From: Dan Tapp <dhtapp@..._sig_line.com>
Date: 2004-07-07T05:57:37+09:00
Subject: Re: [RubyCocoa] Cocoa Bindings? (cont.)

Harry wrote:

> It's ugly, but a KVC-compliant object needs set<Key> methods. But this
> gave me the same error.
> 
> How to make Book KVC-compliant???
> 
> thx,
> Harry


Harry,

I'm kind of flying blind here, but from what I remember about Apple's 
KeyValueCoding protocol, it's only necessary to implement a couple of 
methods.  In more-or-less Obj-C form (I'm rusty), the first two are

- (id)valueForKey: aKey
- (void *)takeValue: someValue forKey: someKey

In other words, KVC is designed to circumvent setFoo/getFoo methods, not 
  to require them.

There is, IIRC, at least one other method needed for strict compliance, 
somthing to do with handling unbound (unrecognized) keys, but I can't 
remember the precise name or use.  I think on the Foundation Kit side, 
Apple may still include some default KVC behavior to relieve you from 
the need of implementing this.

Also, you might make sure that you're passing in first-class objects (as 
  Obj-C defines them, meaning non-scalars).  Earlier versions of 
Foundation Kit permitted a mixed approach, depending on the type of the 
ivar, but I do believe that later, Java-based versions standardized on 
wrapped primitives.

I hope at least some of that is useful, and wish I had Cocoa + Ruby to 
fiddle with these days :-)

- dan


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