NSTreeController problems

FROM : Charles Srstka
DATE : Sun May 18 21:57:33 2008

Lately, I've been trying to update my stodgy old ways and try to 
incorporate some of the new technologies Cocoa has picked up over the 
years when starting new projects (my main app has had to be compatible 
with older OS X versions, so I haven't had much opportunity to jump 
into the world of bindings prior to now). One of these is 
NSTreeController. Unfortunately, I'm having a bit of trouble using 
figuring out how to do what I want with it.

1. The order of the objects in my (non-Core Data) data model is 
sometimes important, so rather than using the tree controller to add 
objects, I have been adding them manually by calling the appropriate -
insertObject:in<key>atIndex: methods. Okay, that works pretty well, 
and the objects show up in the NSOutlineView. However, I'd like to 
select the objects after I insert them. Now, I know where these 
objects are in the model, but since the order of the objects in the 
outline view might be different due to the user clicking on one column 
header or another to sort, and since the index paths sent to the tree 
controller's -setSelectedIndexPaths: method seem to be based on the 
interface, not the model, I don't know exactly where these objects are 
in order to select them. NSTreeController appears to have no -
indexPathForObject: method or anything similar - does anyone know a 
way around this?

   1a. At first I thought that since I am making a sibling to the 
currently selected object, I could just get the parent's index path 
via [[treeController selectionIndexPath] 
indexPathByRemovingLastIndex], then get the node at that index path 
and iterate through its -childNodes until I find the one whose -
representedObject is the correct model object, but there doesn't seem 
to be any way to get NSTreeController to give the node (or the model 
object, for that matter) for an index path. Does anyone else find this 
a little bizarre?

2. Okay, so I've got my objects displaying in an NSOutlineView, and 
now I'd like to add a search feature. Rather than eliminating the 
options that don't match, what I want to do is find the object, expand 
all its ancestors in the outline view so it's visible, and select it. 
Finding the model object is easy, and doing the rest *would* be easy 
enough if I weren't using NSTreeController - just climb the family 
tree, use -rowForItem: for each, expand it, and then use -rowForItem: 
to get the object and select it. Of course, with NSTreeController we 
have all these NSTreeNode objects instead of the actual objects 
themselves in the outline view, so -rowForItem: won't work. Is there 
any way to find the rows for the various nodes in the family tree of 
an object without resorting to just iterating through every row in the 
outline view? Any way to get the tree node for a given model object?

For me, the jury's still out - are these new bindings features really 
that useful, or is the best route just to pretend it's 2002 and 
continue to do things via the simpler method of making an outline 
delegate?

Any assistance you can give is greatly appreciated.

Charles