A simple Objective-C wrapper that allows easier use of Associated Objects.

NSObject+AssociatedValues.h

//
//  NSObject+AssociatedValues.h
//
//  Created by Shilo White on 11/8/11.
//  Copyright (c) 2011 Shilocity Productions. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

@interface NSObject (AssociatedValues)
- (void)setAssociatedValue:(id)value forKey:(NSString *)key;
- (void)setAssociatedValue:(id)value forKey:(NSString *)key policy:(objc_AssociationPolicy)policy;
- (id)associatedValueForKey:(NSString *)key;
- (void)removeAssociatedValueForKey:(NSString *)key;
- (void)removeAllAssociatedValues;
@end

@implementation NSObject (AssociatedValues)
- (void)setAssociatedValue:(id)value forKey:(NSString *)key {
    [self setAssociatedValue:value forKey:key policy:OBJC_ASSOCIATION_ASSIGN];
}

- (void)setAssociatedValue:(id)value forKey:(NSString *)key policy:(objc_AssociationPolicy)policy {
    objc_setAssociatedObject(self, key, value, policy);
}

- (id)associatedValueForKey:(NSString *)key {
    return objc_getAssociatedObject(self, key);
}

- (void)removeAssociatedValueForKey:(NSString *)key {
    objc_setAssociatedObject(self, key, nil, OBJC_ASSOCIATION_ASSIGN);
}

- (void)removeAllAssociatedValues {
    objc_removeAssociatedObjects(self);
}
@end