Saving the edited UITableView Rows - ios

Question

So basically I have a table view of folder objects and I want to be able to remove/ delete folders. So far if I try to delete, the folders are removed, but when I re run the application they are all back (so the delete is not saved). Any advice?
here is my delete method for the UITableView:
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source
[self.folders removeObjectAtIndex:indexPath.row];
NSMutableArray *newSavedFolders = [[NSMutableArray alloc] init];
for (Folder *folder in self.folders){
[newSavedFolders addObject:[self folderWithName:folder.name]];
}
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
} else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
and the folderWithName method is from here:
- (Folder *)folderWithName:(NSString *)name {
id delegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [delegate managedObjectContext];
Folder *folder = [NSEntityDescription insertNewObjectForEntityForName:#"Folder" inManagedObjectContext:context];
folder.name = name;
folder.date = [NSDate date];
NSError *error;
if (![context save:&error]) {
//we have an error
}
return folder;
}

Answer 1

The reason it deletes is because of this line:
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
That removes the row from view, but doesn't remove the data.
If your using CoreData then you simply do the following with a NSFetchedResultsController:
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
[self.tableView reloadData];
NSError *error = nil;
if (![context save:&error]) {
NSLog(#"Can't Delete! %# %#", error, [error localizedDescription]);
return;
}
} else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
Add call your items with the NSFetchedResultsController this way:
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Folder" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number for displaying in UITableView.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
NSArray *sortDescriptors = #[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return fetchedResultsController;
}