Changes between Initial Version and Version 1 of Signals

Timestamp:

Jun 18, 2006, 3:10:00 PM (19 years ago)

Author:

Tyson Tate <tyson@…>

Comment:

Initial add. Needs some serious TLC.

Signals

@@ +1 @@
+== What Are Signals? ==
+
+Signals allow you to make Django call custom methods after common actions using a dispatcher. Beyond that, I really don't know much else. Please help expand this documentation, if you can.
+
+The author of Zyons [http://feh.holsman.net/articles/2006/06/13/django-signals talks about signals a bit here].
+
+== Example ==
+
+The following is taken from [http://zyons.com/ Zyons], the only place I've seen signals used so far. Unless I'm completely incorrect, the following code has the dispatcher call "increment_tag_summary" before a TagUserObject object is saved, and "decrement_tag_summary" after a TagUserObject object is deleted.
+
+=== models.py ===
+
+{{{
+from django.db.models import signals
+from django.dispatch import dispatcher
+
+[...]
+
+def increment_tag_summary(sender, instance, signal, *args, **kwargs):
+    [...]
+
+def decrement_tag_summary(sender, instance, signal, *args, **kwargs):
+    [...]
+
+dispatcher.connect( increment_tag_summary , signal=signals.pre_save, sender=TagUserObject )
+dispatcher.connect( decrement_tag_summary , signal=signals.post_delete, sender=TagUserObject )
+}}}