Question

hoping someone can help me.

In the didSelectRowAtIndexPath method, I am loading and pushing detail view controller, when you tap the “back” button in the detail view to go back to the root view, the app will crash. No error logs or anything.

I’m 95% sure it’s got something to do with the “rides” object being released too early, but can’t figure it out.

Thanks for your help!

#import "RidesViewController.h"
#import "RideDetailViewController.h"
#import "JSON.h"

@implementation RidesViewController
@synthesize rides;

#pragma mark -
#pragma mark View lifecycle
- (void)viewDidLoad {

    [super viewDidLoad];

    self.tableView.backgroundView   = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"table-view-background.png"]];

    rides                           = [[NSDictionary alloc] init];

    NSString        *filePath       = [[NSBundle mainBundle] pathForResource:@"rides" ofType:@"JSON"];
    NSData          *jsonData       = [NSData dataWithContentsOfFile:filePath];  
    NSString        *responseString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

    NSDictionary    *results        = [responseString JSONValue];

    rides                           = [results objectForKey:@"rides"];

    [rides retain];
}

#pragma mark -
#pragma mark Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return [rides count];
}

- (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];

    cell.textLabel.text     = [[rides valueForKey:@"title"] objectAtIndex:indexPath.row];
    cell.accessoryType      = UITableViewCellAccessoryDisclosureIndicator;

    return cell;
}

#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    RideDetailViewController *rideDetailViewController = [[RideDetailViewController alloc] initWithNibName:@"RideDetailViewController" bundle:nil];

    NSString        *aTitle         = [[NSString alloc] initWithString:[[rides valueForKey:@"title"] objectAtIndex:indexPath.row]];
    NSString        *aImagePath     = [[NSString alloc] initWithString:[[rides valueForKey:@"imagePath"] objectAtIndex:indexPath.row]];
    NSString        *aDescription   = [[NSString alloc] initWithString:[[rides valueForKey:@"description"] objectAtIndex:indexPath.row]];
    NSString        *aVideoPath     = [[NSString alloc] initWithString:[[rides valueForKey:@"videoPath"] objectAtIndex:indexPath.row]];

    [rideDetailViewController initWithTitle:aTitle imagePath:aImagePath description:aDescription videoPath:aVideoPath];

    [self.navigationController pushViewController:rideDetailViewController animated:YES];

    [rideDetailViewController   release];
    [aTitle                     release];
    [aImagePath                 release];
    [aDescription               release];
    [aVideoPath                 release];
}

#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {

    [super  didReceiveMemoryWarning];
}

- (void)dealloc {
    [super  dealloc];
}


@end

Answer 1

Define your NSString‘s in your header, then place them in cellForRowAtIndexPath: