Swipe to delete crashes when tapped - ios

Question

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
PFObject *object = [_tdlArray objectAtIndex:(_tdlArray.count - indexPath.row -1)];
[object deleteInBackground];
//found the code for removing a row.
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationLeft];
[tableView reloadData];
[object deleteInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
if (!succeeded){
[tableView reloadData];
}
}];
}
}
I am able to successfully remove the data, but my app would crash every time I tap on the delete button. I think it has something to do with the [NSArray arrayWithObject:indexPath]
These are the error message
Assertion failure in -[UITableView _endCellAnimationsWithContext:]
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (3) must be equal to the number of rows contained in that section before the update (3), 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).'

Answer 1

You want to delete the object then reload the data. Don't dispatch asynchronously the object to be deleted then tell the tableview you're deleting rows because the object has likely not been deleted yet, hence the error you're getting. Use the callback block to update the tableview after the object has been removed that way you can be sure that the object has been deleted. Also if you have a local store of the data that not bound to the data on the server, you need to remove the object from there as well.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
//not sure how you're calculating the index here
PFObject *object = [_tdlArray objectAtIndex:(_tdlArray.count - indexPath.row -1)];
NSMutableArray *mutArray = [_tdlArray mutableCopy];
[mutArray removeObject:object];
_tdlArray = [NSArray arrayWithArray:mutArray];
[object deleteInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
if (!succeeded){
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationLeft];
[tableView reloadData];
}
}];
}
}