UITableView Alphabetizing - objective-c

Question

I have a UITableView that is successfully populated from a database, put into a NSArray and every cell is clickable and performs the correct action when selected, however the list is out of alphabetical order. In order to sort them into alphabetical order, I use the following code:
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:#"Name" ascending:YES];
sortedArray = [buildings sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];
The alphabetizing works correctly, however when some of the cells (in this example it was the first cell in the list) are clicked the app terminates with an uncaught exception:
'NSRangeException' '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]'
I'd be happy to post more code excerpts, I am just unsure of what relevant information would be needed to help answer this question.
Edit:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSInteger r = [indexPath row];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
if(infoInst != nil) {
infoInst = nil;
}
infoInst = [[DirInfoListing alloc] initWithNibName:#"DirInfoListing" bundle:nil building:[self.listData objectAtIndex:r] map:mapUI];
NSLog(#"infoInst building: %#", [self.listData objectAtIndex:r]);
NSString *deviceType = [UIDevice currentDevice].model;
if([deviceType isEqualToString:#"iPad"] || [deviceType isEqualToString:#"iPad Simulator"]){
[self presentModalViewController:infoInst animated:YES];
} else {
[self.navigationController pushViewController:infoInst animated:YES];
}
}
Edit: Here is the stack trace immediately before the error is thrown
2013-07-03 16:56:56.579 thestanforddaily[32907:1a303] Stack trace : (
0 thestanforddaily 0x002190d9 -[Directory tableView:didSelectRowAtIndexPath:] + 457
1 UIKit 0x01ae871d -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 1164
2 UIKit 0x01ae8952 -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 201
3 Foundation 0x0237086d __NSFireDelayedPerform + 389
4 CoreFoundation 0x02acd966 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
5 CoreFoundation 0x02acd407 __CFRunLoopDoTimer + 551
6 CoreFoundation 0x02a307c0 __CFRunLoopRun + 1888
7 CoreFoundation 0x02a2fdb4 CFRunLoopRunSpecific + 212
8 CoreFoundation 0x02a2fccb CFRunLoopRunInMode + 123
9 GraphicsServices 0x0327b879 GSEventRunModal + 207
10 GraphicsServices 0x0327b93e GSEventRun + 114
11 UIKit 0x01a58a9b UIApplicationMain + 1175
12 thestanforddaily 0x00002f4d main + 141
13 thestanforddaily 0x00002e75 start + 53
)
2013-07-03 16:57:13.740 thestanforddaily[32907:1a303] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]'
*** First throw call stack:
(0x2af9052 0x28e8d0a 0x2ae5db8 0x21cb0e 0x1b1e64e 0x1b1e941 0x1b3047d 0x1b3066f 0x1b3093b 0x1b313df 0x1b31986 0x1b315a4 0x219250 0x1ae871d 0x1ae8952 0x237086d 0x2acd966 0x2acd407 0x2a307c0 0x2a2fdb4 0x2a2fccb 0x327b879 0x327b93e 0x1a58a9b 0x2f4d 0x2e75)
Thank you!

Answer 1

The only array access I see in didSelectRowAtIndexPath is [self.listData objectAtIndex:r]. So it would seem your listData array isn't in sync with the table's data model. From the code you posted, the array sortedArray should correspond to the data model, so make sure listData and sortedArray are kept in sync or just have one array. If you still can't figure it out, please post your UITableViewDataSource methods as well as the methods where you set up your various array variables.

Answer 2

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:#"Name" ascending:YES];
sortedArray = [buildings count] <= 1 ? buildings : [buildings sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];
Unless you require sortedArray to be a different instance than buildings. Then you should change the statement accordingly.