Core Data / NSTextView breaks only after save

Question

We have an NSTextView and some data saved about its contents in a core data Managed object context. Everything works great while the managed object context stays in memory. However when we save it, we get very weird fetch request behaviors.

For example, we run a fetch request that asks for all elements with a textLocation less than or equal to 15. The first object in the array we get back has a textLocation of 16.

I know I can't get a definitive answer here, as the code is fairly complex. But does anyone know what this issue smells of?

My thought is that we are somehow not getting the proper MOC synced with the NSTextView after saving? What could change that breaks this?

Thanks.

Answer 1

I finally managed to work out what was going on. I was setting textLocation using the setPrimitiveValue... just because I didn't want notifications to fire off. Turns out that's a really bad idea, because Core Data didn't know the value had changed. It still thought the value was 15 instead of 16.

Let this be a lesson: never bypass KVO unless you're INSIDE the managed object and you know what you're doing!