Question

I’m creating a UIPopoverController and setting “Editor1” as the content view controller.
When the caller receives the didDismissPopover I’m releasing the UIPopoverController.
This is the code:

- (IBAction)open1:(id)sender {

Editor1 *editor = [[Editor1 alloc] initWithNibName:@"Editor1" bundle:nil];
_popoverController = [[UIPopoverController alloc] initWithContentViewController:editor];
_popoverController.delegate = self;
[editor release];

[self.popOverController presentPopoverFromRect:self.open1Button.bounds inView:self.open1Button permittedArrowDirections:UIPopoverArrowDirectionAny animated:NO];
}

- (BOOL)popoverControllerShouldDismissPopover:(UIPopoverController *)popoverController{
    NSLog(@"popoverControllerShouldDismissPopover");
    return YES;
}

- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController{
     NSLog(@"popvoerControllerDidDismissPopover");
    [_popoverController release];
}

In my editor I have a UITextField where the user changes text and I save it when I get the message “editingDidEnd”

- (IBAction)editingDidEnd:(id)sender {
   NSLog(@"Editing did End");
   // SAVE PROCEDURE
}

My question regards the order in which the methods get called.
The order is:

2011-09-07 12:35:21.628 iosTest[1967:b603] popoverControllerShouldDismissPopover
2011-09-07 12:35:21.629 iosTest[1967:b603] popvoerControllerDidDismissPopover 
2011-09-07 12:35:21.983 iosTest[1967:b603] Editing did End
2011-09-07 12:35:21.985 iosTest[1967:b603] viewWill Disappear

As you can see the popoverControllerDidDismissPopover gets called before editingDidEnd:, so this means I’m releasing the popover before I do my save procedure. This could bring me a crash problem.

Also, in my save procedure I need to ask the user for confirmation in some cases. I’m using a UIAlertView for this.

Do you have any recommendations?

Answer 1

Usually views are well-behaved and don’t send events after they’re off-screen. You can check for potential problems by enabling zombies (set the environment variable NSZombieEnabled=YES).

If there is a crash, the correct place to fix it is in -[Editor1 dealloc] (and possibly -viewDidUnload): just do textField.delegate = nil and you should stop receiving callbacks. This is not usually necessary except for web views and scroll views where it seems to be problematic (the scroll animation continues even if the VC is off-screen).

In your case, you can probably make saving happen in -popoverControllerShouldDismissPopover:, returning NO if you need to display a UIAlertView (and dismissing the popover when the button is pressed).