Question

I am creating a split-view iPad application. When the user presses the bar button item in the master view, a modal is presented. This modal has a textfield and has an IBAction to pick up keyboard returns.

On keyboard returns, a new instance of my Farm class is created (code below). This instance is then added to an array that is stored in my delegate. I then try to reload the MasterViewController‘s table. Upon this reload the application crashes on cell.textLabel.text with a EXC_BAD_ACCESS error.

Farm *current = [delegate.arrayOfFarms objectAtIndex:indexPath.row];
cell.textLabel.text = [current getFarmTitle];

If I ask the array within the delegate how many elements it has, it will indeed show the current amount, even. This is what is bizarre to me about this whole thing: the Farm instances appear to be in existence.

I have instances of AppDelegate in both my MasterViewController and my NewFarmNamingView classes. The instance in the Master is to populate the table. The instance in NewFarm is to add the newly created Farm to the delegate. Code below.

Segments from class NewFarmNamingView:

- (IBAction) keyboardDonePushed:(id)sender
{
    // create a Farm and add it to the delegate
    NSString *text = newFarmTextField.text;
    Farm *newFarm = [[Farm alloc] init];
    [newFarm setFarmTitle:text];
    [[delegate arrayOfFarms] addObject:newFarm];
    [newFarm release];

    NSLog(@"Added farm: %@" , text);

    // dismiss the view
    [self closeView:nil];
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // initialize the delegate
    delegate = [[UIApplication sharedApplication] delegate];
}

Segments from the class Farm

- (void) setFarmTitle : (NSString *) _farmTitle
{
    farmTitle = _farmTitle;
}

- (NSString *) getFarmTitle
{
    return farmTitle;
}

// NSCoding Methods
- (void) encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:farmTitle forKey:@"kFarmTitle"];
}

- (id) initWithCoder:(NSCoder *)aDecoder
{
    farmTitle = [aDecoder decodeObjectForKey:@"kFarmTitle"];
    return self;
}

// Initialization method
- (id)init
{
    self = [super init];
    if (self) {
        // Initialization code here.
    }

    return self;
}

Answer 1

From the runtime reference: “objc_msgsend sends a message to the receiver and expects a simple return value.”

I’ll bet you anything that what you’re returning (if you’re returning anything at all) in that class method getTitleFarm is returning an incorrect value. It should be an NSString. Be absolutely sure it is returning an NSString, and not anything else.

If you need to use the respondsToSelector method to see if the class is being released, try:

if([current respondsToSelector:@selector(getFarmTitles)])  {.    [current getFarmTitle];
} 
else {
NSLog:(@"FAILURE!!");
}

EDIT: maybe you are not retaining or even creating this string at all. In it’s initialization, wrap it in a retain]; message