DictionaryProperties

DictionaryProperties.h

//
//  DictionaryProperties.h
//
//  Created by KlausCPH on 3/1/13.
//  Source: http://stackoverflow.com/a/15167563/522498
//

@interface DictionaryProperties : NSObject{
    NSMutableDictionary* _backingDict;
}

@property (nonatomic, strong) NSMutableDictionary* backingDict;

+ (DictionaryProperties*) allocWithDictionary:(NSDictionary*)dict;

@end

DictionaryProperties.m

//
//  DictionaryProperties.m
//
//  Created by KlausCPH on 3/1/13.
//  Source: http://stackoverflow.com/a/15167563/522498
//

#import "DictionaryProperties.h"

@implementation DictionaryProperties

@synthesize backingDict = _backingDict;

- (id) initWithDictionary:(NSDictionary*)dict {
    if (self) {
        if ([dict isKindOfClass:[NSMutableDictionary class]]) {
            self.backingDict = (id)dict;
        } else {
            self.backingDict = [[NSMutableDictionary alloc] initWithDictionary:dict];
        }
    }
    return self;
}
+ (DictionaryProperties*) allocWithDictionary:(NSDictionary*)dict {
    return [[DictionaryProperties alloc] initWithDictionary:dict];
}


- (void)forwardInvocation:(NSInvocation *)invocation
{
    NSString* key = NSStringFromSelector(invocation.selector);
    invocation.selector = @selector(objectForKey:);
    [invocation setArgument:&key atIndex:2];
    
    if ([self.backingDict objectForKey:key]) {
        [invocation invokeWithTarget:self.backingDict];
    } else {
        [self doesNotRecognizeSelector:invocation.selector];
    }
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector{
    return [self.backingDict methodSignatureForSelector:@selector(objectForKey:)];
    
}
@end