Random Debugging / Wrong Memory Management - iphone

Question

I have no idea what's wrong with my program...
I think something bad with the memory management, cos every time I try to execute the app i have a different result from the simulator.
When I run the app everything works fine. The date formatter works fine! I can see in the table all the cell formatted in the right way!
The interface is a tabController whit 2 tableView to show the content of a database and a tab with a view used to add element to the db.
If I go in the "Add Tab" i can add all the element I want, but when i switch back to the others tab the program crash with an "Exe_Bad_Access" (in the code below).
- (UITableViewCell *)tableView:(UITableView *)_tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [_tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
[[NSBundle mainBundle] loadNibNamed:#"MovieTableCell" owner:self options:NULL];
cell = nibLoadedCell;
}
// Configure the cell.
UILabel *itemLabel = (UILabel *) [cell viewWithTag:1];
UILabel *priceLabel = (UILabel *) [cell viewWithTag:2];
UILabel *groupLabel = (UILabel *) [cell viewWithTag:3];
UILabel *dateLabel = (UILabel *) [cell viewWithTag:4];
NSDictionary *rowVals = (NSDictionary *) [shoppingListItems objectAtIndex:indexPath.row];
NSString *itemName = (NSString *) [rowVals objectForKey:#"item"];
itemLabel.text = itemName;
int groupid = [(NSNumber *) [rowVals objectForKey:#"groupid"] intValue];
groupLabel.text = Group[groupid];
NSNumber *price = (NSNumber *) [rowVals objectForKey:#"price"];
priceLabel.text = [priceFormatter stringFromNumber: price];
NSDate *dateValue = (NSDate *) [rowVals objectForKey:#"dateadded"];
NSString *str = [dateFormatter stringFromDate:dateValue]; //-->Here I got the Bad Access
[dateLabel setText:str];
return cell;
[itemLabel release];
[groupLabel release];
[priceLabel release];
[dateLabel release];
}
Here is the entire program, if someone want to have a look: http://cl.ly/A1yk

Answer 1

3 things:
1) Anything after your return statement will not run. The 4 lines after that will never get run.
return cell;
[itemLabel release];
[groupLabel release];
[priceLabel release];
[dateLabel release];
2) If those release statements did run, the next time you access those labels you will get a bad access error, because those UILabels will get deallocated. Don't call 'release' on any object you haven't called 'retain' on.
3) To understand if anything is wrong with dateFormatter, we'd have to see every piece of code that touches that variable.

Answer 2

Look at the memory management of dateFormatter. It's may be being over released. You can check by adding a
NSLog(#"Date formatter: %#", dateFormatter);
before the string call and see what shows up.
By they way, remove the [itemLabel release] etc. lines. (a) they are not being executed as they follow your return cell and (b) if they were called, they'd cause problems.

Answer 3

Your casting NSDate to the objectAtIndex, are you sure the object is not some other class is it? Also, is the dateFormatter variable initialised as it could be nil?

Answer 4

Try removing the release lines at the end. As you are not allocating the UILabel its better not to release those. Hope this helps!

Answer 5

I cant be sure if this might be the reason, coz exc_bad_access can occur for anything. But it seems like when you are reusing the same cell, you are never allocating it urself but instead getting it as nibloaded cell from the interface builder.
Try using the default code where u alloc/init a cell:
(UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"MyCell";
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell =
[[[UITableViewCell alloc]
initWithFrame:CGRectZero
reuseIdentifier:cellIdentifier]
autorelease];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.text = label;
return cell;
}