"Phillip J. Eby" <pje@telecommunity.com>

At 01:58 PM 6/15/00 +1000, Stuart 'Zen' Bishop wrote:

...

Its not a problem with ZScheduler, it a problem that no one has written a plug-in logging system that is good enough for what you are trying to do. The existing zLOG API is fine (well - it could be better), but just needs someone to write the relevant modules. Hmm... I think I'll add a section to the Interfaces Wiki...

Hm... this could work well with Observer->Observable, too. Imagine firing ObservableEvents, and subscribing a "Log" object to them...

Ayup, logging is one of the classic instances of that pattern. The problem with using Observer for logging, especially in a fine-grained way, is that the dependency arrows point the "wrong way" -- the logger object needs to register as an Observer of many Subjects, but has no good way to find them all. The typical solution is to add an intermediate observer to all the containers, who watches the add and remove operations, and then either notifies the logger of new subscriptions it should perform, or performs them on behalf of the logger. Tres. -- =========================================================== Tres Seaver tseaver@digicool.com Digital Creations "Zope Dealers" http://www.zope.org