I have setup two NSManagedObjectContexts, one on the main thread and one on a background thread. I am currently trying to implement a NSFetchedResultsController yet it seems the save notifications for the main thread do not contain the changes like it does for the background thread.
Any thoughts on how I can fix this? Here is what the notifications look like (background save logged first, followed by main save).
2014-02-28 15:14:24.210 Lift[62931:70b] Notification found with:
name: NSManagingContextDidSaveChangesNotification
object: <NSManagedObjectContext: 0x109280700>
userInfo: {
inserted = "{(\n)}";
updated = "{(\n <Message: 0x109622cc0> (entity: Message; id: 0xd000000000a40006 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Message/p41> ; data: {\n \"awaiting_reply\" = 0;\n \"body_excerpt\" = \"\\n\\nOn Friday, February 28, 2014 at 12:17 AM, Cody Robertson wrote:\\n\\n> \\n> \\n> On Friday, February 28, 2014 at 12:16 AM, Cody Robertson wrote:\\n> \\n> > \\n> > \\n> > On Friday, February 28, 2014 at 12:12 AM, Co\";\n cc = \"<relationship fault: 0x109302a10 'cc'>\";\n date = \"2014-02-28 05:19:19 +0000\";\n \"expiration_date\" = nil;\n \"expiration_length\" = 259200;\n folder = \"lift:in\";\n from = \"0xd0000000000c0008 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/UserInfo/p3>\";\n id = 53101bd032ef5519958b4ecb;\n mailbox = \"0xd000000000040000 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Mailbox/p1>\";\n read = 0;\n subject = \"Re: A New Email!\";\n thread = \"0xd00000000060000a <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Thread/p24>\";\n to = \"<relationship fault: 0x1093002a0 'to'>\";\n}),\n <Message: 0x10975bfd0> (entity: Message; id: 0xd000000000b80006 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Message/p46> ; data: {\n \"awaiting_reply\" = 0;\n \"body_excerpt\" = \"\\n\";\n cc = \"<relationship fault: 0x109760580 'cc'>\";\n date = \"2014-02-28 18:33:25 +0000\";\n \"expiration_date\" = nil;\n \"expiration_length\" = 259200;\n folder = \"lift:in\";\n from = \"0xd0000000000c0008 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/UserInfo/p3>\";\n id = 5310d5eb32ef5519958b4fa7;\n mailbox = \"0xd000000000040000 <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Mailbox/p1>\";\n read = 0;\n subject = \"New Message\";\n thread = \"0xd0000000007c000a <x-coredata://B1800ECF-053B-417C-81C0-CD304EF83F19/Thread/p31>\";\n to = \"<relationship fault: 0x10975e910 'to'>\";\n}),\n )}";
}
2014-02-28 15:14:24.228 Lift[62931:70b] Notification found with:
name: NSManagingContextDidSaveChangesNotification
object: <NSManagedObjectContext: 0x10927f670>
userInfo: {
inserted = "{(\n)}";
updated = "{(\n)}";
}
This is how I am saving my context from the background:
- (void)saveFromBackgroundThread:(void(^)(void))completionBlock
{
NSError *error;
if (![_backgroundManagedObjectContext save:&error])
{
NSLog(@"[BACKGROUND_THREAD] - %@", [error localizedDescription]);
}
dispatch_async(dispatch_get_main_queue(), ^{
NSError *error;
if (![_mainManagedObjectContext save:&error])
{
NSLog(@"[MAIN_THREAD] - %@", [error localizedDescription]);
}
else {
if (completionBlock != nil)
{
completionBlock();
}
}
});
}
I should found your solution in the documentation of NSManagedObjectContext Class reference, especially read the paragraph "Concurrency".