On Jul 29, 2010, at 5:59 PM, Martin Stanley wrote: >> Even if you could capture a proposed deletion before save, which AFAIK you >> can't, you will still have an undo mess. IMHO you best bet is to capture the >> situation at the point of editing the predicate, substituting the deleted >> item with a placeholder like "<deleted>". > I agree, trying to capture the deletion would be an unholy mess. > > But perhaps I haven't explained the problem clearly enough. The problem > arises not when the predicate is being edited, but when entity referenced in > the predicate is deleted. I need to find a way to notice this and then to > take corrective action. > > Also, it would be nice to let the user know that the deletion of this entity > will invalidate a SmartGroup. Once the model is changed appropriately I can > perform this check in response to the user request to delete the entity.
I was assuming that your language use was loose, but do you *really* mean deleting an entity, or simply deleting a managed object of that entity type? The former would be a horribly bad idea in most cases. Assuming that you don't mean the above, I still don't think you are articulating the problem correctly. Deleting isn't the problem--Core data does that just fine. It seems that it is some *consequence* of the deletion that is the problem. What is that precisely? That a "smart group" will be invalid? Unless you present it otherwise to the user, it is just a predicate, and it is just as valid if it doesn't match anything. But then if the problem is that you don't want this condition to occur without user consent--which may be a friendly feature--as long as project objects can't be deleted by core data internal processes (such as the result of a delete rule), you have complete control over the deletion, so you can check it then, before it even occurs. 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
