[ADD] mass_mailing_event_sms: allow to perform SMS marketing on attendees

PURPOSE

Do like Mail Attendees, but with SMS, in a single "Contact" button.

SPECIFICATIONS

Specifications:
  * on event form view, rename "Mail Attendees" button to "Contact Attendees"
    and open a mixed for view on mailing.mailing allowing to choose the type
    of mailing;
  * send SMS to all attendees;
  * see https://drive.google.com/file/d/1-7iDaNJSZbdTW1PYMU2vWtfPHGJmN7SF/edit

FP "Testing Weekend nothing works" request

LINKS

Task ID 2074848 (sms on attendees)
PR #37185

addons/mass_mailing_event/views/event_views.xml

@@ -6,7 +6,7 @@
         <field name="inherit_id" ref="event.view_event_form"/>
         <field name="arch" type="xml">
             <xpath expr="//button[@name='button_cancel']" position="after">
-                <button name="action_mass_mailing_attendees" string="Mail Attendees" type="object" attrs="{'invisible': [('seats_expected', '=', 0)]}"/>
+                <button name="action_mass_mailing_attendees" string="Contact Attendees" type="object" attrs="{'invisible': [('seats_expected', '=', 0)]}"/>
             </xpath>
         </field>
     </record>

addons/mass_mailing_event_sms/__init__.py

@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from . import models

addons/mass_mailing_event_sms/__manifest__.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+{
+    'name': 'Event Attendees SMS Marketing',
+    'category': 'Hidden',
+    'version': '1.0',
+    'description':
+        """
+SMS Marketing on event attendees
+================================
+
+Bridge module adding UX requirements to ease SMS marketing o, event attendees.
+        """,
+    'depends': [
+        'event',
+        'mass_mailing',
+        'mass_mailing_sms',
+        'sms',
+    ],
+    'data': [
+    ],
+    'auto_install': True,
+}

addons/mass_mailing_event_sms/models/__init__.py

@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from . import event

addons/mass_mailing_event_sms/models/event.py

@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import models
+
+
+class Event(models.Model):
+    _inherit = "event.event"
+
+    def action_mass_mailing_attendees(self):
+        # Minimal override: set form view being the one mixing sms and mail (not prioritized one)
+        action = super(Event, self).action_mass_mailing_attendees()
+        action['view_id'] = self.env.ref('mass_mailing_sms.mailing_mailing_view_form_mixed').id
+        return action