RestKit - Relashionship Mapping with CoreData - Response Error - objective-c

Question

I have a Guest entity and inside guest is a City entity. I've setup a relashionship in CoreData and RestKit using the RKRelationshipMapping.
I've mapped a single entity correctly, but when I use RKRelationshipMapping to add a City Entity it seems to generate a this error while calling the following method with the #"cityId" property:
-[RKPropertyInspector classForPropertyNamed:ofEntity:]: unrecognized selector sent to instance
My mapping code:
RKObjectManager *objectManager = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:self.serverBaseAddress]];
objectManager.managedObjectStore = [RKManagedObjectStore defaultStore];
[RKObjectManager setSharedManager:objectManager];
RKEntityMapping *cityEMapping = [RKEntityMapping mappingForEntityForName:self.cityEntityName inManagedObjectStore:[RKManagedObjectStore defaultStore]];
[cityEMapping addAttributeMappingsFromDictionary:#{
#"id" : #"cityId",
#"name" : #"name"
}];
RKEntityMapping *guestEMapping = [RKEntityMapping mappingForEntityForName:self.entityName inManagedObjectStore:[RKManagedObjectStore defaultStore]];
[guestEMapping addAttributeMappingsFromDictionary:#{
#"name" : #"name",
#"photo" : #"photo",
#"comment" : #"comment",
#"id" : #"guestId",
#"date" : #"date"
}];
[guestEMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:#"city"
toKeyPath:#"city"
withMapping:cityEMapping]];
guestEMapping.identificationAttributes = #[ #"guestId" ];
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:guestEMapping method:RKRequestMethodAny pathPattern:self.postGetAddress keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptor:responseDescriptor];
And where the app stops: (propertyClass receiving 0x00 in propertyClass = [[RKPropertyInspector sharedInspector]...)
- (Class)classForKeyPath:(NSString *)keyPath
{
NSArray *components = [keyPath componentsSeparatedByString:#"."];
Class propertyClass = self.objectClass;
for (NSString *property in components) {
propertyClass = [[RKPropertyInspector sharedInspector] classForPropertyNamed:property ofClass:propertyClass isPrimitive:nil];
if (! propertyClass) propertyClass = [[RKPropertyInspector sharedInspector] classForPropertyNamed:property ofEntity:self.entity];
if (! propertyClass) break;
}
return propertyClass;
}
And here is the json:
[{"id":"3","name":"Convidado3","city":{"id":"2","name":"São Paulo"},"date":"Data2","comment":"comentario3","photo":":P"},
{"id":"2","name":"Convidado2","city":{"id":"1","name":"Rio de Janeiro"},"date":"Data2","comment":"comentario2","photo":":|"},
{"id":"1","name":"Convidado1","city":{"id":"1","name":"Rio de Janeiro"},"date":"Data1","comment":"comentario1","photo":":)"},
{"id":"5","name":"Convidado5","city":{"id":"4","name":"Vitória"},"date":"Data4","comment":"comentario5","photo":":K"},
{"id":"4","name":"Convidado4","city":{"id":"3","name":"Belo Horizonte"},"date":"Data3","comment":"comentario4","photo":";)"}]
The entity Guest has a relationship called city which is connected to the City Entity through a relationship called guests in the following manner:
Guest.....City
city<--->>guests
If I simply remove the relationship it works ok, without city sub object...
Any help or suggestions appreciated...

Answer 1

I've solved the problem:
After going through all the steps in debug, I changed the following line
From:
RKEntityMapping *cityEMapping = [RKEntityMapping mappingForEntityForName:self.cityEntityName inManagedObjectStore:[RKManagedObjectStore defaultStore]];
To:
RKEntityMapping *cityEMapping = [RKEntityMapping mappingForEntityForName:#"City" inManagedObjectStore:[RKManagedObjectStore defaultStore]];
And it worked!
I don't understand the problem, as I checked the value of self.cityEntityName during debug and it is #"City", so technically it should work. As for the line:
RKEntityMapping *guestEMapping = [RKEntityMapping mappingForEntityForName:self.entityName inManagedObjectStore:[RKManagedObjectStore defaultStore]];
works just fine... without any changes, I don't know what to say. Thanks for the suggestions.