RosettaStoneKit is a magical Object Mapping framework. It converts dictionaries and arrays of data into instances of any classes. It can also convert your custom objects into dictionaries and arrays.

Motivation

There are other frameworks available that provide the same functionality, but they all made design decisions that limit their usefulness. This framework does not require that you subclass some special class that adds in all of the magic for you. It doesn't require a category on NSObject that pollutes every object with additional methods. And finally, the intent is to do one thing and do it very well. This framework doesn't include networking code or any other features.

Features

• Small public API surface
• Works with any subclass of NSObject
• Customizeable via custom PropertyTranslators
• Converts Objects to NSDictionarys
• Converts NSDictionary to Objects
• Works on NSArrays of NSDictionarys
• Well documented
• Well tested
• Support for Cocoapods/Carthage integration

Installation

Carthage

Add the following to your Cartfile:

github "Endoze/RosettaStoneKit" ~> 1.2

Then add the framework as a linked framework.

CocoaPods

Add the following to your Podfile:

pod 'RosettaStoneKit', '~> 1.2'

Then run pod install

Show me the code

// User.h

@interface User

@property (nonatomic, copy)   NSString *firstName;
@property (nonatomic, strong) NSNumber *userId;
@property (nonatomic, strong) NSDate *birthday;
@property (nonatomic, strong) NSString *lastName;

@end

// Elsewhere

#import <RosettaStoneKit/RosettaStoneKit.h>

NSDictionary *userDictionary = @{
  @"firstName": @"Joe",
  @"userId": 42,
  @"birthday": @"1970-01-01T00:00:00.000Z",
  @"lastName": @"User"
};

RosettaStone *stone = [RosettaStone sharedInstance];

User *joeUser = [stone translate:userDictionary toClass:[User class]];

When things aren’t so perfect

// Team.h

@interface Team

@property (nonatomic, copy)   NSString *name;
@property (nonatomic, strong) NSNumber *teamNumber;
@property (nonatomic, strong) NSArray *games;

@end

// Elsewhere

#import <RosettaStoneKit/RosettaStoneKit.h>

NSDictionary *teamDictionary = @{
  @"name": @"Piggers",
  @"number": 42,
  @"games": @[
    @{@"name": @"Table Hocky championships"},
    @{@"name": @"Ping Pong championships"}
  ]
};

RosettaStone *stone = [RosettaStone sharedInstance];

PropertyTranslator *numberTranslator = [propertyTranslatorForClass:[Team class]
                                                           fromKey:@"number"
                                                        toProperty:@"teamNumber"];
PropertyTranslator *gamesTranslator = [propertyTranslatorForClass:[Team class]
                                                     fromArrayKey:@"games"
                                                  toArrayProperty:@"games"
                                                        withClass:[Game class]];

[stone registerPropertyTranslator:numberTranslator];
[stone registerPropertyTranslator:gamesTranslator];

Team *piggers = [stone translate:teamDictionary toClass:[Team class]];

When you really need to change stuff

// Game.h

typedef enum : NSUInteger {
  PingPongGameType,
  FoosballGameType,
  TableHockeyGameType,
  NoGameType,
} GameType;

@interface Game

@property (nonatomic, copy) NSString *name;
@property (nonatomic) GameType type;

@end

// Elsewhere

#import <RosettaStoneKit/RosettaStoneKit.h>

NSDictionary *gameDictionary = @{
  @"name": @"FoosBall Championships",
  @"type": 2
};

RosettaStone *stone = [RosettaStone sharedInstance];
PropertyTranslator *gameTypeTranslator = [propertyTranslatorForClass:[Game class]
                                                             fromKey:@"type"
                                                           toProperty:@"type"
                                               withInterpolatorBlock:^id(id propertyValue) {
  NSUInteger number = [(NSNumber *)propertyValue unsignedIntegerValue];

  switch (number) {
    case 1:
      return PingPongGameType;
    case 2:
      return FoosballGameType;
    case 3:
      return TableHockeyGameType;
    default:
      return NoGameType;
  }
}];
[stone registerPropertyTranslator:gameTypeTranslator];

Game *foosballChampionshipGame = [stone translate:gameDictionary toClass:[Game class]];

Converting your objects into dictionaries

// User.h

@interface User

@property (nonatomic, copy)   NSString *firstName;
@property (nonatomic, strong) NSNumber *userId;
@property (nonatomic, strong) NSDate *birthday;
@property (nonatomic, strong) NSString *lastName;

@end

// Elsewhere

#import <RosettaStoneKit/RosettaStoneKit.h>

User *joeUser = [User new];
joeUser.firstName = @"Joe";
joeUser.userId = @2;
joeUser.lastName = @"User";

RosettaStone *stone = [RosettaStone sharedInstance];

NSDictionary *joeUserDictionary = [stone translateToDictionary:joeUser];