--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/forums/signals.py	Sat May 05 17:10:48 2012 -0500
@@ -0,0 +1,114 @@
+"""
+Signal handlers & signals for the forums application.
+
+"""
+from django.db.models.signals import post_save
+from django.db.models.signals import post_delete
+import django.dispatch
+
+from forums.models import Forum, Topic, Post
+
+
+def on_topic_save(sender, **kwargs):
+    if kwargs['created']:
+        topic = kwargs['instance']
+        topic.forum.topic_count_update()
+        topic.forum.save()
+
+
+def on_topic_delete(sender, **kwargs):
+    topic = kwargs['instance']
+    topic.forum.topic_count_update()
+    topic.forum.save()
+    forums.latest.notify_topic_delete(topic)
+
+
+def on_post_save(sender, **kwargs):
+    if kwargs['created']:
+        post = kwargs['instance']
+
+        # update the topic
+        post.topic.post_count_update()
+        post.topic.save()
+
+        # update the forum
+        post.topic.forum.post_count_update()
+        post.topic.forum.save()
+
+
+def on_post_delete(sender, **kwargs):
+    post = kwargs['instance']
+
+    # update the topic
+    try:
+        post.topic.post_count_update()
+        post.topic.save()
+    except Topic.DoesNotExist:
+        pass
+    else:
+        # update the forum
+        try:
+            post.topic.forum.post_count_update()
+            post.topic.forum.save()
+        except Forum.DoesNotExist:
+            pass
+
+
+post_save.connect(on_topic_save, sender=Topic, dispatch_uid='forums.signals')
+post_delete.connect(on_topic_delete, sender=Topic, dispatch_uid='forums.signals')
+
+post_save.connect(on_post_save, sender=Post, dispatch_uid='forums.signals')
+post_delete.connect(on_post_delete, sender=Post, dispatch_uid='forums.signals')
+
+
+# Signals for the forums application.
+#
+# This signal is sent when a topic has had its textual content (title) changed.
+# The provided arguments are: 
+#   sender - the topic model instance 
+#   created - True if the topic is new, False if updated
+
+topic_content_update = django.dispatch.Signal(providing_args=['created'])
+
+# This signal is sent when a post has had its textual content (body) changed.
+# The provided arguments are: 
+#   sender - the post model instance 
+#   created - True if the post is new, False if updated
+
+post_content_update = django.dispatch.Signal(providing_args=['created'])
+
+
+def notify_new_topic(topic):
+    """
+    Sends the topic_content_update signal for a new topic instance.
+
+    """
+    topic_content_update.send_robust(topic, created=True)
+
+
+def notify_updated_topic(topic):
+    """
+    Sends the topic_content_update signal for an updated topic instance.
+
+    """
+    topic_content_update.send_robust(topic, created=False)
+
+
+def notify_new_post(post):
+    """
+    Sends the post_content_update signal for a new post instance.
+
+    """
+    post_content_update.send_robust(post, created=True)
+
+
+def notify_updated_post(post):
+    """
+    Sends the post_content_update signal for an updated post instance.
+
+    """
+    post_content_update.send_robust(post, created=False)
+
+
+# Avoid circular imports
+import forums.latest