Question

I’m making an app which tries to read the information from the .plist file (put there parsed JSON).

The reading from file flows nice: got the array of dictionaries, but while trying to display it on tableview, the problems start. The initial view is loaded properly, but when I start scrolling, the app crashes.

#define DOCUMENTS [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]

- (void)viewDidLoad
{
    [super viewDidLoad];    
    NSString *filePathDocArray = [DOCUMENTS stringByAppendingPathComponent:@"filters.plist"];
    NSString *filePathBundleArray = [[NSBundle mainBundle] pathForResource:@"filters" ofType:@"plist"];

    if (![[NSFileManager defaultManager] fileExistsAtPath:filePathDocArray]) {
        [[NSFileManager defaultManager] copyItemAtPath:filePathBundleArray toPath:filePathDocArray error:nil];
        NSLog(@"File saved");
    } else {
        NSLog(@"File already exists");
        filters = [NSArray arrayWithContentsOfFile:filePathDocArray];
    }

}

Here I get all the info I need into filters array (checked by looping). Then:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [filters count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *myIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:myIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:myIdentifier];                              
    }

    NSInteger crow = indexPath.row;
    NSDictionary *story = [filters objectAtIndex: crow];
    cell.textLabel.text = [story objectForKey:@"Name"];
    cell.detailTextLabel.text = [story objectForKey:@"Description"];
    return cell;
}
@end

When the app starts everething is OK: I see the normel table view, but when I start scrolling it crashes

After series of breakpoint debugs I evaluated, that after the applications starts on Simulator, the link on array filters screws, so when I try to populate the next cell, the story dictionary can’t be properly created.

What sort of problem it can be?

Here the console report:

2012-09-22 13:37:43.545 JSONExample[4559:207] -[__NSCFString
objectAtIndex:]: unrecognized selector sent to instance 0x6a083c0

2012-09-22 13:37:43.547 JSONExample[4559:207] *** Terminating app due
to uncaught exception 'NSInvalidArgumentException', reason:
'-[__NSCFString objectAtIndex:]: unrecognized selector sent to
instance 0x6a083c0'

Answer 1

are you using ARC??
if not then autorelease the cell first!!
and if filters is not a retain property.. kindly make it one and synthesize it and again if ARC not used then release it in the dealloc block.. that should do it i suppose..