How to delete an object from RestKit managed object store

Question

I'm using RestKit 0.2 to get a JSON file from my server and map the objects to my CoreData stack (analog to the TwitterCoreData example).

In the first request, I get the following result: Artist1, Artist2, Artist3.

In the second request, one artist is outdated and the result looks like this: Artist1, Artist3.

Now the Artist2 should be deleted from my local store and disappear in my UITableView. However, I can't find a way to delete the Artist2 from my local storage.

How do I delete an object in RestKit 0.2 from a managed object store?

This is what I am doing:

#pragma mark - Data methods
- (void)fetchResults {
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Artists"];
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"ordernr" ascending:YES];
fetchRequest.sortDescriptors = @[descriptor];
NSError *error = nil;

// Setup fetched results
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
                                                                    managedObjectContext:[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext
                                                                      sectionNameKeyPath:nil
                                                                               cacheName:nil];
[self.fetchedResultsController setDelegate:self];
BOOL fetchSuccessful = [self.fetchedResultsController performFetch:&error];

if(fetchSuccessful){
    data = [self.fetchedResultsController fetchedObjects];
    [_tableView reloadData];
    NSLog(@"Fetched artists: %i", [[self.fetchedResultsController fetchedObjects] count]);
}
}

- (void)loadData {
[[RKObjectManager sharedManager] getObjectsAtPath:@"/artists.php" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {


     NSLog(@"Fetched artists: %i", [[mappingResult array] count]);

    for (id object in data) {
        if (NO == [[mappingResult array] containsObject:object]){
            NSLog(@"DELETE 1 object...");
            //HOW TO DELETE THE OBJECT HERE??
        }
    }

    [[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:@"ArtistsLastUpdatedAt"];
    [[NSUserDefaults standardUserDefaults] synchronize];

    [self fetchResults];

} failure:^(RKObjectRequestOperation *operation, NSError *error) {
    RKLogError(@"Load failed with error: %@", error);
}];
}

Answer 1

Try the following:

NSManagedObjectContext *context = object.managedObjectContext;

[context deleteObject:object];

NSError *error;
if (![context save:&error]) {

NSLog(@"delete error");

// Handle the error, update UI etc.

}