On Wed, Nov 14, 2007 at 08:55:09AM -0500, Marty Alchin wrote: > On Nov 14, 2007 12:21 AM, Malcolm Tredinnick <[EMAIL PROTECTED]> wrote: > > Jeremy's still got a valid problem, though, but I'm not sure > > reintroducing pre_save() and post_save() is a necessary step yet. > > Hopefully there's something else we can do. > > I wonder if there's a way to modify PyDispatcher (since we're > distributing our own copy anyway) so that it allows dispatching of a > particular signal to be suspended temporarily. That way, dispatched > signals might go into a queue, perhaps and get sent in order when the > signal is reactivated. Then, Jeremy's code might look something like > this: > > from django.dispatch import dispatcher > from django.db.models import signals > > class MyModel(Model): > def save(self): > queue = dispatcher.queue(signals.post_save) > super(MyModel, self).save() > > #extra work here > > queue.dispatch() > > def even_more(sender,instance): > #stuff that depends on extra work having already occurred > > dispatcher.connect(signals.post_save, even_more_stuff)
This is neat and all, but I don't think at actually solves the problem at hand.
If save is not overridden, when does queue.dispatch() get called?
The only way I can think of overcoming this is to dynamically modify self.save
when it is accessed (by overriding __getattr__). The signals are fired from
code that is dynamically appended to the save method. This guarrantees that the
signal is fired at the very end of the save call:
--------------------------------------------------------------------------------
class Model(object):
def save(self, ...):
...
def __getattr__(self, name):
value = super(Model, self).__getattr__(name)
if name == 'save':
def save(self, *args, **kwargs):
retval = value(self, *args, **kwargs)
send_postsave_signal()
return retval
return save
retun value
--------------------------------------------------------------------------------
This adds some overhead, of course, but it does do (roughly) what is being
asked.
-Forest
--
Forest Bond
http://www.alittletooquiet.net
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