Question

I am using a navigation based iPhone application, and I defined an IBOutlet propert in the inner view and synthesized it,

The issue is when I want to set the IBOutlet value before pushing the new view controller, the value won’t be set. Here is a snippet from the code:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

    MealDetailViewController *mealViewController = [[MealDetailViewController alloc] initWithNibName:@"MealDetailViewController" bundle:nil];

    MealsModel *model = (MealsModel *)[_items objectAtIndex:indexPath.row];

    NSLog(model.Name);// here it writes the name right as a string

    //mealViewController.lblName.text=model.Name;

    [[mealViewController lblName]setText:model.Name];
    [[mealViewController txtDesc]setText:model.Description];

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

    [mealViewController release];
}

I didn’t face like these issues in the previous versions of Xcode.

Answer 1

It’s to do with when your view controller’s views are being created.

When you do

[[mealViewController lblName] setText:model.Name];

you haven’t loaded it’s view yet so lblName will be nil.

Try either

(a) Explicitly asking for the view, triggering the subviews to be created :

[mealViewcontroller view];
[[mealViewController lblName]setText:model.Name];
[[mealViewController txtDesc]setText:model.Description];

or

(b) Letting the navigation controller create the views for you

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

[[mealViewController lblName]setText:model.Name];
[[mealViewController txtDesc]setText:model.Description];

or

(c) Store the values in the mealViewController as properties

MealViewController.h

@property (nonatomic, copy) NSString *lblNameString;
@property (nonatomic, copy) NSString *txtDescString;

MealViewcontroller.m

@synthesize txtDescString, lblNameString;

and instead of setting the label directly, set the properties instead.

[mealViewController setLblNameString:model.Name];
[mealViewController setTxtDescString:model.Description];

Then, in your newWillAppear, setting them

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    lblName.text = lblNameString;
    txtDesc.text = txtDescString;
}

(c) is the more correct way to do it – (a) and (b) both fail if your view controller’s view is unloaded by a low memory warning.