Re: Bindings / Core Data: Ensuring a value is unique
Re: Bindings / Core Data: Ensuring a value is unique
- Subject: Re: Bindings / Core Data: Ensuring a value is unique
- From: Chris Blunt <email@hidden>
- Date: Thu, 14 Sep 2006 17:19:10 +0100
Sorry, shadow copy probably isn't the best description...long day
staring at code :) Basically, I have two NSArrayControllers that both
look at the same entity (is this a bad thing to do?). The reason
being whilst one arraycontroller *might* have a contentSet binding
(depending on the user's selection), the other must always return
every entity in the object graph:
Entity A --------------------------------
Entity B |
Entity C --- |
Entity D | |--- NSArrayController 2 (All)
Entity E |---NSArrayController 1 |
Entity F | |
Entity G --- |
Entity H --------------------------------
Here, all entities are returned by NSArrayController(2), but only
entities DEFG are returned by NSArrayController(1). I hope this makes
sense!
Anyway, the problem occurs when deleting one of the entities from
either of those NSArrayControllers. Although it vanishes from the
(current) controller, the entity remains in the other controller. It
also doesn't appear to be a valid entry, as if I edit the 'shadow'
entity in the other array controller, it is valid. I would take as
meaning it is not a 'nil' value?
Again, I'm not sure if having two controllers for the same data is
good practice, so please let me know if there is a better way to
tackle this problem!
Thanks,
Chris
--
www.chrisblunt.com
On 14 Sep 2006, at 16:52, I. Savant wrote:
You'll have to define "shadow copy".
I'm not sure if this is what you're seeing, but objects are not
immediately removed from the store when you delete them from a
context. Rather, they are marked as "deleted" and removed when the
store is saved. The Core Data Programming Guide explains this in
detail.
http://developer.apple.com/documentation/Cocoa/Conceptual/CoreData/
index.html
--
I.S.
On Sep 14, 2006, at 11:47 AM, Chris Blunt wrote:
I've got some strange behaviours appearing in my controllers now
as well - deleted records seem to leave a 'shadow' copy of the
record, despite multiple calls to [NSManagedObjectContext
processPendingChanges] and [NSArrayController prepareContent].
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden