Prospect modules (different approch than the OCA module partner_prospect in sale-workflow)

base_partner_prospect/partner.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# © 2015-2016 Akretion (Alexis de Lattre <alexis.delattre@akretion.com>)
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import models, fields, api, _
+from odoo.exceptions import ValidationError
+
+
+class ResPartner(models.Model):
+    _inherit = 'res.partner'
+
+    prospect = fields.Boolean(
+        string='Is a Prospect', track_visibility='onchange')
+
+    @api.onchange('customer')
+    def prospect_customer_change(self):
+        if self.customer and self.prospect:
+            self.prospect = False
+
+    @api.onchange('prospect')
+    def prospect_change(self):
+        if self.prospect and self.customer:
+            self.customer = False
+
+    @api.constrains('customer', 'prospect')
+    def partner_prospect_check(self):
+        for partner in self:
+            if partner.customer and partner.prospect:
+                raise ValidationError(_(
+                    "Partner '%s' cannot be both a prospect and a customer")
+                    % self.name_get()[0][1])