Adam, I had been using those very NSTreeController extensions in addition to my proxy classes. They use undocumented APIs (as far as I can tell), and broke when I updated my project to 10.5 only, because (I think) NSTreeController adopted a public API (NSTreeNode) in place of what the extensions were based on.
In principal, I'd be happy to share code that I think would be helpful, but my proxy classes are loaded with baggage I need to remove and I've had to table my private project in favor of the one that pays the bills. ;-) Doug K; On Mon, Mar 24, 2008 at 1:10 AM, Adam Gerson <[EMAIL PROTECTED]> wrote: > Hey Doug, > > Thanks so much for your help. Un checking "Raises For Not Applicable > Keys" did the trick. > > Take a look at DragAndDropOutlineEdit.zip > > http://homepage.mac.com/matthol2/cocoa/page2/page2.html > > The author has an NSTreeController extension that makes accessing the > "real" objects much easier. > > Would you be willing to share one of you proxy object classes as an > example? > > Adam > > > > My biggest gripe about outline views and tree controllers in 10.4 was > that > > it was difficult (impossible) to correlate items in the outline view > with > > their corresponding objects in the model in a (fully) supported way. > This > > is much better in 10.5; I haven't removed all the workarounds from my > code > > yet, but I am confident that I could and I will before I'm done. (I'm > > converting my app to 10.5-only, which simplifies things.) > > > > I have been using mixed entities in an outline view for a while, and I > > haven't found it to be a particular problem, even under 10.4. > > > > > > NSTreeController does want a specific entity type if it's using Entity > mode. > > It's certainly the case that entities in the tree need to implement the > > designated "children" and (optional) "Leaf" and "Count" keypaths, but > they > > can be different sub-entities of the designated entity type if its > feasible > > to go that route. > > > > If you bind an outline column to an property of the objects in the tree, > and > > some of your entities don't implement the property, you probably want to > > turn off the "Raises [exception] For Not Applicable Keys" flag on that > > binding. > > > > (As far as I know, I don't think the column bindings care if the > entities > > that it references a "fubar" property from are all from the same class, > or > > derive from a common class; it the entity implements "fubar", the > binding > > uses it.) > > > > In my case, I found it advantageous for a variety of different reasons > to > > put the tree controller in Class mode and create "proxy" objects (that > all > > derive from a base class that is the designated class for the tree > > controller). The benefits of doing this is that my proxy objects can > > implement any properties or behaviors that exist for the presentation in > the > > UI, independently of the Core Data entities that implement my model. > So, > > for example, my proxy objects implement a "displayName" property used in > my > > presentation, and derive those values in an entity-specific way without > > pushing that presentation implementation down into my model objects. > > > > The proxy approach is a little more work, but it's not all that bad if > you > > remember to "use the Force" (the wonderful-ness of key-value observing). > > > > I hope this helps; if I can clarify please let me know. > > > > Doug K; > > > > > > > > On Sun, Mar 23, 2008 at 7:55 PM, Adam Gerson <[EMAIL PROTECTED]> wrote: > > > > > > > > > > > > > > A general question: > > > > > > I have read a lot of discouraging posts on this list and out on the > > > blogs about the trio of NSTreeController, NSOutlIneView and CoreData. > > > Most of them come from the 10.4 era. Under 10.5 is this something that > > > is working better now? > > > > > > A specific question: > > > A lot of the NSTreeController, NSOutlIneView and CoreData example > > > projects use a single entity that can be both a child and a parent of > > > itself. 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? 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. > > > > > > Adam > > > _______________________________________________ > > > > > > 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/knowles.doug%40gmail.com > > > > > > This email sent to [EMAIL PROTECTED] > > > > > > > > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. 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