On Sep 17, 2013, at 3:58 PM, Sean McBride wrote: > On Tue, 17 Sep 2013 15:52:05 -0600, Keary Suska said: > >> I appreciate the feedback--I am more looking for general feedback by >> fellow developers about either canonical forms or useful conventions in >> situations where using an ivar-backed attribute is determined to be >> useful, rather than to address a specific problem. > > An ivar-backed attribute in an NSManagedObject subclass? As opposed to an > attribute in the xcdatamodel itself? If so, I have found little use for > them, and generally prefer to use transient attributes, since they > participate in the "free" undo support. On occasion, I'll use an ivar to get > out of undo support actually.
I will say that these questions are specifically related to a software issue, though not about a specific CD issue, but rather software that needs to be able to identify certain possible approaches to coding problems that developers may encounter--just so everyone knows that this isn't just a mental exercise ;-) Anyway, I haven't had to but the docs do mention that for certain graphics-drawing-intensive applications that performance could be impacted by the constant conversions between scalars and objects, in which case a developer may choose to use an instance variable instead of the default storage (after having determined by scrupulous measurement that such conversions are the issue ;-) I hadn't considered the undo issue--I guess I just thought undo support was "automagical". If not, are you aware of whether it is implemented at the public or primitive accessor level? None of the doc examples I have seen do any undo handling... Keary Suska Esoteritech, Inc. "Demystifying technology for your home or business" _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
