@interface FPFuelPurchaseLog : NSObject
@property (nonatomic, readonly) NSDate *logDate;
@property (nonatomic, readonly) NSDecimalNumber *odometerReading;
@property (nonatomic, readonly) NSDecimalNumber *numGallonsPurchased;
@end

@interface FPFuelStation : NSObject
@property (nonatomic, readonly) NSString *fuelStationName;
@property (nonatomic, readonly) NSDecimalNumber *pricePerGallon;
@property (nonatomic, readonly) NSArray *fpLogs;

- (void)addFpLog:(FPFuelPurchaseLog *)fpLog;
@end

@interface FPFuelPurchaseLogSerializer : HCHalJsonSerializerExtensionSupport
@end

@interface FPFuelStationSerializer : HCHalJsonSerializerExtensionSupport
@end

// define our serializers
HCMediaType *fpLogMediaType = [HCMediaType mediaTypeFromString:@"application/vnd.fp.example.com-v1.0+json"];
FPFuelPurchaseLogSerializer *fpLogSerializer =
  [[FPFuelPurchaseLogSerializer alloc] initWithMediaType:fpLogMediaType
                                                 charset:[HCCharset UTF8]
                         serializersForEmbeddedResources:@{} // fplog resources will NOT have embedded resources
                             actionsForEmbeddedResources:@{}];

HCMediaType *fuelStationMediaType = [HCMediaType mediaTypeFromString:@"application/vnd.fp.example.com-v1.0+json"];
HCActionForEmbeddedResource actionForEmbeddedFpLog = ^(id fuelStation, id embeddedFpLog) {
  [(FPFuelStation *)fuelStation addFpLog:embeddedFpLog];
};
FPFuelStationSerializer *fuelStationSerializer =
  [[FPFuelStationSerializer alloc] initWithMediaType:fuelStationMediaType
                                             charset:[HCCharset UTF8]
                     serializersForEmbeddedResources:@{[fpLogMediaType description] : fpLogSerializer}
                         actionsForEmbeddedResources:@{[fpLogMediaType description] :
                         actionForEmbeddedFpLog}];

// deserialize our fuel station JSON
NSString *fuelStationJsonAsStr = ...; // assume fuelStationJsonAsStr now holds our fuel station JSON defined above
NSDictionary *fuelStationJsonAsDict =
  [NSJSONSerialization JSONObjectWithData:[fuelStationJsonAsStr dataUsingEncoding:NSUTF8StringEncoding]
                                  options:0
                                    error:nil];
HCDeserializedPair *pair = [fuelStationSerializer deserializeEmbeddedResource:fuelStationJsonAsDict];
FPFuelStation *fuelStation = [pair resourceModel];
NSDictionary *fuelStationRels = [pair relations];

HCRelationExecutor *relExec =
  [[HCRelationExecutor alloc] initWithDefaultAcceptCharset:[HCCharset UTF8]
                                     defaultAcceptLanguage:@"en-US"
                                 defaultContentTypeCharset:[HCCharset UTF8]
                                  allowInvalidCertificates:NO];
NSURL *fuelStationUrl = [[NSURL alloc]initWithString:@"/fuelstations/fs291410"
                                       relativeToURL:[NSURL URLWithString:@"https://fp.example.com"]];
HCResource *fuelStationRes = [[HCResource alloc] initWithMediaType:fuelStationMediaType
                                                               uri:fuelStationUrl];
__block FPFuelStation *fetchedFuelStation;
__block NSDictionary *fuelStationRelations;
HCGETSuccessBlk successBlk = ^(NSURL *location,
                               id resourceModel,
                               NSDate *lastModified,
                               NSDictionary *relations,
                               NSHTTPURLResponse *resp) {
  fetchedFuelStation = (FPFuelStation *)resourceModel;
  fuelStationRelations = relations;
  NSLog(@"Got the fuel station and its relations!");
};
HCRedirectionBlk redirectionBlk = ^(NSURL *location,
                                    BOOL movedPermanently,
                                    BOOL notModified,
                                    NSHTTPURLResponse *resp) {
  NSLog(@"The target resource is somewhere else!");
};
HCClientErrorBlk clientErrBlk = ^(NSHTTPURLResponse *resp) {
  NSLog(@"Client error!");
};
HCAuthReqdErrorBlk authRequiredBlk = ^(HCAuthentication *auth,
                                       NSHTTPURLResponse *resp) {
  NSLog(@"Authentication required!");
};
HCServerErrorBlk serverErrBlk = ^(NSHTTPURLResponse *resp) {
  NSLog(@"Server error!");
};
HCServerUnavailableBlk serverUnavailableBlk = ^(NSDate *retryAfter,
                                                NSHTTPURLResponse *resp) {
  NSLog(@"The server is currently unavailable!");
};
HCConnFailureBlk connFailureBlk = ^(NSInteger nsurlErr) {
  NSLog(@"Connection error!");
};
[relExec doGetForTargetResource:fuelStationRes
                ifModifiedSince:nil
               targetSerializer:fuelStationSerializer
                   asynchronous:YES // YES to put AFNetworking request op onto operationQueue; NO to directly start the operation
                completionQueue:nil // run completion block on main thread
                  authorization:nil // don't supply an 'Authorization' request header
                        success:successBlk
                    redirection:redirectionBlk
                    clientError:clientErrBlk
         authenticationRequired:authRequiredBlk
                    serverError:serverErrBlk
               unavailableError:serverUnavailableBlk
              connectionFailure:connFailureBlk
                        timeout:60
                    cachePolicy:NSURLRequestUseProtocolCachePolicy
                   otherHeaders:@{}];

HCRelation *purchaseLogsRel = [fuelStationRelations objectForKey:@"purchase_logs"];
FPFuelPurchaseLog *fpLog = [FPFuelPurchaseLog makeWithLogDate:[NSDate date]
                                              odometerReading:@(25004.2)
                                          numGallonsPurchased:@(14.7)];
HCPOSTSuccessBlk successBlk = ^(NSURL *location,
                                id resourceModel,
                                NSDate *lastModified,
                                NSDictionary *relations,
                                NSHTTPURLResponse *resp) {
  if (resourceModel) {
    FPFuelPurchaseLog *newFpLog = (FPFuelPurchaseLog *)resourceModel; // if the created fpLog is echoed back in the response
    NSLog(@"Our newly-minted fpLog instance! %@", newFpLog);
  }
};
HCAuthorization *authorization = [HCAuthorization authWithScheme:@"fp-auth"
                                             singleAuthParamName:@"fp-token"
                                                  authParamValue:@"FPAUTHTKN-0291034K-ASNLUS-ZDLSI920"];
[relExec doPostForTargetResource:[purchaseLogsRel target
              resourceModelParam:fpLog // the model object to be serialized and become the body of the request
                 paramSerializer:fpLogSerializer // serializes the resourceModelParam to be the body of the request
        responseEntitySerializer:fpLogSerializer // if present, deserializes the response into a model object
                    asynchronous:YES // to put AFNetworking request op onto operationQueue; NO to directly start the operation
                 completionQueue:nil // run completion block on main thread
                   authorization:authorization
                         success:successBlk
                     redirection:redirectionBlk
                     clientError:clientErrBlk
          authenticationRequired:authRequiredBlk
                     serverError:serverErrBlk
                unavailableError:serverUnavailableBlk
               connectionFailure:connFailureBlk
                         timeout:60
                    otherHeaders:@{}];