On Aug 16, 2011, at 13:14 , Andrew Kinnie wrote: > Hmm. Well the generated code was created by Xcode 4's "Create > NSManagedObject Subclass" based on the model. The properties are created > along with the methods, however due to an earlier issue, I changed @dynamic > to @synthesize for the various properties in the .m for Article and > MediaResource. There are no ivars. Apparently this caused the problem. > Changing it back to @dynamic fixed it. > > Further debugging indicated that when I deleted an article, using > > [self.moc deleteObject:myArticle]; > > and at the point that is called, the article had a media object in it's media > relationship (doing po myArticle in the debugger indicates this) but when I > click continue, it lands on a breakpoint in the removeMediaObject method in > Article, and the value passed in exists, but the media relationship itself > contains no objects. That is where the crash occurred. So apparently, Core > Data was doing the cascade delete, then because I had "@synthesize" instead > of "@dynamic" it called the class's removeMediaObject method trying to remove > the object that is no longer in the relationship, thus it breaks by calling > removeObject" on the __NSSet0 singleton object.
If you change a Core Data model property from @dynamic to @synthesize, then it isn't using Core Data any more -- it's using ivars for the property backing store instead. That means you end up with 2 properties with the same name -- the model-derived property that Core Data knows about, and the subclass-derived property that the rest of your app knows about. No wonder that crashes start to occur. You *cannot* swap @synthesize and @dynamic for a Core Data property, not ever. You can replace the Core Data implementation (the @dynamic one, so to speak) with your own implementation. Just not the @synthesize'd one. Not ever. _______________________________________________ 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
