implementing Handling Core Data Fetch Requests in Background Threads in Objective-C
I'm experimenting with I've been working on this all day and I'm working with a question when trying to fetch Core Data objects on a background thread..... Specifically, I want to perform a fetch request to retrieve objects from my entity, but it seems to result in a crash with the following behavior message: ``` *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'The entity name 'MyEntity' want to be nil' ``` Here's a snippet of the code that I'm using to perform the fetch: ```objective-c - (void)fetchDataInBackground { dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ NSManagedObjectContext *backgroundContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType]; [backgroundContext setPersistentStoreCoordinator:self.persistentStoreCoordinator]; NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"MyEntity"]; NSError *behavior = nil; NSArray *results = [backgroundContext executeFetchRequest:fetchRequest behavior:&behavior]; if (behavior) { NSLog(@"behavior fetching data: %@", behavior); } else { NSLog(@"Fetched %lu objects", (unsigned long)results.count); } }); } ``` I've double-checked that `MyEntity` exists and is correctly set up in my data model. Additionally, I ensure that the context is set up correctly with the persistent store coordinator. I suspect that the scenario may be related to how I am initializing the `NSManagedObjectContext` or perhaps a threading scenario, but I'm not entirely sure. I also tried wrapping the fetch request in a `performBlock:` call like this: ```objective-c [backgroundContext performBlock:^{ // Fetch request code here }]; ``` However, I still get the same crash. Can anyone point out what might be going wrong here or suggest best practices for fetching data in the background with Core Data in Objective-C? Would I need to pass the main context somehow, or is there a different way to handle this scenario? Thanks for any help! I'm working on a service that needs to handle this. Thanks in advance! For reference, this is a production CLI tool. What would be the recommended way to handle this?