[apostacy]

I'm trying to get an example from Hillegass' Cocoa Programming for Mac OS X book to run, and I keep getting an I'm NSInternalInconsistencyException , though I'm not sure why.

The purpose of the app is to show how Key-Value Coding can be binded (bound?) to an application.

Here's my code:

Code:
//
//  AppController.h
//

#import <Cocoa/Cocoa.h>

@interface AppController : NSObject {
	double fido;
}

- (id)init;
- (double)fido;
- (void)setFido:(double)x;

@end

//
//  AppController.m
//

#import "AppController.h"

@implementation AppController

- (id)init
{
	[super init];
	
	[self setValue:[NSNumber numberWithDouble:5]
			forKey:@"fido"];
	NSNumber* number = [self valueForKey:@"fido"]; 
	NSLog(@"fido: %@",number);
	return self; 
}

- (double)fido
{
	NSLog(@"-fido is returning %d", fido);
	return fido;
}

- (void)setFido:(double)x 
{
	NSLog(@"-setFido: is called with %d", x);
	fido = x;
}
@end

In Interface Builder, I'm simply dragging a vertical slider to the default .nib window, and checking "Continuous" "Bind to: AppController" (<- the name of OOP object I've created).

Fido was initially an int, but I changed it to a double because I was getting an exception:

Code:
2009-10-10 19:21:43.126 KVCFun[5084:10b] An uncaught exception was raised
2009-10-10 19:21:43.127 KVCFun[5084:10b] Cannot create double from object <AppController: 0x130700> of class AppController
2009-10-10 19:21:43.128 KVCFun[5084:10b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cannot create double from object

The problem is, whenever I run it, I get the follow exception thrown:

Code:
2009-10-10 19:22:38.403 KVCFun[5113:10b] Cannot create double from object <AppController: 0x130700> of class AppController
2009-10-10 19:22:38.404 KVCFun[5113:10b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cannot create double from object <AppController: 0x130700> of class AppController'

Any suggestions as to what could be wrong?

[Chuckit]

I think you want to bind to a particular property of the AppController rather than the AppController itself.

[apostacy]

Thanks Chuckit, and you sent me in the right direction. I needed to put the Object *and* the field name in the Inspector with focus on the slider. Thanks...

[apostacy]

Anyone know why I'm binding to "App Controller" or what "App Controller" is? The class I created in the above example happens to be called AppController, but it's obviously not referring to that (there's no space in my class name). It sounds like a reference to a Controller of the MVC model, but how does Interface Builder know what class I want to use as the Controller? (Didn't see any explanation anywhere online.)