Avoid sending multiple notification emails to the same person when

he has commented multiple times.

svn path=/plone.app.discussion/trunk/; revision=46365

CHANGES.txt

@@ -4,6 +4,10 @@ Changelog
 1.0RC1 (unreleased)
 -------------------
 
+- Avoid sending multiple notification emails to the same person when
+  he has commented multiple times.
+  [maurits]
+
 - Disable discussion by default.
   [timo]
   

plone/app/discussion/comment.py

@@ -220,21 +220,30 @@ def notify_user(obj, event):
     conversation = aq_parent(obj)
     content_object = aq_parent(conversation)
 
+    # Avoid sending multiple notification emails to the same person
+    # when he has commented multiple times.
+    emails = set()
     for comment in conversation.getComments():
-        if obj != comment and \
-        comment.user_notification and comment.author_email:
+        if (obj != comment and
+            comment.user_notification and comment.author_email):
+            emails.add(comment.author_email)
+
+    if not emails:
+        return
+
     subject = translate(_(u"A comment has been posted."),
                         context=obj.REQUEST)
-            message = translate(Message(MAIL_NOTIFICATION_MESSAGE,
+    message = translate(Message(
+            MAIL_NOTIFICATION_MESSAGE,
             mapping={'title': content_object.title,
                      'link': content_object.absolute_url()}),
                         context=obj.REQUEST)
-        
+    for email in emails:
         # Send email
         if PLONE_4:
             try:
                 mail_host.send(message,
-                                   comment.author_email, 
+                               email,
                                sender,
                                subject,
                                charset='utf-8')
@@ -242,11 +251,11 @@ def notify_user(obj, event):
                 logger.error('SMTP exception while trying to send an ' +
                              'email from %s to %s',
                              sender,
-                                 comment.author_email)
+                             email)
         else:  # pragma: no cover
             try:
                 mail_host.secureSend(message,
-                                         comment.author_email,
+                                     email,
                                      sender,
                                      subject=subject,
                                      charset='utf-8')
@@ -254,7 +263,8 @@ def notify_user(obj, event):
                 logger.error('SMTP exception while trying to send an ' +
                              'email from %s to %s',
                              sender,
-                                 comment.author_email)
+                             email)
+
 
 def notify_moderator(obj, event):
     """Tell the moderator when a comment needs attention.

plone/app/discussion/tests/test_notifications.py

@@ -129,6 +129,40 @@ class TestUserNotificationUnit(PloneTestCase):
         
         self.assertEquals(len(self.mailhost.messages), 0)
 
+    def test_notify_only_once(self):
+        # When a user has added two comments in a conversation and has
+        # both times requested email notification, do not send him two
+        # emails when another comment has been added.
+
+        # Comment 1
+        comment = createObject('plone.Comment')
+        comment.text = 'Comment text'
+        comment.user_notification = True
+        comment.author_email = "john@plone.test"
+        self.conversation.addComment(comment)
+
+        # Comment 2
+        comment = createObject('plone.Comment')
+        comment.text = 'Comment text'
+        comment.user_notification = True
+        comment.author_email = "john@plone.test"
+        self.conversation.addComment(comment)
+        # Note that we might want to get rid of this message, as the
+        # new comment is added by the same user.
+        self.assertEquals(len(self.mailhost.messages), 1)
+        self.mailhost.reset()
+        self.assertEquals(len(self.mailhost.messages), 0)
+
+        # Comment 3
+        comment = createObject('plone.Comment')
+        comment.text = 'Comment text'
+        self.conversation.addComment(comment)
+        self.assertEquals(len(self.mailhost.messages), 1)
+        self.failUnless(self.mailhost.messages[0])
+        msg = str(self.mailhost.messages[0])
+        self.failUnless('To: john@plone.test' in msg)
+        self.failUnless('From: portal@plone.test' in msg)
+
 
 class TestModeratorNotificationUnit(PloneTestCase):