Re: wiring up core data, bindings, NSArrayController and NSCollectionView
Re: wiring up core data, bindings, NSArrayController and NSCollectionView
- Subject: Re: wiring up core data, bindings, NSArrayController and NSCollectionView
- From: Philip Bridson <email@hidden>
- Date: Tue, 26 Feb 2008 19:23:17 +0000
Hi there, I am no expert on core data but I have been using it
extensively in my app over the past few months. From what I can see
from your code it looks similar to what I have been doing and it
works fine for me to be honest. What I think maybe the problem is
that just because you have bound the tables values to the array
controller does not mean you can just instantly add/remove things
from it. You need to connect (not bind) a button of some sorts to the
array controller which will give you the ability to add/remove/
select. To be honest I am not to sure about implementing drag and
drop in core data and I cannot find reference to it in the core data
documentation. I hope this helps, if it does not I am sorry.
Phil.
On 26 Feb 2008, at 19:09, Knud Hinnerk Möller wrote:
Hi,
I'm a little confused about a setup involving core data, bindings,
NSArrayControllers and an NSCollectionView. Things were fine before
I used core data:
- I have an NSCollectionView, where each view item represents a
KNBox, which contains a list of KNDesktopThings, represented by a
table
- I have subclassed NSCollectionView, so that each view item
receives its own NSArrayController, to which I bind the table
- I have also subclassed NSCollectionViewItem and made each item
the datasource of its table to implement drag and drop for the table
- before using core data, each view item would accept a drop,
create a new thing and add it to the array controller
- this worked perfectly
Now, with core data, things are a bit different:
- I have a data model with boxes and things. Things are related to
boxes via a "boxItems" relation
- here is how I set up the array controller (beware, this is
CocoaRuby):
arrayController.setEntityName("KNDesktopThing")
arrayController.setContent(box.boxItems)
- here is what I do when I accept a drop and want to create a new
thing:
managedObjectContext = NSApp.delegate.managedObjectContext
newThing =
NSEntityDescription.insertNewObjectForEntityForName_inManagedObjectCon
text("KNDesktopThing", managedObjectContext)
box.addBoxItemsObject(newThing)
arrayController.setContent(box.boxItems)
This works, but especially the last two lines make me wonder if I'm
not doing things the wrong way here. Is there a way I can set
things up so that I either:
- only add the new thing to the arrayController, which would
hopefully update the relation, or
- only add the new thing to the relation, which would hopefully
update the array controller.
Why do I want to use core data? Because I hope it will give me
"free" saving and undo.
Cheers,
Knud
-------------------------------------------------
Knud Möller, MA
+353 - 91 - 495086
Smile Group: http://smile.deri.ie
Digital Enterprise Research Institute
National University of Ireland, Galway
Institiúid Taighde na Fiontraíochta Digití
Ollscoil na hÉireann, Gaillimh
_______________________________________________
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:
40mac.com
This email sent to email@hidden
_______________________________________________
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