Re: Correct use of NSViewController

FROM : Paul Szego
DATE : Thu Mar 20 23:27:30 2008

On 21/03/2008, at 12:35 AM, Jonathan Dann wrote:

>>

> Hi Cathy,
>
> Thanks again for your advice. I've got it working now and I'm almost 
> back I where I was before refactoring, I'm now running into a 
> bindings problem.
>
> Before using the view controllers I had put 2 tree controllers in my 
> window controller's nib, 2 outline views were then bound to these 
> and the tree controllers themselves got their content from an object 
> controller that was bound to the the keypath [(Window 
> Controller)File's Owner].document. So the object controller was a 
> proxy for my document and the tree controllers had shorter keypath 
> to traverse to get to the array they needed in my document subclass.
>
> Now when I do this I have the tree controllers and the document 
> proxy object controller in my view controller's nib. The only way I 
> can see to getting to the document is using the keypath



Have you considered using the representedObject property of the 
NSViewController?

To quote the API docs for NSViewController:

"...a generic representedObject property, to make it easy to establish 
bindings in the nib to an object that isn't yet known at nib-loading 
time or readily available to the code that's doing the nib loading."

In my code I create the view controller from the window controller, 
then set the representedObject. In my case it's usually the document, 
since I have the necessary controller objects in the document so that 
I can share selection status across various windows and views from 
different NIB's easily (remember that NSDocument is part of the 
*controller* layer in MVC, not the model).

HTH, Paul.