[SOLVED] Restkit map the response to a parent Entity - when response does not have parent entity values

I'm using RestKit 0.2 version in my project. I have a situation where I need to map the response to an already saved it's parent entity.

My Parent Class is Conversation & conversation can have many messages.

First I'm saving the all the conversations in Coredata under Conversation entity.

Then I called this url for get all the messages related to a specific conversations.

http://myUrl/conversations/bdc34e2a-fa1f-4dbe-83b4-3296ff657e93/messages

bdc34e2a-fa1f-4dbe-83b4-3296ff657e93 is my conversation id

Here is my json response.

[  
 {  
  "id":"5f67f6f5-934d-403e-ac64-19dbd4defeda",
  "sent_at":"2016-06-08T12:24:28+0000",
  "read_at":null,
  "sender":{  },
  "content":"test message",
  "attachment":{  }
 },
 {  
  "id":"c4d18b33-4c54-4e7e-a964-a5cedc087122",
  "sent_at":"2016-06-08T09:59:41+0000",
  "read_at":null,
  "sender":{  },
  "content":"abc test message",
  "attachment":{  }
 },

My Json response does not have the conversation property, but I need to map all my messages under the relevant conversation.

RKEntityMapping *messageMapping = [RKEntityMapping mappingForEntityForName:[Message entityName] inManagedObjectStore:[[DataStoreManager sharedManager] managedObjectStore]];

[messageMapping addAttributeMappingsFromDictionary:@{
                                                     @"id":@"identifier",
                                                     @"sent_at": @"date",
                                                     @"content": @"message",

                                                    }];

messageMapping.identificationAttributes = @[@"identifier"];

I have many to one relationship for messages to conversation.

[messageMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:nil toKeyPath:@"conversation" withMapping:**conversationMapping**]];

But how can I create conversationMapping ?

Edited - Trying with routing & meta data

As @Wain suggested , I'm trying to use restkit routing

// conversation mapping
RKEntityMapping *conversationMapping = [RKEntityMapping mappingForEntityForName:[Conversation entityName] inManagedObjectStore:[[BADataStoreManager sharedManager] managedObjectStore]];

[conversationMapping addAttributeMappingsFromDictionary:@{
                                                          @"@metadata.routing.parameters.identifier": @"identifier"

                                                          }];


conversationMapping.identificationAttributes = @[@"identifier"];

[messageMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:nil toKeyPath:@"messages" withMapping:conversationMapping]];

here is my response descriptor

RKResponseDescriptor *conversationDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:[EntityMappingProvider messagesResponseMapping] method:RKRequestMethodAny pathPattern:@"/conversations/:identifier/messages" keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];

[[DataStoreManager sharedManager].router.routeSet addRoute:[RKRoute routeWithName:@"conversations" pathPattern:@"/conversations/:identifier/messages" method:RKRequestMethodGET]];

[[DataStoreManager sharedManager] addResponseDescriptor:conversationDescriptor];

[[DataStoreManager sharedManager] getObjectsAtPathForRouteNamed:@"conversations" object:conversation parameters:nil
                                                         success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
                                                             RKLogInfo(@"response %@",mappingResult);
                                                         }

                                                         failure:^(RKObjectRequestOperation *operation, NSError *error) {
                                                             RKLogInfo(@"error response %@", error.localizedDescription );
                                                         }];

object:conversation will be sent when user select one conversation from the conversation list.

But still conversation are not correctly mapped to the messages.

& I can call this method only once, then I'm getting the following error .

reason: 'Cannot add a route with the same name as an existing route.'

but it should be usable to all the conversations , whenever user selects a conversation this method will be called.

Solution

I have used response descriptors to map conversations & users before mapping messages in the conversations. So when I used the response descriptor for the messages in the conversations, it was mapped to previously defined descriptors.

So I had to use pathPattern & specify the response descriptors , then it mapped correctly , as @Wain explained , I have initialized all the response descriptors once & use getObjectsAtPathForRouteNamed several times.

Finally here is my conversation mapping & it's response descriptor

// conversation mapping
RKEntityMapping *conversationMapping = [RKEntityMapping mappingForEntityForName:[Conversation entityName] inManagedObjectStore:[[BADataStoreManager sharedManager] managedObjectStore]];
[conversationMapping addAttributeMappingsFromDictionary:@{
                                                          @"@metadata.routing.parameters.identifier": @"identifier"

                                                          }];
conversationMapping.identificationAttributes = @[@"identifier"];
[messageMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:nil toKeyPath:@"messages" withMapping:conversationMapping]];

// Response descriptor 
RKResponseDescriptor *conversationDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:[EntityMappingProvider messagesResponseMapping] method:RKRequestMethodAny pathPattern:@"/conversations/:identifier/messages" keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[[DataStoreManager sharedManager].router.routeSet addRoute:[RKRoute routeWithName:@"conversations" pathPattern:@"/conversations/:identifier/messages" method:RKRequestMethodGET]];
[[DataStoreManager sharedManager] addResponseDescriptor:conversationDescriptor];
[[DataStoreManager sharedManager] getObjectsAtPathForRouteNamed:@"conversations" object:conversation parameters:nil
                                                         success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
                                                             RKLogInfo(@"response %@",mappingResult);
                                                         }
                                                              failure:^(RKObjectRequestOperation *operation, NSError *error) {
                                                             RKLogInfo(@"error response %@", error.localizedDescription );
                                                         }];