Re: Core Data - Need an Observer but where and how to implement
Re: Core Data - Need an Observer but where and how to implement
- Subject: Re: Core Data - Need an Observer but where and how to implement
- From: Jerry Krinock <email@hidden>
- Date: Tue, 2 Feb 2010 17:08:26 -0800
On 2010 Feb 02, at 11:54, Andreas Grauel wrote:
> I have two Entities - Person and Event - both are with
> a many to many relationship, because a person can have more events and a
> event can have more persons. After I have added a few Persons to an Event
> I'd like to display them on in a Table. But how? I tried a Binding with
> Events - selection - person.firstName but then always comes this Error.
>
> 2010-02-02 20:37:39.948 Kegeln[4128:a0f] [<_NSFaultingMutableSet
> 0x100227180> addObserver:forKeyPath:options:context:] is not supported. Key
> path: firstName
Classic problem. You can't bind through a to-many key path.
> I also have tried some other things but cannot figure it out. I have also
> tried to add an Observer but wasn't able to. I have tried to add an Observer
> to the EventArrayController, but didn't work or maybe i did it wrong. What
> can i do? Please help.
This looks like exactly the same question I asked about two and a half years ago. Probably 75% of what I said was wrong, but if you discount my profanities and concentrate on the responses from mmalc and others, you should get a proper start on this.
http://www.cocoabuilder.com/archive/cocoa/189290-managed-object-wants-per-relationship-attribute.html#189292
In particular, disregard my advice in the final Oct 03 message to use NSManagedObjectContextObjectsDidChangeNotification. I have since learned that NSManagedObjectContextObjectsDidChangeNotification fails to provide what is needed to make a real app which updates dependent properties, supports undo, etc.
_______________________________________________
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