RestKit Mapping for different web services in different view controllers

[ghost]

I am developing an iPad App. I have three different view controllers wherein I call three different web services using RestKit and map them to core data entity. I display the data in all view controllers by using NSFetchedResultsController.

First time when I try to load the data, it works correctly on all the view controllers. Later when I come up to the first view controller and try to load the data, it fails. I feel I am messing something.

Here is my code. In AppDelegate, I initialize RestKit:

RKObjectManager *objectManager = [RKObjectManager managerWithBaseURL:baseURL];

//[RKObjectManager setSharedManager:objectManager];
[RKObjectManager setSharedManager:objectManager];

// Initialize managed object model from bundle
NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];

// Initialize managed object store
RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
objectManager.managedObjectStore = managedObjectStore;

// Complete Core Data stack initialization
[managedObjectStore createPersistentStoreCoordinator];
NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"StockTakeDB.sqlite"];
NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"StoreItemsDB" ofType:@"sqlite"];
NSError *error;
NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:seedPath withConfiguration:nil options:nil error:&error];
NSAssert(persistentStore, @"Failed to add persistent store with error: %@", error);

// Create the managed object contexts
[managedObjectStore createManagedObjectContexts];

// Configure a managed object cache to ensure we do not create duplicate objects
managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];

viewStockRestKitManagedObjectContext = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
takeStockRestKitManagedObjectContext = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
takeStockItemsByLocationRestKitManagedObjectContext = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
In the first view controller, I setup mapping and other required things as shown below:

RKObjectManager *objectManager = [RKObjectManager sharedManager];

// Initialize managed object model from bundle
NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];

// Initialize managed object store
RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
objectManager.managedObjectStore = managedObjectStore;

//Complete Core Data stack initialization
[managedObjectStore createPersistentStoreCoordinator];
NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"StockTakeDB.sqlite"];
NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"StoreItemsDB" ofType:@"sqlite"];
NSError *error;
NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:seedPath withConfiguration:nil options:nil error:&error];
NSAssert(persistentStore, @"Failed to add persistent store with error: %@", error);

// Create the managed object contexts
[managedObjectStore createManagedObjectContexts];

// Configure a managed object cache to ensure we do not create duplicate objects
managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];

[objectManager addFetchRequestBlock:^NSFetchRequest *(NSURL *URL) {
RKPathMatcher *pathMatcher = [RKPathMatcher pathMatcherWithPattern:viewStockRequestPath];

NSDictionary *argsDict = nil;
BOOL match = [pathMatcher matchesPath:[URL relativePath] tokenizeQueryStrings:NO parsedArguments:&argsDict];

if (match) {
    NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"StoreItems"];
    return fetchRequest;
}

return nil;

}];

RKEntityMapping *storeItemsListMapping = [RKEntityMapping mappingForEntityForName:@"StoreItems" inManagedObjectStore: managedObjectStore];
storeItemsListMapping.identificationAttributes = @[@"itemId"];

[storeItemsListMapping addAttributeMappingsFromDictionary:
@{
@"itemId" : @"itemId",
@"itemName" : @"itemName",
@"itemCode" : @"itemCode",
@"uomCode" : @"uomCode",
@"locId" : @"locId",
@"locName" : @"locName",
@"subLocId" : @"subLocId",
@"subLocName" : @"subLocName",
@"storeItemId" : @"storeItemId"
}
];

RKResponseDescriptor *storeItemsListResponseDescriptor =
[RKResponseDescriptor responseDescriptorWithMapping:storeItemsListMapping
method:RKRequestMethodGET
pathPattern:nil
keyPath:nil
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];

[objectManager addResponseDescriptor:storeItemsListResponseDescriptor];
Then I am getting the Objects:

[[RKObjectManager sharedManager]
getObjectsAtPath:viewStockRequestPath
parameters:nil
success: ^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSLog(@"requestDataItemsForStore - Mapping Success");
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"StoreItems"];

NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"locName" ascending:YES];
fetchRequest.sortDescriptors = @[descriptor];

NSError *error = nil;
[[appDelegate viewStockRestKitManagedObjectContext] executeFetchRequest:fetchRequest error:&error];
NSError *error;
if (![[self fetchedResultsController] performFetch:&error]) {
}
[self.tableView reloadData];
}
failure: ^(RKObjectRequestOperation *operation, NSError *error) {
RKLogError(@"Load failed with error: %@", error);
NSLog(@"requestDataItemsForStore - Loading Failed");
}
];
and here is the fetchedresultscontroller code:

• (NSFetchedResultsController *)fetchedResultsController {
  if (viewStockFetchedResultsController != nil) {
  return viewStockFetchedResultsController;
  }

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"StoreItems" inManagedObjectContext:[appDelegate viewStockRestKitManagedObjectContext]];
[fetchRequest setEntity:entity];
NSSortDescriptor *rackNameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"locName" ascending:YES];
NSArray *sortDescriptors = @[rackNameDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
viewStockFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[appDelegate viewStockRestKitManagedObjectContext] sectionNameKeyPath:@"locName" cacheName:nil];
viewStockFetchedResultsController.delegate = self;
return viewStockFetchedResultsController;
}

I have same code repeated in every view controller.

Can you help me to identify the issue?

[segiddins]

This sort of usage question belongs on stack overflow, sorry.