Add button to activity form

golem_mail_activity_registration/models/golem_activity.py

@@ -24,6 +24,11 @@ class GolemActivity(models.Model):
     """ GOLEM Activity adaptations """
     _inherit = 'golem.activity'
 
+    @api.multi
+    def activity_members_mass_mailing(self):
+        return self.get_mass_mailing_action('members')
+
+
     @api.multi
     def get_mass_mailing_action(self, action_type):
         """ Call activity mass mailing presend wizard """

golem_mail_activity_registration/views/golem_mail_activity_views.xml

@@ -18,6 +18,21 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 -->
 <odoo>
   <data>
+    <!-- golem activity form adaptations -->
+    <record id="golem_activity_form_inherit_golem_mail_activity_registration"
+      model="ir.ui.view">
+      <field name="name">Golem Activity form adaptations golem mail activity registration</field>
+      <field name="model">golem.activity</field>
+      <field name="inherit_id" ref="golem_activity.golem_activity_form"/>
+      <field name="arch" type="xml">
+        <sheet position="before">
+          <header>
+            <button name="activity_members_mass_mailing" string="Activity members mass mailing"
+              type="object" class="oe_highlight"/>
+          </header>
+        </sheet>
+      </field>
+    </record>
     <!-- Activity members mass mailing action-->
     <record id="action_activity_members_mass_mailing" model="ir.actions.server">
       <field name="name">Activity members mass mailing</field>