Rails 3.2.8 + RestKit - Mapping without KVC - ios

Question

So I am trying to grab information in JSON from my rails app with RestKit
My code to do so is like so:
App Delegate
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//Initialise RestKit
NSURL *URL = [NSURL URLWithString:#"https://myapp.dev"];
AFHTTPClient* client = [[AFHTTPClient alloc] initWithBaseURL:URL];
//Enable Activity Indicator Spinner
[AFNetworkActivityIndicatorManager sharedManager].enabled = YES;
[client setDefaultHeader:#"Accept" value:RKMIMETypeJSON];
RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
RKObjectMapping *eventMapping = [RKObjectMapping mappingForClass:[Info class]];
[infoMapping addAttributeMappingsFromDictionary:#{
#"sample":#"sample",
#"sample_1":#"sample_1"
}];
RKResponseDescriptor *infoDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:infoMapping
pathPattern:#"/info"
keyPath:nil
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptor:infoDescriptor];
}
View File
- (void)loadInfo
{
RKObjectManager *objectManager = [RKObjectManager sharedManager];
[objectManager getObjectsAtPath:#"/info"
parameters:nil
success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSArray *info = [mappingResult array];
NSLog(#"Loaded info: %#", info);
_info = info;
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error getting into"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
NSLog(#"Hit error: %#", error);
}];
}
The problem is. On the log output, RestKit tells me it maps everything successfully. But then when I attempt to view the object with both the method to log in the view file and with the debugger using po I get the following
374 Finished performing object mapping. Results: {
"<null>" = "<Info: 0xa291b30>";
}
I can't view the object and with breakpoints it shows up as:
I've been struggling with this for a few days and I'm not sure what else to try. Any help would be greatly appreciated

Answer 1

I ran into a similar problem. I'm not too sure why, but when I did the following it fixed it.
- (void)loadInfo
{
RKObjectManager *objectManager = [RKObjectManager sharedManager];
[objectManager getObjectsAtPath:#"/info"
parameters:nil
success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSArray *info = [mappingResult array];
NSLog(#"Loaded info: %#", info);
_info = info;
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error getting into"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
NSLog(#"Hit error: %#", error);
}];
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//Initialise RestKit
NSURL *URL = [NSURL URLWithString:#"https://myapp.dev"];
AFHTTPClient* client = [[AFHTTPClient alloc] initWithBaseURL:URL];
//Enable Activity Indicator Spinner
[AFNetworkActivityIndicatorManager sharedManager].enabled = YES;
[client setDefaultHeader:#"Accept" value:RKMIMETypeJSON];
RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
RKObjectMapping *eventMapping = [RKObjectMapping mappingForClass:[Info class]];
[infoMapping addAttributeMappingsFromDictionary:#{
#"sample":#"sample",
#"sample_1":#"sample_1"
}];
RKResponseDescriptor *infoDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:infoMapping
pathPattern:#"/info/:id"
keyPath:nil
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptor:infoDescriptor];
}

Answer 2

When you load an object representation that does not have a nesting keyPath, RestKit stores the mapped objects under the [NSNull null] key within the dictionary (since nil is not a valid dictionary key). You can retrieve the mapping results either by calling firstObject, array, or dictionary on the RKMappingResult object to access the mapped objects.
I see a follow-up question about mapping an array to a single object... what does your JSON look like and how are you trying to represent it?

Answer 3

RKResponseDescriptor *infoDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:infoMapping
pathPattern:nil
keyPath:nil
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];