NSFetchedResultsController not showing updates from other contexts
core-data, iphone, nsfetchedresultscontroller
Solution
Are you getting any delegate call backs from the NSFetchedResultsController? If not then this may be a bug with the NSFetchedResultsController itself. I would recommend creating a test project that can confirm/deny this issue in isolation.
If you can duplicate it in isolation;
- I would love to see it :)
- File a radar with Apple.
After reviewing the code, the answer is to change your notification observer from `NSManagedObjectContextWillSaveNotification` to `NSManagedObjectContextDidSaveNotification`. You were sending the message just before the save occurred which was causing your issues.
Problem
I have an NSFetchedResultsController set up to populate a UITableView, based off my 'main' NSManagedObjectContext. In a timer, I continually add objects into a separate NSManagedObjectContext, but one that shares its NSPersistantStoreCoordinator with the main context. I can see NSManagedObjectContextWillSaveNotification notifications being sent, and when I quit an restart the app, I have all the data from the previous run. However, no updates happen to the current NSFetchedResultsController. I've created a test project and placed it here. (I initially thought this was happening due to there being multiple threads at play; however, it happens when everything is done in one thread). Original Question I have an NSFetchedResultsController set up to populate a UITableView, based off my 'main' NSManagedObjetContext. In a background thread, I download and import several objects into a separate NSManagedObjectContext, but one that shares its NSPersistantStoreCoordinator with the main thread's context. I am registered to receive NSManagedObjectContextWillSaveNotification notifications. When I get these, I forward them on to the main thread, and pass them to my main context. Using the debugger, I can watch these come in, and verify that they are, indeed, adding objects to the context. However, my NSFetchedResultsController is not updating. If I do this all in the main thread, it does work. Calling -performFetch: on the controller will cause it to update, so I know it's not that it's not seeing the new objects. Most of this is boilerplate code, just split into different threads.