[IMP] Add constraint in configuration

pos_invoice_send_mail/models/pos_config.py

@@ -1,7 +1,8 @@
 # Copyright 2019 Druidoo - Iván Todorovich
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
 
-from odoo import models, fields
+from odoo import api, models, fields, _
+from odoo.exceptions import ValidationError
 
 
 class PosConfig(models.Model):
@@ -19,3 +20,9 @@ class PosConfig(models.Model):
         default=lambda self:
             self.env.ref('account.email_template_edi_invoice', False),
     )
+
+    @api.constrains('iface_invoice_mail', 'invoice_mail_template_id')
+    def _check_invoice_mail_templat_id(self):
+        for rec in self.filtered('iface_invoice_mail'):
+            if not rec.invoice_mail_template_id:
+                raise ValidationError(_('Invoice Email Template is required'))

pos_invoice_send_mail/models/pos_order.py

@@ -19,7 +19,6 @@ class PosOrder(models.Model):
         for order in self.browse(order_ids):
             if (
                 order.config_id.iface_invoice_mail
-                and order.config_id.invoice_mail_template_id
                 and order.invoice_id
                 and not order.invoice_id.sent
                 and order.pos_reference in refs_to_send_mail