Re: Undo and Core Data issue

FROM : Michael Latta
DATE : Thu Mar 06 06:26:53 2008

Here are the accessor methods I use for the property:


- (NSData*)transform {
   [self willAccessValueForKey:@"transform"];
   NSData *result = [self primitiveValueForKey:@"transform"];
   [self didAccessValueForKey:@"transform"];
   return result;
}

- (void)setTransform:(NSData*)value_ {
    [self willChangeValueForKey:@"transform"];
    [self setPrimitiveValue:value_ forKey:@"transform"];
    [self didChangeValueForKey:@"transform"];
}

These were generated by mogen.  I will try to see what is up with the 
managed object context notifications though.

The undo is by the user from the menu or keyboard.  I do create some 
undo groups to batch up related changes.  The undo group logic was 
lifted from an earlier application.  If I fail to close a group would 
that cause this?  Are there things to worry about when mixing calls to 
the undo manager and Core Data?

Michael



On Mar 5, 2008, at 7:53 PM, Ben Trumbull wrote:

> At 6:58 PM -0800 3/5/08, Michael Latta wrote:

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

>
> Ah, okay.  There shouldn't be any need to call -
> processPendingChanges there, unless you're programmatically working 
> with your own undo groups.
>

>> 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).

>
> Does your code changing the property trigger a KVO event (i.e. are 
> you missing a call to -willChangeValueForKey:) ?  Do you see 
> notifications from the MOC when you initially make the change ?
>
> Are you undoing programmatically or as a user ?
>

>> The undo behaves the same as before I added any notification 
>> processing however.

>
> That suggests the problem lies elsewhere.
> --
>
> -Ben