Mapping nested objects and arrays - objective-c

Question

Good afternoon, everyone!
I'm trying to figure out how to map objects with nested arrays, but my project keeps being terminated due to an uncaught exception. I assume I'm not mapping something correctly, but I'm being told something isn't key-value coding compliant.
How do I map an object with a nested array?
Following is the footprint of the JSON I'm trying to map, the interface and implementation, and the error that's being throw, respectively. Finally, there is a link to my project on GitHub, incase I've left anything out, or seeing the full source would be helpful.
JSON
{
"href": "string",
"items": [
{
"type": "string",
"status": "string",
"name": "string",
"publisher": "string",
"publisherId": "string",
"description": "string",
"url": "string",
"smallLogoImageUrl": "string",
"tileImageUrl": "string",
"heroImageUrl": "string",
"tags": [
"string",
"string"
],
"createdOn": "2015-04-22T18:55:40.782Z",
"downloadUrl": "string",
"getProductCodeUrl": "string",
"metadata": {
"exeType": "string",
"packageFileName": "string",
"installDirectory": "string",
"executableName": "string"
},
"id": "string"
}
]
}
Interface (.h)
#interface SFrontPageItem : NSObject
#property (nonatomic, strong) NSString *type;
#property (nonatomic, strong) NSString *status;
#property (nonatomic, strong) NSString *name;
#property (nonatomic, strong) NSString *publisher;
#property (nonatomic, strong) NSString *publisherId;
#property (nonatomic, strong) NSString *productDescription;
#property (nonatomic, strong) NSString *url;
#property (nonatomic, strong) NSString *smallLogoImageUrl;
#property (nonatomic, strong) NSString *tileImageUrl;
#property (nonatomic, strong) NSString *heroImageUrl;
#property (nonatomic, strong) NSArray *tags;
#property (nonatomic, strong) NSString *createdOn;
#property (nonatomic, strong) NSString *downloadUrl;
#property (nonatomic, strong) NSString *getProductCodeUrl;
#property (nonatomic, strong) NSArray *metadata;
#property (nonatomic, strong) NSString *productID;
#end
#interface SFrontPage : NSObject
#property (nonatomic, strong) NSString *href;
#property (nonatomic, strong) NSArray *items;
#end
Implementation (.m)
- (void) getFrontPage
{
AppDelegate *appDelegate = [[NSApplication sharedApplication] delegate];
RKObjectMapping *itemMapping = [RKObjectMapping mappingForClass:[SFrontPageItem class]];
[itemMapping addAttributeMappingsFromDictionary:#{
#"type": #"type",
#"status": #"status",
#"name": #"name",
#"publisher": #"publisher",
//#"publisherId": #"publisherId",
#"description": #"description",
#"url": #"url",
//#"smallLogoImageUrl": #"smallLogoImageUrl",
#"tileImageUrl": #"tileImageUrl",
//#"heroImageUrl": #"heroImageUrl",
//#"tags": #"tags",
#"createdOn": #"createdOn",
//#"downloadUrl": #"downloadUrl",
//#"getProductCodeUrl": #"getProductCodeUrl",
//#"metadata": #"metadata",
#"id": #"productID"
}];
//itemMapping.forceCollectionMapping = YES;
RKObjectMapping *frontpageMapping = [RKObjectMapping mappingForClass:[SFrontPage class]];
[frontpageMapping addAttributeMappingsFromDictionary:#{
#"href": #"href"
}];
[frontpageMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:#"items"
toKeyPath:#"items"
withMapping:itemMapping]];
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:frontpageMapping
method:RKRequestMethodGET
pathPattern:nil
keyPath:nil
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[self.objectManager.HTTPClient setAuthorizationHeaderWithUsername:self.sconnection.apiKey.key password:self.sconnection.apiKey.secret];
[self.objectManager addResponseDescriptor:responseDescriptor];
[self.objectManager getObjectsAtPath:#"/api/frontpage/rest" parameters:nil
success:^(RKObjectRequestOperation *operation, RKMappingResult *result)
{
SFrontPage *newFrontpage = result.firstObject;
NSLog (#" HREF: %#", newFrontpage.href);
//NSLog (#"ITEMS: %#", newFrontpage.items.firstObject);
//SFrontPageItem *newFrontpageItem = newFrontpage.items.firstObject;
//NSLog (#"Unexpected Great Thing %#", newFrontpageItem );
[appDelegate.loginViewController apiConnectionSuccess];
} failure:^(RKObjectRequestOperation *operation, NSError *error)
{
[appDelegate.loginViewController updateLoginWindowHeaderLabelTo:#"Unable to Load Frontpage"];
[appDelegate.loginViewController apiConnectionFailure];
}];
}
Error
[<SFrontPageItem 0x6180001026d0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key description.
Source
The full source can be found on GitHub, with the relevant files being APIManager.h & APIManager.m.
I hope I've been clear enough, I sometimes miss the mark when forming a question about something I don't completely understand. I'm new to both ObjC, and RestKit, so I'm sure there are already a lot of confusing things in my code. Thanks for taking the time to read through it, and consider my question. If I can clarify anything, please let me know!
Michael

Answer 1

You map from description to description, but the property has the identifier productDescription. Change the mapping or the property name.

Answer 2

Try use some ready solutions.
https://github.com/aryaxt/OCMapper
https://github.com/isair/JSONHelper