Question

I have a login view controller called from a Storyboard segue. When the user logs in correctly, I need to close the current ViewController, return to the caller ViewController and hide the login button.

How can I refer to the sender ViewController, to hide the button? Do I have to pass an instance of the root ViewController to the login or is there another way?

Answer 1

Use delegation.

For your DetaliViewControler create a protocol, like

@protocol DetailViewControllerDelegate <NSObject>
-(void)successFullyLoggedInOnController:(DetailViewController *) controller;
@end

add a delegate declaration to DetailViewController’s interface like

@property (weak) id<DetailViewControllerDelegate> delegate;

Make the MasterViewController conform to the protocol.

-(void)successFullyLoggedInOnController:(DetailViewController *) controller
{
    [self.loginButton setHidden:YES];
}

Now just before the MasterViewController displays the DetailViewController, doe something like

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"DetailViewSegue"]) {
        DetailViewController *vc = segue.destinationViewController;
        vc.delegate = self;
    }
}

In the DetailViewController once the credential where entered and verified call

[self.delegate successFullyLoggedInOnController:self];

and dismiss the DetailViewController