• 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: Getting information on updated n:m relationship
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Getting information on updated n:m relationship


  • Subject: Re: Getting information on updated n:m relationship
  • From: Mike Schrag <email@hidden>
  • Date: Sat, 10 Mar 2007 04:22:01 -0500

Can't hurt ...

On Mar 9, 2007, at 10:49 PM, Andrew Lindesay wrote:

Hello Mike;

You are dead right -- thanks very much for alerting me to this problem! I suppose If Apple were to implement a KVO-style notification "ObjectsWillChangeInStoreNotification" then it would be easy to implement a relatively safe change notification to take care of this problem. I can't immediately conceive of any other issues aside from ordering the changes.

Assuming you had one observer for each object store co-ordinator in the system or were only concerned with the default object store co- ordinator then you could cache the pending-update snaps from the "ObjectsWillChangeInStoreNotification" prior to the change and shift just the foreign keys over in the queued message.

I wonder if it is worth asking for this additional notification in a radar item? :-/

cheers.

What you describe here is the first implementation I made for Project Wonder, actually. It gets really nasty. The problem is that you have to also watch for updates, because if you change a to-one relationship, it only results in an update notification. But objectsChangedInStoreNotification doesn't provide enough information to respond correctly. By the time it gets to you, the snapshot cache is already updated, so you have no idea what the PREVIOUS value was (because that notification only gives you
...

___
Andrew Lindesay
www.lindesay.co.nz





_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden


References: 
 >Re: Getting information on updated n:m relationship (From: Andrew Lindesay <email@hidden>)
 >Re: Getting information on updated n:m relationship (From: Mike Schrag <email@hidden>)
 >Re: Getting information on updated n:m relationship (From: Andrew Lindesay <email@hidden>)

  • Prev by Date: Re: Getting information on updated n:m relationship
  • Next by Date: Re: WebObjects 5.3.3, DST and J2SE 1.4.2
  • Previous by thread: Re: Getting information on updated n:m relationship
  • Next by thread: Making a WO Project dependent on a WO Framework Project
  • Index(es):
    • Date
    • Thread