Michael Bayer wrote: > fine, but the name "get_local" is not so descriptive and also attracts > the focus away from the existing "identity_map" accessor. how about > we jack up the "identity_map" dictionary to be smarter ? so you could > say: > > session.identity_map.find(class_, ident, entity_name='foo') >
Are you going to make the identity_map a subclass of dict then? What about the weak_identity_map option--will there be a subclass of weakref.WeakValueDictionary too? That smells a bit. I guess the right way to do it is to make a wrapper around the "real" identity_map, but then you're starting to add more overhead to accessing the identity_map... Your suggestion is fine from a functional point of view, it just seems to add more complexity than it's worth (i.e. it would require an entire subclass (or two) or a wrapper instead of just a single function). The identity_map has always seemed like more of an implementation detail than an exposed part of the session interface (to me at least). The Session class is a facade to the UnitOfWork/identity_map. When I start to write code that depends heavily on those inner parts of the session I feel a bit nervous--like I'm writing fragile code. The other thing is documenting this in a way that people will be able to easily find it. The first place I would go to look for a feature like this is on the session--identity_map has always had the semantics of a plain dict. Would it be OK to name it session.find() and clearly document it's behavior with the other similar functions like session.get() and session.load()? The only possible issue is that it definitely does does NOT belong on Query unlike get() and load(). I expect it will be used more with expire() and expunge() so maybe that doesn't matter since neither of those methods are part of the query interface either. I don't really care, I'm just giving the first thoughts that come to mind here. ~ Daniel > > > On Mar 8, 10:07 am, "Daniel" <[EMAIL PROTECTED]> wrote: >> Could we add this new method on sqlalchemy.orm.Session? >> >> def get_local(self, class_, ident, entity_name=None): >> """Get an object from the identity map (do not hit the database) >> >> Returns None if the object does not exist in this session's >> identity map. >> """ >> idkey = self.mapper(class_, >> entity_name=entity_name).identity_key(ident) >> return self.identity_map.get(idkey) >> >> This is handy for doing tasks such as expiring/expunging/etc. an >> instance but only if it exists in the session. I'm not sure if it >> makes sense to have the entity_name parameter because I've never used >> it before, but I added it just in case. >> >> Thanks, >> ~ Daniel --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
