- I populate and
save:an initialNSManagedObjectContext - setup an
NSFetchedResultsControllerwith a differentNSManagedObjectContext, which filters on aboolean"show" attribute. - Finally update "show" on yet another
NSManagedObjectContextandsave:.
I expect that this should cause my NSFetchedResultsController to call NSFetchedResultsControllerDelegate's controllerDidChangeContent:. I never get that call. NSFetchedResultsController with predicate ignores changes merged from different NSManagedObjectContext's accepted answer indicates that in addition to controllerDidChangeContent:, I should get an NSManagedObjectContextObjectsDidChangeNotification, but I don't receive that either.
A complete code example is included below and on github. I've filed a radar with Apple.
@interface HJBFoo : NSManagedObject
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSNumber *show;
@end
@interface HJBAppDelegate () <NSFetchedResultsControllerDelegate>
@property (nonatomic, strong) NSPersistentStoreCoordinator *persistentStoreCoordinator;
@property (nonatomic, strong) NSManagedObjectContext *initialManagedObjectContext;
@property (nonatomic, strong) NSManagedObjectContext *fetchedResultsControllerManagedObjectContext;
@property (nonatomic, strong) NSFetchedResultsController *fetchedResultsController;
@end
@implementation HJBAppDelegate
#pragma mark - UIApplicationDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.backgroundColor = [UIColor whiteColor];
self.window.rootViewController = [UIViewController new];
NSAttributeDescription *nameAttributeDescription = [NSAttributeDescription new];
[nameAttributeDescription setAttributeType:NSStringAttributeType];
[nameAttributeDescription setIndexed:NO];
[nameAttributeDescription setOptional:NO];
[nameAttributeDescription setName:@"name"];
NSAttributeDescription *showAttributeDescription = [NSAttributeDescription new];
[showAttributeDescription setAttributeType:NSBooleanAttributeType];
[showAttributeDescription setIndexed:YES];
[showAttributeDescription setOptional:NO];
[showAttributeDescription setName:@"show"];
NSEntityDescription *fooEntityDescription = [NSEntityDescription new];
[fooEntityDescription setManagedObjectClassName:@"HJBFoo"];
[fooEntityDescription setName:@"HJBFoo"];
[fooEntityDescription setProperties:@[
nameAttributeDescription,
showAttributeDescription,
]];
NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel new];
[managedObjectModel setEntities:@[
fooEntityDescription,
]];
self.persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:managedObjectModel];
NSError *error = nil;
if ([self.persistentStoreCoordinator addPersistentStoreWithType:NSInMemoryStoreType
configuration:nil
URL:nil
options:nil
error:&error]) {
self.initialManagedObjectContext = [NSManagedObjectContext new];
[self.initialManagedObjectContext setPersistentStoreCoordinator:self.persistentStoreCoordinator];
HJBFoo *foo1 = [NSEntityDescription insertNewObjectForEntityForName:@"HJBFoo"
inManagedObjectContext:self.initialManagedObjectContext];
foo1.name = @"1";
foo1.show = @YES;
HJBFoo *foo2 = [NSEntityDescription insertNewObjectForEntityForName:@"HJBFoo"
inManagedObjectContext:self.initialManagedObjectContext];
foo2.name = @"2";
foo2.show = @NO;
error = nil;
if ([self.initialManagedObjectContext save:&error]) {
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"HJBFoo"];
[fetchRequest setReturnsObjectsAsFaults:NO];
error = nil;
NSArray *initialFoos = [self.initialManagedObjectContext executeFetchRequest:fetchRequest
error:&error];
if (initialFoos) {
NSLog(@"Initial: %@", initialFoos);
self.fetchedResultsControllerManagedObjectContext = [NSManagedObjectContext new];
[self.fetchedResultsControllerManagedObjectContext setPersistentStoreCoordinator:self.persistentStoreCoordinator];
NSFetchRequest *shownFetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"HJBFoo"];
[shownFetchRequest setPredicate:[NSPredicate predicateWithFormat:@"show == YES"]];
[shownFetchRequest setSortDescriptors:@[
[NSSortDescriptor sortDescriptorWithKey:@"name"
ascending:YES],
]];
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:shownFetchRequest
managedObjectContext:self.fetchedResultsControllerManagedObjectContext
sectionNameKeyPath:nil
cacheName:nil];
self.fetchedResultsController.delegate = self;
error = nil;
if ([self.fetchedResultsController performFetch:&error]) {
NSLog(@"Initial fetchedObjects: %@", [self.fetchedResultsController fetchedObjects]);
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(managedObjectContextDidSave:)
name:NSManagedObjectContextDidSaveNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(managedObjectContext2ObjectsDidChange:)
name:NSManagedObjectContextObjectsDidChangeNotification
object:self.fetchedResultsControllerManagedObjectContext];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.5 * NSEC_PER_SEC),
dispatch_get_main_queue(),
^(void){
NSManagedObjectContext *managedObjectContext3 = [NSManagedObjectContext new];
[managedObjectContext3 setPersistentStoreCoordinator:self.persistentStoreCoordinator];
NSFetchRequest *foo2FetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"HJBFoo"];
[foo2FetchRequest setFetchLimit:1];
[foo2FetchRequest setPredicate:[NSPredicate predicateWithFormat:@"name == %@",
@"2"]];
NSError *editingError = nil;
NSArray *editingFoos = [managedObjectContext3 executeFetchRequest:foo2FetchRequest
error:&editingError];
if (editingFoos) {
HJBFoo *editingFoo2 = [editingFoos objectAtIndex:0];
editingFoo2.show = @YES;
editingError = nil;
if ([managedObjectContext3 save:&editingError]) {
NSLog(@"Save succeeded. Expected (in order) managedObjectContextDidSave, controllerDidChangeContent, managedObjectContext2ObjectsDidChange");
} else {
NSLog(@"Editing save failed: %@ %@", [error localizedDescription], [error userInfo]);
}
} else {
NSLog(@"Editing fetch failed: %@ %@", [error localizedDescription], [error userInfo]);
}
});
} else {
NSLog(@"Failed initial fetch: %@ %@", [error localizedDescription], [error userInfo]);
}
} else {
NSLog(@"Failed to performFetch: %@ %@", [error localizedDescription], [error userInfo]);
}
} else {
NSLog(@"Failed to save initial state: %@ %@", [error localizedDescription], [error userInfo]);
}
} else {
NSLog(@"Failed to add persistent store: %@ %@", [error localizedDescription], [error userInfo]);
}
[self.window makeKeyAndVisible];
return YES;
}
#pragma mark - NSFetchedResultsControllerDelegate
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
NSLog(@"controllerDidChangeContent: %@",
[self.fetchedResultsController fetchedObjects]);
}
#pragma mark - notifications
- (void)managedObjectContextDidSave:(NSNotification *)notification {
NSManagedObjectContext *managedObjectContext = [notification object];
if (([managedObjectContext persistentStoreCoordinator] == self.persistentStoreCoordinator) &&
(managedObjectContext != self.fetchedResultsControllerManagedObjectContext)) {
NSLog(@"managedObjectContextDidSave: %@", notification);
[self.fetchedResultsControllerManagedObjectContext mergeChangesFromContextDidSaveNotification:notification];
}
}
- (void)managedObjectContext2ObjectsDidChange:(NSNotification *)notification {
NSLog(@"managedObjectContext2ObjectsDidChange: %@", notification);
}
@end
@implementation HJBFoo
@dynamic name;
@dynamic show;
@end
