Question

I need to map a nested array with RestKit and I’ve almost got it (I think).

The JSON I need to map, looks like this

[
    {
        _id: "5058670183970a0002000450",
        app_store_url: "http://itunes.apple.com/app/culturonda-alto-adige-sudtirol/id534467629",
        comments: [
            {
                _id: "5058670783970a0002000456",
            },
            {
                _id: "50588d7f83970a000200065c",
            }
        ]
    }
]

My controllers to store the info looks like this:

#import <Foundation/Foundation.h>
#import "CommentData.h"

@interface DesignData : NSObject
    @property (retain, nonatomic) NSString *designId;
    @property (retain, nonatomic) NSSet *commentsRelationship;
@end

And:

#import <Foundation/Foundation.h>

@interface CommentData : NSObject
    @property (retain, nonatomic) NSString *commentId;
@end

My mapping looks like this:

RKObjectManager *objectManager = [RKObjectManager sharedManager];

RKObjectMapping *commentsMapping = [RKObjectMapping mappingForClass:[CommentData class]];
[commentsMapping mapKeyPathsToAttributes:@"_id", @"commentId", nil];

RKObjectMapping *designMapping = [RKObjectMapping mappingForClass:[DesignData class] ];
[designMapping mapKeyPathsToAttributes:@"_id", @"designId", nil];

[designMapping mapKeyPath:@"comments" toRelationship:@"commentsRelationship" withMapping:commentsMapping];

[objectManager.mappingProvider setMapping:designMapping forKeyPath:@""];

Comments gets into an array, but it doesn’t get stored in the comments controller. If I display the comments in the objecloader callback like this:

DesignData *designData = [objects objectAtIndex:0];
NSLog(@"Loaded %@ ", designData.commentsRelationship);

it gives me:

2012-10-20 22:37:55.258 RestKitTest5[4144:c07] Loaded {(
                                                        <CommentData: 0x8689730>,
                                                        <CommentData: 0x868bed0>,
                                                        <CommentData: 0x868bfe0>,
                                                        <CommentData: 0x868bf50>
                                                        )}

Which is a start. But I can’t do:

DesignData *designData = [objects objectAtIndex:0];
NSLog(@"Loaded %@ ", designData.commentsRelationship.commentId);

So how do I store the whole thing as an array?

Answer 1

I was already doing it right, I was just being stupid in the end.

I got the array and the objects in the array was of the right kind (CommentData), so all I had to do was to loop through the array and from there I could work with each object separately.