• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Forcing Core Data to save attribute changed behind its back?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Forcing Core Data to save attribute changed behind its back?


  • Subject: Re: Forcing Core Data to save attribute changed behind its back?
  • From: Kyle Sluder <email@hidden>
  • Date: Wed, 25 Jul 2012 17:04:50 -0700

On Wed, Jul 25, 2012, at 03:54 PM, Sean McBride wrote:
> On Tue, 24 Jul 2012 14:04:12 -0700, Quincey Morris said:
> >Another way of saying all this is that it may not be possible to
> >(reliably) inform Core Data that an attribute has changed without
> >changing the identity of the object that represents the value.
>
> :(  And changing the identity means using a different object... hmmmm...
> I guess since my object is basically a fancy wrapper of NSMutableData, I
> could actually copy my object but not copy the composed NSData too...

I was going to recommend something similar.

The inability to express mutation of a heavyweight model object is a
serious shortcoming in KVC/KVO. Most of the time it works; objects
generate the right change notifications and observers pick them up. But
then some intermediate observer gets smart and says "aha, the old and
new values are pointer-equal! I don't need to forward this change
notification for my derived keys!" and the entire thing breaks down.

I've filed bugs asking for richer self-description of key types
(basically -isOrderedToManyRelationshipKey: and the like). Perhaps we
should also have -isMutableObjectKey:. Either that or the framework
should stop eliding forwarded change notifications just because the
values don't compare pointer-equal.

--Kyle Sluder
_______________________________________________

Cocoa-dev mailing list (email@hidden)

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:

This email sent to email@hidden

References: 
 >Forcing Core Data to save attribute changed behind its back? (From: Sean McBride <email@hidden>)
 >Re: Forcing Core Data to save attribute changed behind its back? (From: Quincey Morris <email@hidden>)
 >Re: Forcing Core Data to save attribute changed behind its back? (From: Sean McBride <email@hidden>)

  • Prev by Date: Re: Forcing Core Data to save attribute changed behind its back?
  • Next by Date: spotlight importer extract file from zip archive
  • Previous by thread: Re: Forcing Core Data to save attribute changed behind its back?
  • Next by thread: Is it 'normal' that scrolling in a UIScrollView leaks some bytes?
  • Index(es):
    • Date
    • Thread