Re: Undo and Core Data issue

FROM : Michael Latta
DATE : Thu Mar 06 03:58:02 2008

The calls are on the Will/Did undo/redo notifications not the KVO 
callbacks on object changes.

I can account for the number of undo entries (the menu item disables 
at the right time), but would not mind pointers on how to detect what 
the undo changes.  I am not getting notifications from the managed 
object context for object changes, but that is probably me not doing 
something right.

What I am seeing is that my code changes a managed object property, I 
undo, and no change occurs in the managed object.  The property 
affected is a binary attribute (a CATransform3D as bytes).

I am looking at the object state before and after the undo using the 
Will/Did notifications for the undo manager.  Is it possible that 
either a) I am interfering with the undo manager because of the logic 
running in the notifications, or b) is it possible the changes are 
delayed to after the notifications?  The undo behaves the same as 
before I added any notification processing however.

Michael


On Mar 5, 2008, at 6:31 PM, Ben Trumbull wrote:

>> I call processPendingChanges from both the *Will* and *Did* 
>> notifications.

>
> Please stop.  It doesn't make sense for the context to coalesce 
> pending changes in the middle of the change to a single object 
> during the KVO callbacks.
>
> Your original problem description is a bit sparse.  Common problems 
> that produce that symptom are people doing things in a managed 
> object's initializer they shouldn't, people doing things in -
> awakeFromInsert/Fetch they shouldn't, or the undo stack having more 
> entries on it than they expect (i.e. undo works just fine, but the 
> stack isn't coalesced as the user expects)
> --
>
> -Ben