NSFetchedResultsController returning nil for indexPathForObject

Question

I have my FetchedResultsController (FRC) set up like this:

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

NSEntityDescription *entity = [NSEntityDescription entityForName:@"MTWMeeting" inManagedObjectContext:[NSManagedObjectContext MR_defaultContext]];
[fetchRequest setEntity:entity];

NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"meetingDay.dayTimestamp" ascending:YES];
NSSortDescriptor *sort2 = [[NSSortDescriptor alloc] initWithKey:@"meetingTimestamp" ascending:YES];
[fetchRequest setSortDescriptors:@[sort, sort2]];

NSFetchedResultsController *theFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[NSManagedObjectContext MR_defaultContext] sectionNameKeyPath:@"meetingDay.dayTimestamp" cacheName:nil];
self.fetchedResultsController = theFetchedResultsController;

My DB is deadly simple - I have a MTWMeeting entity and a MTWDay entity that can have many meetings. Each meeting can have only 1 parent day.

My table view is setup with headers by 1 MTWDay entity for 1 section.

Now I need to scroll to a specific index in that cell.

I'm doing it like this:

MTWDay *targetDay = [MTWCoreDataManager suitableDayForMeetingWithTimestamp:[date timeIntervalSince1970]];
MTWMeeting *ourMeeting = [targetDay.dayMeetings anyObject];

NSIndexPath *ourPath = [self.fetchedResultsController indexPathForObject:ourMeeting];
NSIndexPath *tmpPath = [NSIndexPath indexPathForRow:0 inSection:ourPath.section];

Now, no matter what I do, ourPathindex path is always nil. However, MTWDay and MTWMeeting objects are real Core Data objects that I get from the core data stack.

What are my steps to get out of this behaviour? I've been struggling with this issue for days without any chance.

EDIT:

Here's an example printout of the ourMeeting Core Data object used in the code above:

<MTWDay: 0x1742a8d00> (entity: MTWDay; id: 0xd000000001780008 <x-coredata://B0F694E1-7A45-4D1E-BB26-6F0A929A135D/MTWDay/p94> ; data: {
    dayDisplayTitle = "\U0432\U043e\U0441\U043a\U0440\U0435\U0441\U0435\U043d\U044c\U0435";
    dayEvents = "<relationship fault: 0x170230da0 'dayEvents'>";
    dayID = nil;
    dayMeetings =     (
        "0xd000000003440002 <x-coredata://B0F694E1-7A45-4D1E-BB26-6F0A929A135D/MTWMeeting/p209>"
    );
    dayNumericID = 16;
    dayTimestamp = "1.416089e+09";
    daysMonth = "0xd000000000140006 <x-coredata://B0F694E1-7A45-4D1E-BB26-6F0A929A135D/MTWMonth/p5>";
})

Answer 1

Have you performed the fetch without an error?

NSError *error;
[self.fetchedResultsController performFetch:&error];

If you have, check that ourMeeting is in self.fetchedResultsController.fetchedObjects

Answer 2

Your fetched results controller is set up without predicates so that it fetches all meetings, therefore the meeting in question should be in the FRC's fetchedObjects.

Within the limits of the provided code you can check:

• is targetDay nil?
• is targetDay.dayMeetings an empty NSSet?
• is the fetched results controller nil?
• did you forget to call performFetch on the FRC?
• did you check that the FRC's context is the same as the one from which you get the object?
• are you getting object from the same fetched results controller you are using to place it?