Question

I am in a viewController, lets call it vcA and I call a second one vcB, using

[self presentModalViewController:vcB animated:YES];

once vcB is loaded is there any way to obtain a reference to vcA?

Yes, I know that I can subclass vcB and add a property to it. I am just asking if there is some native iOS method/property/whatever that already does that.

I am on a navigationController app.

Thanks.

Answer 1

If it’s for single fire use and there is not a lot of collaboration I tend to prefer blocks over delegation as it’s seems a bit tidier.

For example if it was just to call back when you have finished using the secondViewController I would:

Add a block property to the SecondViewController

@property (nonatomic, strong) void (^onCompletion)(void);

Then in the firstViewController when you create the secondViewController

- (void)showSecondViewController;
{
  SecondViewController *viewController = [[SecondViewController alloc] init];
  viewController.onCompletion = ^{
    [self dismissViewControllerAnimated:YES completion:nil];
  };

  [self presentViewController:viewController
                 animated:YES
               completion:nil];
}

Then in the secondViewController when you are finished

- (IBAction)doneTapped;
{
  if (self.onCompletion) {
    self.onCompletion();
  }
}

If you need a return value then just modify the block to accept an argument