project_assignees/models/project_task.py

@@ -1,5 +1,5 @@
 
-from odoo import models, fields, _
+from odoo import models, fields, _, api
 
 
 class Task(models.Model):
@@ -7,3 +7,20 @@ class Task(models.Model):
 
     assignee_ids = fields.Many2many('res.users', 'assignee_ids_rel', string='Other Assignees')
 
+    @api.multi
+    def subscribe_assignees(self):
+        for task in self:
+            partner_ids = [a.partner_id.id for a in self.assignee_ids]
+            task.message_subscribe(partner_ids)
+
+    @api.multi
+    def write(self, vals):
+        result = super(Task, self).write(vals)
+        self.subscribe_assignees()
+        return result
+    
+    @api.model
+    def create(self, vals):
+        task = super(Task, self).create(vals)
+        task.subscribe_assignees()
+        return task