Question

I have a table being generated from an array of NSManagedObjects.
This works fine until I try to add an extra cell at the top of the table.

Here is what I’m trying at the moment:

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    int menuLength = [mainMenu count] + 1;
    return menuLength;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    // Check for reusable cell
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: @"UITableViewCell"];


    // If no reusable cell, create one
    if (!cell) {
        cell = [[[UITableViewCell alloc] initWithStyle: UITableViewCellStyleDefault
                                   reuseIdentifier: @"UITableViewCell"] autorelease];
    }

    // Set the text on the cell with the genus name that is at the nth index of generaList
    if ([indexPath row] == 0) {
        [[cell textLabel] setText: @"All"];
    } else {
        NSManagedObject *filter = [mainMenu objectAtIndex: [indexPath row]];
        [[cell textLabel] setText: [filter valueForKey: @"filter_label"]];
    }
    return cell;
}

When I try to scroll through the table, it throws the following exception:

‘NSRangeException’, reason: ‘* -[_PFArray objectAtIndex:]: index (9) beyond bounds (9)’

Any help would be much appreciated!

Answer 1

Try this:

int row = [indexPath row];
if (row == 0) {
    [[cell textLabel] setText: @"All"];
} 
else {
   NSManagedObject *filter = [mainMenu objectAtIndex: row-1];

The important change here is subtracting one from row before putting it into objectAtIndex — I think your failure to do so is what is giving you the exception, as it looks for the object at index 9 in mainMenu.

The setting up of row as its own variable is a good idea whenever you are using something more than once. And in this case, it might have helped you notice your bug more easily.