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+keyPathsForValuesAffectingValueForKey: vs +keyPathsForValuesAffecting<Key>.
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// | |
// main.m | |
// KVO | |
// | |
// Created by Damien DeVille on 10/26/13. | |
// Copyright (c) 2013 Damien DeVille. All rights reserved. | |
// | |
#import <Foundation/Foundation.h> | |
@interface Animal : NSObject | |
- (NSString *)identity; | |
@property (copy, nonatomic) NSString *name; | |
@end | |
@implementation Animal | |
- (NSString *)identity | |
{ | |
return [NSString stringWithFormat:@"My name is %@.", [self name]]; | |
} | |
+ (NSSet *)keyPathsForValuesAffectingValueForKey:(NSString *)key | |
{ | |
NSMutableSet *keyPaths = [NSMutableSet setWithSet:[super keyPathsForValuesAffectingValueForKey:key]]; | |
if ([key isEqualToString:@"identity"]) { | |
[keyPaths addObject:@"name"]; | |
} | |
return keyPaths; | |
} | |
@end | |
#pragma mark - | |
@interface Monkey : Animal | |
@property (assign, nonatomic) NSUInteger age; | |
@end | |
@implementation Monkey | |
- (NSString *)identity | |
{ | |
return [[super identity] stringByAppendingFormat:@" I am %lu.", [self age]]; | |
} | |
+ (NSSet *)keyPathsForValuesAffectingValueForKey:(NSString *)key | |
{ | |
NSMutableSet *keyPaths = [NSMutableSet setWithSet:[super keyPathsForValuesAffectingValueForKey:key]]; | |
if ([key isEqualToString:@"identity"]) { | |
[keyPaths addObject:@"age"]; | |
} | |
return keyPaths; | |
} | |
@end | |
#pragma mark - | |
@interface Animal (Funky) | |
@property (readonly, copy, nonatomic) NSString *funkyName; | |
@end | |
@implementation Animal (Funky) | |
- (NSString *)funkyName | |
{ | |
NSString *name = [self name]; | |
if (name == nil) { | |
return nil; | |
} | |
return [@"Funky " stringByAppendingString:name]; | |
} | |
+ (NSSet *)keyPathsForValuesAffectingFunkyName | |
{ | |
return [NSSet setWithObjects:@"name", nil]; | |
} | |
@end | |
#pragma mark - | |
@interface Observer : NSObject | |
@end | |
@implementation Observer | |
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context | |
{ | |
// nop | |
} | |
@end | |
#pragma mark - | |
int main(int argc, const char **argv) | |
{ | |
Monkey *monkey = [[Monkey alloc] init]; | |
Observer *observer = [[Observer alloc] init]; | |
[monkey addObserver:observer forKeyPath:@"identity" options:(NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew) context:NULL]; | |
[monkey addObserver:observer forKeyPath:@"funkyName" options:(NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew) context:NULL]; | |
[monkey setName:@"Bryan"]; | |
[monkey setAge:12]; | |
return 0; | |
} |
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