Question

I have some troubles mapping a JSON Array with RestKit.

This is the JSON File:

 "result": {"cities": [
                {"city": {"id": 2, "name": "Madrid"}, 
                 "cityImages": [{"image": {"url": "", 
                                           "image": "", 
                                           "blob": "", 
                                           "title":"Madrid"}
                                }]
                  }, 

                  {"city": {"id": 11001, "name": "Seville"}, 
                   "cityImages": [{"image": {"url": "", 
                                             "image": "", 
                                              "blob": "", 
                                              "title": "Seville Foto"}}, 
                                  {"image": {"url": "", 
                                             "image": "", 
                                             "blob": "", 
                                             "title": "Otra"}
                                   }]
                    }]
            }

Te problem is in the CityImage Array.
This is my class CityImage

@interface CityImage : NSObject 
@property (nonatomic, strong) NSString *imageURL;
@property (nonatomic, strong) NSString *image; 
@property (nonatomic, strong) NSString *imageBase64; 
@property (nonatomic, strong) NSString *title; 
@end

And this is the class City (that contains an Array of CityImages)

@interface City : NSObject
@property (nonatomic, strong) NSString *cityid;
@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSArray *cityImages;

And now, this is my mapping for cityImages:

RKObjectMapping* cityImageMapping = [RKObjectMapping mappingForClass:[CityImage class] ];
[cityImageMapping mapKeyPath:@"image.url" toAttribute:@"imageURL"];
[cityImageMapping mapKeyPath:@"image.image" toAttribute:@"image"];
[cityImageMapping mapKeyPath:@"image.blob" toAttribute:@"imageBase64"];
[objectManager.mappingProvider setMapping:cityImageMapping forKeyPath:@"result.cities.cityImages"];

And for cities:

RKObjectMapping *cityMapping = [RKObjectMapping mappingForClass:[City class]];
[cityMapping mapKeyPathsToAttributes:@"city.id", @"cityid", @"city.name", @"name", nil];
[cityMapping mapKeyPath:@"cityImages.image" toAttribute:@"cityImages"];
[objectManager.mappingProvider setMapping:cityMapping forKeyPath:@"result.cities"];

When the JSON is parsed it gives me this error:

W restkit.object_mapping:RKObjectMappingOperation.m:244 Failed transformation of value at keyPath 'image.url'. No strategy for transforming from '__NSArrayI' to 'NSString'
W restkit.object_mapping:RKObjectMappingOperation.m:244 Failed transformation of value at keyPath 'image.blob'. No strategy for transforming from '__NSArrayI' to 'NSString'
W restkit.object_mapping:RKObjectMappingOperation.m:244 Failed transformation of value at keyPath 'image.url'. No strategy for transforming from '__NSArrayI' to 'NSString'
W restkit.object_mapping:RKObjectMappingOperation.m:244 Failed transformation of value at keyPath 'image.blob'. No strategy for transforming from '__NSArrayI' to 'NSString'

I think I’ve forgot something, but although I have try almost everything I’ve found, the problem persist.
Any idea?.
Thank you for your help!!

Answer 1

Try setting this for the cityImageMapping: cityImageMapping.rootKeyPath = @"image" and map your attributes as url instead of image.url

Also, I believe you want the whole array of images instead of one image so map the cityImages array as follows:
[cityMapping mapKeyPath:@"cityImages" toAttribute:@"cityImages"];