Ian Bicking wrote:
> Phillip J. Eby wrote:
>> At 02:28 PM 6/25/2007 -0500, Ian Bicking wrote:
>>> Potentially a Zope-style minimal event
framework would work. Maybe
>>> something like:
>>>
>>> send_signal(signal_name, signal_data)
>>> subscribe(signal_name, listener)
>> That was what I was wondering, too, except I was
thinking it would be
>> sufficient to use entry points for subscription,
but only invoke the
>> entry points whose modules are in sys.modules. In
other words, never
>> actually import a module in order to invoke a
callback. That way,
>> subscription is a natural side effect of importing
the modules that
>> contain the listeners. Something like:
>>
>> def send_signal(group, name, *args, **kw):
>> for ep in iter_entry_points(group, name):
>> if ep.module_name in sys.modules:
>> ep.load()(*args, **kw)
>
> I don't think that makes sense for this case. The way
I imagine using
> it is:
>
> class MyApplication(object):
>
> def __init__(self, db):
> self.db = db
> subscribe('reload_resources', self.reload)
> def reload(self, data=None):
> self.db.close()
> self.db.open()
>
> That is, I subscribe one particular thing when it is
applicable, not
> because the library is on the system.
I forgot to add: this makes me think that some sort of
weakref handling
would be nice, because in this case I won't want the
application to
persist just because it's listening to this signal.
--
Ian Bicking | ianb colorstudy.com | http://blog.ianbicking.org
| Write code, do good | http://topp.openpla
ns.org/careers
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