On Wed, May 6, 2009 at 6:36 PM, Melissa J. Turner <mjtur...@apple.com> wrote:
> Context is important. Also future-proofing. > > If your app was originally written against v1 CoreData (Tiger), you need to > update the app to be wise enough to check the store's metadata and run away, > run away from any store containing unexpected values (ie version hash > information). v1 CoreData always assumes that it can open a store it was > told to open until later evidence proves otherwise; later versions of > CoreData realized that was perhaps an unwise decision, and added the current > versioning and migration infrastructure. Due to binary compatibility issues, > applications compiled on Tiger will continue to exhibit the old behavior. > There's a general discussion of migration under 10.4 at > http://developer.apple.com/documentation/Cocoa/Conceptual/CoreData/Articles/cdZ104Versioning.html#//apple_ref/doc/uid/TP40002989 Thanks, but I think I should clarify things a bit more succinctly: 1 - Version 1 of the app and data model were *started* on Tiger (I created the project and worked on it under 10.4 for awhile). 2 - Later, when Leopard was released, I began linking against the 10.5 SDK and making use of some Leopard hotness. 3 - Version 1 of the app (and data model) was released as full-on 10.5-compiled and is 10.5-required (ie, has not been run on Tiger by any users). 4 - Version 2 of the app and data model have a working automatic migration for the very first change - the simple addition of a float attribute to a single entity. The problem is that version 1 of the app will open version 2 data files without complaint. This is unexpected and - I dare say - wrong. A question: Could my having created the project under Tiger, then later linking against 10.5 have caused this problem? In other words, is the 10.4 version of the xcdatamodel still 10.4-limited when compiled by momc, even when targeting 10.5? In any case, sorry for the previous wordy-confusion. That'll teach me to wax poetic in my posts. ;-) -- I.S. _______________________________________________ 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
