iPhone: Requesting cellforrow for rows out of bounds - iphone

Question

What did I do wrong? I just modified the Navigation Based application code a bit to read and display a JSON string. It crashes when I scroll up the list with the message Objc_msgSend and points at this as the problem: cell.textLabel.text=[[locations objectAtIndex: storyIndex] objectForKey: #"title"];
#import "RootViewController.h"
#import "JSON.h"
#implementation RootViewController
#synthesize locations;
- (NSString *)stringWithUrl:(NSURL *)url
{
// Construct a String around the Data from the response
return [[NSString alloc] initWithContentsOfURL:url];
}
-(void)jsonLoad {
NSURL *URL = [NSURL URLWithString:#"http://bombaytokyo.com/whrru/jsonexample.html"];
NSString *jsonstring = [self stringWithUrl:URL];
NSLog(jsonstring);
locations = [jsonstring JSONValue];
[jsonstring release];
}
- (void)viewDidLoad {
[super viewDidLoad];
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
[self jsonLoad];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
[locations release];
}
- (void)viewDidUnload {
// Release anything that can be recreated in viewDidLoad or on demand.
// e.g. self.myOutlet = nil;
}
#pragma mark Table view methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// return 0;
return [locations count];
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1];
NSLog(#"Index Path: %i",indexPath);
//NSLog(title);
cell.textLabel.text=[[locations objectAtIndex: storyIndex] objectForKey: #"title"];
return cell;
}
- (void)dealloc {
[super dealloc];
}
#end

Answer 1

0 based arrays, id length is 0 the 0 - 1 = -1 this will obviously cause an exception.
[indexPath indexAtPosition: [indexPath length] - 1]
change to
[indexPath indexAtPosition: [indexPath length]]
and are you sure you dont want indexPath.row. it looks like you are just returning the length each time.

Answer 2

solution:
self.locations = [jsonstring JSONValue];
Thanks for all the suggestions.