gistfile1.txt

- (id) serialize:(id) object{
    
    NSData *value = nil;
    id serializedObject = nil;
    
    if ([object isKindOfClass:[CKRecord class]]) {
        
        CKRecord *record = (CKRecord *)object;
        NSMutableDictionary *jsonDictionary = [[NSMutableDictionary alloc] init];
        
        NSDictionary *attributes = [record attributes];
        
        for (NSString *name in attributes) {
            
            // performSelector causes a warning, so using objc_msgSend instead
            id attrValue = objc_msgSend(record, NSSelectorFromString(name));
            
            if ([attrValue isKindOfClass:[NSString class]] || [attrValue isKindOfClass:[NSNumber class]]) {
                
                [jsonDictionary setValue:attrValue forKey:name];
                
            }
        }
        
        serializedObject = jsonDictionary;
    } else {
        
        serializedObject = object;
    }
    
    if([NSJSONSerialization isValidJSONObject:serializedObject]){
        
        NSError *error = nil;
        value = [NSJSONSerialization dataWithJSONObject:serializedObject options:0 error:&error];
        
        if(error)
            NSLog(@"%@", [error localizedFailureReason]);
    }
    
    return value;
}