TableView row removal with NSFetchedResultsController crashing? - uitableview

Question

I'm trying to let users delete a row from a UITableView that's populated using a NSFetchedResultsController but keep getting a fatal error:
Terminating app due to uncaught exception
'NSInternalInconsistencyException', reason: 'Invalid update: invalid
number of rows in section 1. The number of rows contained in an
existing section after the update (7) must be equal to the number of
rows contained in that section before the update (7), plus or minus
the number of rows inserted or deleted from that section (0 inserted,
1 deleted) and plus or minus the number of rows moved into or out of
that section (0 moved in, 0 moved out).'
I'm deleting the core data entry and then deleting the row in the tableView in my code but still get the error above:
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
self.feedTable.beginUpdates()
let event = self.fetchedResultsController.object(at: indexPath) as Event
self.managedObjectContext.delete(self.fetchedResultsController.object(at: indexPath))
do {
try self.managedObjectContext.save()
} catch {}
self.feedTable.deleteRows(at: [indexPath], with: .automatic)
self.feedTable.endUpdates()
}
}
Can anybody help understand what I'm doing wrong?

Answer 1

If you use a fetched results controller. Only delete the object with
self.managedObjectContext.delete(self.fetchedResultsController.object(at: indexPath))
Try this solution
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
let event = self.fetchedResultsController.object(at: indexPath) as Event
self.managedObjectContext.delete(self.fetchedResultsController.object(at: indexPath))
do {
try self.managedObjectContext.save()
} catch {}
}
}
You don't need beginUpdates and endUpdates