OS X Delegate set label from other window (Xcode) - objective-c

Question

I'm quite new to Mac programming (not to Objective C).
I'm developing a small application, that shows some data and opens a second window on button press.
In the second window is a textfield and a submit button. If the submit button is pressed, the window should close + the value of the textfield needs to be passed to the first window.
I think the best method for that is a simple Delegate. I tried that but i can't change the label in the first window using the second window..
The delegate however seems to work as i can call methods from the other class and send data to it. It just won't change the label.
As this is my first try on Delegates, im pretty sure I've done something stupid here^^
or is there a better solution? Can't be to complicated to change a label from an second window.. right?
ViewController.h (FirstController)
#import <Cocoa/Cocoa.h>
#class ViewController;
#protocol ViewControllerDelegate
-(void)sayHello:(ViewController *)ViewController;
#end
#interface ViewController : NSViewController
{
IBOutlet NSTextField *txtlabel;
}
#property (nonatomic, assign) id delegate;
-(void)helloDelegate;
-(void)reciveVar:(NSString*)strvar;
#end
ViewController.m (FirstController)
#import "ViewController.h"
#implementation ViewController
#synthesize delegate;
-(id)init {
self = [super init];
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
txtlabel.stringValue=#"TEST";
}
-(void)helloDelegate
{
[delegate sayHello:self];
}
-(void)reciveVar:(NSString*)strvar
{
NSLog(#"recived: %#", strvar);
txtlabel.stringValue=strvar; // DOSENT WORK!!
}
#end
secondController.h
#import <Cocoa/Cocoa.h>
#import "ViewController.h"
#interface secondController : NSViewController <ViewControllerDelegate>
{
IBOutlet NSTextField *txtfield;
}
-(IBAction)submit:(id)sender;
#end
secondController.m
#import "firstController.h"
#implementation secondController
-(void)viewDidLoad
{
[super viewDidLoad];
ViewController *custom = [[ViewController alloc] init];
// assign delegate
custom.delegate = self;
[custom helloDelegate];
}
-(void)sayHello:(ViewController *)ViewController
{
NSLog(#"Hiya!");
}
-(IBAction)submit:(id)sender
{
NSString *txtval= txtfield.stringValue;
NSLog(#"submit: %#", txtval);
ViewController *custom = [[ViewController alloc] init];
// assign delegate
custom.delegate = self;
[custom reciveVar:txtval];
}
#end
LOG Output:
Hiya!
submit: test
recived: test
(so i guess the delegate works..)

Answer 1

SOLVED. (Thanks to Phillip Mills)
NSNotification is way simpler and efficient than Delegates in this case.
ViewController.m
[...]
- (void)viewDidLoad
{
[super viewDidLoad];
txtlabel.stringValue=#"TEST";
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(handleUpdatedData:)
name:#"DataUpdated"
object:nil];
}
-(void)handleUpdatedData:(NSNotification *)notification
{
NSLog(#"recieved %#", notification);
txtlabel.stringValue=[notification object];
}
secondController.m
-(IBAction)submit:(id)sender
{
NSString *txtval= txtfield.stringValue;
NSLog(#"submit: %#", txtval);
[[NSNotificationCenter defaultCenter] postNotificationName:#"DataUpdated"
object:txtval];
}