RestKit: Problems mapping complex nesting, multiple levels needing forceCollectionMapping

Question

I'm trying to map some JSON data with RestKit, and have so far been unable to do it right. The data is a hierarchical set of days and registrations. It looks like the following (not a possibility for me to change it):

{
  "days": 
  {
    "2012-10-29": {
        "2106303": {
            "activityCode": "LU",
            "approved": false,
            "hours": 0.5,
            "description": "some description",
        },
        "2106304": {
            "activityCode": "VF",
            "approved": false,
            "hours": 7.5,
            "description": "some other description",
        }
        },
        "2012-10-30": null,
  }
}

My code looks like the following:

- (void)setupWeekMappingForManager:(RKObjectManager *)manager
{
    RKObjectMapping *registrationMapping = [RKObjectMapping mappingForClass:[Registration class]];
    registrationMapping.forceCollectionMapping = YES;
    [registrationMapping mapKeyOfNestedDictionaryToAttribute:@"registrationNumber"];

    RKObjectMapping *dayMapping = [RKObjectMapping mappingForClass:[Day class]];
    dayMapping.forceCollectionMapping = YES;
    [dayMapping mapKeyOfNestedDictionaryToAttribute:@"date"];

    // how can this relationship be mapped?
    [dayMapping mapKeyPath:@"(date)." toRelationship:@"registrations" withMapping:registrationMapping]; 

    [manager.mappingProvider setMapping:dayMapping forKeyPath:@"days"];
}

It happily returns the days, but I am unable to find a good way to map the relationship between the two types,

Any push in the right direction would be greatly appreciated,

Best Regards, Tommy

Answer 1

This worked for me:

- (void)setupWeekMappingForManager:(RKObjectManager *)manager
{
    RKObjectMapping *registrationMapping = [RKObjectMapping mappingForClass:[Registration class]];
    registrationMapping.forceCollectionMapping = YES;
    [registrationMapping mapKeyOfNestedDictionaryToAttribute:@"registrationNumber"];
    [registrationMapping mapKeyPath:@"(registrationNumber).description" toAttribute:@"description"];

    RKObjectMapping *dayMapping = [RKObjectMapping mappingForClass:[Day class]];
    dayMapping.forceCollectionMapping = YES;
    [dayMapping mapKeyOfNestedDictionaryToAttribute:@"date"];
    [dayMapping mapKeyPath:@"(date)" toRelationship:@"registrations" withMapping:registrationMapping];

    [manager.mappingProvider setMapping:dayMapping forKeyPath:@"days"];
}

This gives me a day object with a nice array of hour registrations as an NSArray. For reference, it looks like this:

@interface Day : NSObject
@property (nonatomic, readonly, copy) NSDate *date;
@property (nonatomic, readonly, strong) NSMutableArray *registrations;
@end