How to get JSON parsed object from RKObjectManager response block

Question

I'm sending a getObjectsAtPath request like below. Everything works fine but i'm trying to find a way the have the parsed json response available in the success block. As far as i know only response as string or data is available from the operation.HTTPRequestOperation or an array of mapped objects from the mappingResult.array.

Since i need post treatment based on values specific attributes in the JSON response i'm loins to get the parsed JSON response.

Any idea ? If this is not possible as is, how to parse the responseString using rest kit of AFNetwork parsing mechanism ?

Thanks

[self.objectManager getObjectsAtPath:@"api"
                              parameters:@{@"a11call": @"wallactivityById"}
                                 success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {

                                 } failure:^(RKObjectRequestOperation *operation, NSError *error) {

                                 }];