, api

class PurchaseOrder(models.Model):
    _inherit = 'purchase.order'

    @api.model
    def create(self, vals):
        purchase_order = super(PurchaseOrder, self).create(vals)
        command_contact = self.env.ref('beesdoo_base.commande_beescoop', raise_if_not_found=False)
        # We do not need to update sale_order.mail_followers_ids, the link is automatic ?!
        if command_contact:
            self.env['mail.followers'].create({'res_model' : 'purchase.order', 'res_id' : purchase_order.id, 'partner_id' : command_contact.id}) 
        return purchase_order