trying to update a UILabel on a parent view controller when dismissing the modal view

Question

I am trying to update a UILabel in a parent View after someone makes a change in a modal view. So, after they click \"save\" ... the newly entered value would change what t

Answer 1

To elaborate on my comment. This is how I would implement a delegation method to update the label.

In the header of the parent view controller:

#import "ModalViewController.h"

@interface ViewController : UIViewController 

/* This presents the modal view controller */
- (IBAction)buttonModalPressed:(id)sender;

@end

And in the implementation:

/* Modal view controller did save */
- (void)modalViewControllerDidSave:(ModalViewController *)viewController withText:(NSString *)text
{
    NSLog(@"Update label: %@", text);
}

/* Prepare for segue */
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"modalSegue"])
    {
        ModalViewController *mvc = (ModalViewController *) segue.destinationViewController;
        mvc.delegate = self;
    }
}

/* Present modal view */
- (IBAction)buttonModalPressed:(id)sender
{
    [self performSegueWithIdentifier:@"modalSegue" sender:self];
}

Here you see the delegation method in the top.

The header of the modal view controller would contain the delegation protocol like this:

@protocol ModalViewControllerDelegate;

@interface ModalViewController : UIViewController

@property (nonatomic, weak) id  delegate;

- (IBAction)buttonSavePressed:(id)sender;

@end

@protocol ModalViewControllerDelegate 
- (void)modalViewControllerDidSave:(ModalViewController *)viewController withText:(NSString *)text;
@end

The implementation of the modal view controller would contain a method similar to this one:

/* Save button was pressed */
- (IBAction)buttonSavePressed:(id)sender
{
    if ([self.delegate respondsToSelector:@selector(modalViewControllerDidSave:withText:)])
        [self.delegate modalViewControllerDidSave:self withText:@"Some text"];

    [self dismissModalViewControllerAnimated:YES];
}

When the save button is pressed, the delegate is notified and the text in your text view is sent through the delegation method.