I'm left wondering "Under what circumstances would +[NSExpression expressionForFunction:selectorName:arguments:] be useful.
An example would be helpful, but I sure wasn't able to find one. Meanwhile, I switched to a simple bounds check, which works just fine. Thanks for your time. - Ron On Nov 27, 2009, at 5:54 PM, Jerry Krinock wrote: > > On 2009 Nov 27, at 12:23, Ron Aldrich wrote: > >> but I'd very much like to understand why this isn't working. >> >> On Nov 25, 2009, at 11:34 PM, Alexander Spohr wrote: >> >>> I am not sure if that works at all. I never fetched using methods that are >>> not part of the database as a qualifier. > > The reason hypothesized by Alexander is indeed the reason. Core Data fetch > predicates won't even work with ^transient^ properties. Your > -distanceFromLatitude is even less than transient -- it's derived. In my > experience, fetching with such a predicate will fail silently. > > These limitations are implied, actually somewhat understated, in the > following document which describes the "features" of the various store types: > > http://developer.apple.com/mac/library/documentation/cocoa/Conceptual/CoreData/Articles/cdPersistentStores.html#//apple_ref/doc/uid/TP40002875 > > If you read between the lines in the section "Fetch Predicates and Sort > Descriptors", you'll conclude that what you're doing is not going to work. > > Hey, be thankful that did you didn't test with the XML store and plan to > "flip the switch" to the sqlite store on shipping day. You would have been > very disappointed :)) > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/raldrich%40mac.com > > This email sent to raldr...@mac.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
