Calling a Function in MasterView after dismissing the ModalView in ipad - ios

Question

I am using Master-Detail template for ipad. I have a ViewController, which I want to show modally so I have used this code
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
m_ViewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
m_ViewController.modalPresentationStyle = UIModalPresentationFormSheet;
[appDelegate.splitViewController presentModalViewController:m_ViewController animated:YES];
This works fine and the ViewController is loaded modally, Now I tried to dismiss this ViewController, So inside ViewController.m, I called this line of code
[self dismissModalViewControllerAnimated:YES];
This code also works fine and the ViewController gets dismissed, But after dismissing I want to call a function in my MasterView. How to do that?
Code added according to the discussion with Moxy.
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.testViewController testfunction:testImage];

Answer 1

As amit3117 pointed out, you should use a delegate.
The protocol should be defined at least with a method that would communicate to the delegate that the view controller that was presented modally did finish its work.
#class ViewController;
#protocol MyViewControllerDelegate <NSObject>
-(void)viewControllerDidFinish:(ViewController *)sender;
#end
EDIT : I forgot to add that you should a public property for the delegate to ViewController
#interface ViewController : UIViewController
#property (nonatomic, weak) id <MyViewControllerDelegate> delegate;
#end
You could use your master view controller as the delegate. So in your master view controller implementation you would also have :
#interface MyMasterViewController () <MyViewControllerDelegate>
#end
#implementation MyMasterViewController
-(void)showViewController
{
m_ViewController = [[ViewController alloc] initWithNibName:#"ViewController"
bundle:nil];
m_ViewController.modalPresentationStyle = UIModalPresentationFormSheet;
m_ViewController.delegate = self;
// –presentModalViewController:animated: is deprecated!
[self.parentViewController presentViewController:m_ViewController
animated:YES
completion:nil];
}
-(void)viewControllerDidFinish:(ViewController *)sender
{
// Add any code you want to execute before dismissing the modal view controller
// –dismissModalViewController:animated: is deprecated!
[self.parentViewController dismissViewControllerAnimated:YES
completion:^{
// code you want to execute after dismissing the modal view controller
}];
}
#end
When m_ViewController finishes its work, it should call :
[self.delegate viewControllerDidFinish:self];