[Refactor] Move notification creation to the Profile model

calsocial/models.py

@@ -326,14 +326,37 @@ class Profile(db.Model):  # pylint: disable=too-few-public-methods
 
         user_follow = UserFollow(follower=follower, followed=self, accepted_at=datetime.utcnow())
         db.session.add(user_follow)
-        notification = Notification(profile=self,
+        notification = self.notify(follower, self, NotificationAction.follow)
-                                    actor=follower,
+
-                                    item=self,
-                                    action=NotificationAction.follow)
         db.session.add(notification)
 
         return user_follow
 
+    def notify(self, actor, item, action):
+        """Notify this profile about ``action`` on ``item`` by ``actor``
+
+        :param actor: the actor who generated the notification
+        :type actor: Profile
+        :param item: the item ``action`` was performed on
+        :type item: any
+        :param action: the type of the action
+        :type action: NotificationAction, str
+        :raises TypeError: if ``actor`` is not a `Profile` object
+        :returns: the generated notification.  It is already added to the database session, but
+            not committed
+        :rtype: Notification
+        """
+
+        if not isinstance(actor, Profile):
+            raise TypeError('actor must be a Profile instance')
+
+        if isinstance(action, str):
+            action = NotificationAction[action]
+
+        notification = Notification(profile=self, actor=actor, item=item, action=action)
+
+        return notification
+
 
 class Event(db.Model):
     """Database model for events
@@ -426,10 +449,7 @@ class Event(db.Model):
         invite = Invitation(event=self, sender=inviter, invitee=invited)
         db.session.add(invite)
 
-        notification = Notification(profile=invited,
+        notification = invited.notify(inviter, self, NotificationAction.invite)
-                                    actor=inviter,
-                                    item=self,
-                                    action=NotificationAction.invite)
         db.session.add(notification)
 
         return invite