iOS - NSRangeException only when breakpoints are disabled - objective-c

Question

Recently started developing apps, so excuse my ignorance. I have a tableView, and when a cell in the table view is clicked, I want to insert a new row directly below it. This currently works in my code. However, I also want the row that has been inserted to be removed once the cell has been clicked again. This is giving me the NSRangeException saying I am out of bounds in my array.
I figured this probably has to do with my tableView delegate/data methods, so I set up break points at each of them. With the break points enabled, the cell is removed perfectly. However, when I disable the breakpoints, and let the application run on its own, it crashes. How could break points possibly be affecting this?
Here is the relevant code:
- (NSInteger) numberOfSectionsInTableView:(UITableView *)songTableView{
return 1;
}
- (NSInteger)tableView:(UITableView *)songTableView
numberOfRowsInSection:(NSInteger)section{
bool debug = false;
if (debug) NSLog(#"--TableView: rankings");
if (expandedRow == -1)
return [self.songs count];
else //one row is expanded, so there is +1
return ([self.songs count]+1);
}
- (UITableViewCell *)tableView:(UITableView *)songTableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath{
bool debug = false;
if (debug) NSLog(#"--tableView: tableView");
NSUInteger row = [indexPath row];
if (row == expandedRow){ //the expanded row, return the custom cell
UITableViewCell *temp = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"test"];
return temp;
}
UITableViewCell *cell = [tableViewCells objectAtIndex:row];
return cell;
}
}
- (NSString *)tableView:(UITableView *)songTableView
titleForHeaderInSection:(NSInteger)section{
//todo: call refresh title
return #"The Fresh List";
}
- (CGFloat)tableView:(UITableView *)songTableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 44.0; //same as SongCell.xib
}
- (void)tableView: (UITableView *)songTableView
didSelectRowAtIndexPath: (NSIndexPath *)indexPath {
bool debug = true;
//todo: if the user selects expanded cell, doesn't do anything
SongCell *cell = (SongCell *)[songTableView cellForRowAtIndexPath:indexPath];
if (cell->expanded == NO){
//change cell image
cell.bgImage.image = [UIImage imageNamed:#"tablecellbg_click.png"];
cell->expanded = YES;
//add new cell below
NSInteger atRow = [indexPath row] + 1;
NSIndexPath *insertAt = [NSIndexPath indexPathForRow:atRow inSection:0];
NSArray *rowArray = [[NSArray alloc] initWithObjects:insertAt, nil];
if (debug) NSLog(#"Expanded row: %d", atRow);
expandedRow = atRow;
[tableView insertRowsAtIndexPaths:rowArray withRowAnimation:UITableViewRowAnimationTop];
}else { //cell is already open, so close it
//change cell image
cell.bgImage.image = [UIImage imageNamed:#"tablecellbg.png"];
cell->expanded = NO;
NSIndexPath *removeAt = [NSIndexPath indexPathForRow:expandedRow inSection:0];
NSArray *rowArray = [[NSArray alloc] initWithObjects:removeAt, nil];
if(debug) NSLog(#"--about to delete row: %d", expandedRow);
expandedRow = -1;
[tableView deleteRowsAtIndexPaths:rowArray withRowAnimation:UITableViewRowAnimationTop];
//remove expaned cell below
}
}

Answer 1

This is just a guess, but it's a good idea to wrap code that changes the table structure in calls to
[tableView beginUpdates];
[tableView endUpdates];

Answer 2

I bet this returns null: [NSIndexPath indexPathForRow:expandedRow inSection:0]; and if it does it blows ...
hth

Answer 3

I hate to answer my own questions but I figured it out.
I was loading up my tableView from an array of objects. When I added the cell, that array still only held 30 objects, whereas my table held 31. I was correctly returning the numberOfRowsInSection method.
Here is the modification I made. Notice the extra else if:
NSUInteger row = [indexPath row];
if (row == expandedRow){ //the expanded row, return the custom cell
if(debug) NSLog(#"row == expandedRow");
UITableViewCell *temp = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"test"];
return temp;
}
else if (expandedRow != -1 && row > expandedRow)
row--;
My array of objects and the UITableViewCells were suppose to match up 1-1. After the expanded row, indexPath's row because off by 1. Here is my quick fix to this problem, although I'm sure there is a better way to solve this.