objc_getAssociatedObject example

gistfile1.m

#include <objc/runtime.h>

static char dynamicPropertyKey;

@interface TestClass (ParseObject)

@property (nonatomic) NSObject *dynamicProperty;

@end

@implementation TestClass (ParseObject)

- (NSObject *)dynamicProperty
{
    return objc_getAssociatedObject(self, &dynamicPropertyKey);
}

- (void)setDynamicProperty:(NSObject *)dynamicProperty
{
    objc_setAssociatedObject(self,
                             &dynamicPropertyKey,
                             dynamicProperty,
                             OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

@end