Re: basic bindings question

FROM : Daniel Child
DATE : Thu May 15 06:43:39 2008

On May 15, 2008, at 12:09 AM, Ken Thomases wrote:

> Can you be more specific about why you want your controller to 
> observe its own number property?  What are you trying to 
> accomplish?  I suspect there's another way to accomplish what you're 
> interested in.

I'm simply trying to reduce bindings to the most basic case: type into 
a text field, have that value observed, and then reflect it somewhere 
else (as in another text field). The actual application I have in mind 
uses text fields to enable the user to specify sort fields, and rather 
than have a bunch of methods to check those values prior to sorting, I 
thought I could use bindings to automatically have those values set as 
soon as the user types them in. (I've used textDidChange in the past 
to accomplish something similar, but I thought this would be an easy 
case to try bindings. Especially since I might want to provide a more 
elegant interface for specifying sort fields prior to the sort.

>> In other words, your "myFoo addObserver: self <THE CONTROLLER> 
>> forKeyPath: @"number" becomes....
>>
>> - (void) awakeFromNib {
>>     [self addOberver: self forKeyPath: @"number" options: 0 context: 
>> NULL];

>
> There's a typo there.  You've missed the "s" in "addObserver".

Oops. Sorry about that, but I get a runtime error all the same:

[<NSApplication 0x119640> valueForUndefinedKey:]: this class is not 
key value coding-compliant for the key values.
2008-05-15 00:32:19.909 StringBinding[564:10b] *** Terminating app due 
to uncaught exception 'NSUnknownKeyException', reason: 
'[<NSApplication 0x119640> valueForUndefinedKey:]: this class is not 
key value coding-compliant for the key values.'

Thanks!