Realm+JSON

A concise Mantle-like way of working with Realm and JSON.

Installation

Add the following to your CocoaPods Podfile

pod 'Realm+JSON', '~> 0.1'

or clone as a git submodule,

or just copy files in the Realm+JSON folder into your project.

Using Realm+JSON

Simply declare your model as normal:

typedef NS_ENUM(NSInteger, MCEpisodeType) {
    MCEpisodeTypeFree = 0,
    MCEpisodeTypePaid
};

@interface MCEpisode : RLMObject

@property NSInteger episodeID;
@property NSInteger episodeNumber;
@property MCEpisodeType episodeType;

@property NSString *title;
@property NSString *subtitle;
@property NSString *thumbnailURL;

@property NSDate *publishedDate;

@end

RLM_ARRAY_TYPE(MCEpisode)

Then pass the result of NSJSONSerialization or AFNetworking as follows:

  [MCEpisode createInRealm:[RLMRealm defaultRealm] withJSONArray:array];

or

  [MCEpisode createInRealm:[RLMRealm defaultRealm] withJSONDictionary:dictionary];

When you specify a primaryKey (see below), objects in the realm with same primary key value will be replaced instead of a duplicate version of the object added.

Configuration

You should specify the inbound and outbound JSON mapping on your RLMObject subclass like this:

+ (NSDictionary *)JSONInboundMappingDictionary {
  return @{
         @"episode.title": @"title",
         @"episode.description": @"subtitle",
         @"episode.id": @"episodeID",
         @"episode.episode_number": @"episodeNumber",
         @"episode.episode_type": @"episodeType",
         @"episode.thumbnail_url": @"thumbnailURL",
         @"episode.published_at": @"publishedDate",
  };
}

+ (NSDictionary *)JSONOutboundMappingDictionary {
  return @{
         @"title": @"title",
         @"subtitle": @"episode.description",
         @"episodeID": @"id",
         @"episodeNumber": @"episode.number",
         @"publishedDate": @"published_at",
  };
}

Leaving out either one of the above will result in a mapping that assumes camelCase for your properties which map to snake_case for the JSON equivalents.

Specify the primary key property like this:

+ (NSString *)primaryKey {
  return @"episodeID";
}

As you can do with Mantle, you can specify NSValueTransformers for your properties:

+ (NSValueTransformer *)episodeTypeJSONTransformer {
  return [MCJSONValueTransformer valueTransformerWithMappingDictionary:@{
              @"free": @(MCEpisodeTypeFree),
              @"paid": @(MCEpisodeTypePaid)
      }];
}

License

Realm+JSON is under the MIT license.