Thanks Chris, I am going to look into creating a category. Its not something I have ever done, but now I have some bedtime reading for tonight.
http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC/Articles/chapter_4_section_1.html Would you suggest a category that extends an NSManagedObject? Adam On Sun, Mar 23, 2008 at 10:08 PM, Chris Hanson <[EMAIL PROTECTED]> wrote: > On Mar 23, 2008, at 4:55 PM, Adam Gerson wrote: > > A specific question: > > It is always good to ask specific questions. "Is ____ still broken in > 10.5?" is not a very specific question, especially since there may be > a number of developers who are using it quite successfully in Mac OS X > 10.4. > > > > If I want to model parent and child entities that have a > > completely different set of attributes (one is a group of objects, the > > other is the objects themselves) am I better of not using > > NSTreeController and CoreData? > > NSTreeController and Core Data are entirely orthogonal here -- > specifically, Core Data has nothing at all to do with your question. > Your question would be the same regardless of whether Core Data is > involved. > > > > One problem I have already run into is > > that when you bind your entire OutlineView column to a > > NSTreeController entity it wants the parents and children to all have > > the same attributes. > > > NSTreeController expects every column of an NSOutlineView it is > controlling to have the same attributes, and it expects every object > at every level of the hierarchy it displays to use the same keys for > both the children of a node and for whether a node is a leaf. That's > just how NSTreeController is designed. > > One way you can interoperate with this in your own code is to *not* > bind directly to modeled attributes and relationships, but instead > bind to keys that you define in categories in your own code. For > example, let's say you're showing a filesystem hierarchy. You have > two classes of item, File and Folder, where File instances are leaf > nodes and Folder instances can have contents. You could add - > isLeafForTreeController and -childrenForTreeController methods to each > class, to return the appropriate values. > > You may also be able to work with NSTreeNode objects directly -- which > are used to represent the contents of an NSTreeController in 10.5 -- > but unfortunately how to do so is still very sparsely documented. > (It's not clear to me whether you can just set the content of a tree > controller to a collection of NSTreeNode instances, for example.) > > -- Chris > > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
