Hello i'm trying to implement NSUserDefaults stream that listens to changes to on a key The code i f...

# kotlin-native

[Ahmed Elkhodery]

Hello i'm trying to implement NSUserDefaults stream that listens to changes to on a key
The code i found is in objc

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSUserDefaults standardUserDefaults] addObserver:self
                                            forKeyPath:@"SomeKey"
                                               options:NSKeyValueObservingOptionNew
                                               context:NULL];
    // Testing...
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 
    [defaults setObject:@"test" forKey:@"SomeKey"];
    [defaults synchronize];
}
- (void)viewDidUnload
{
    [super viewDidUnload];

    [[NSUserDefaults standardUserDefaults] removeObserver:self forKeyPath:@"SomeKey"];
}

- (void)observeValueForKeyPath:(NSString *) keyPath ofObject:(id) object change:(NSDictionary *) change context:(void *) context
{
    if([keyPath isEqual:@"SomeKey"])
    {
       NSLog(@"SomeKey change: %@", change);
    }
}

the interesting part is the self in the addObserver but how to implement that in kotlin native

[Ahmed Elkhodery]

I'm assuming i will create a kotlin class that inherits from NSObject() and have observeValueForKeyPath() method in it but i'm not sure what is this function signature will be

[Jeff Lockhart]

See this thread.

[Ahmed Elkhodery]

thank you for response
Well i've added the observer.def file in src/nativeInterops
and added this part in kotlin block in gradle.build.kts

ios {
        compilations.all {
            cinterops {
                val observer by creating {
                    defFile(project.file("src/nativeInterop/cinterop/observer.def"))
                    packageName("kmp.observer")
                }
            }
        }
    }

but i'm always getting unresolved reference at kmp in import kmp.observer statment

[Ahmed Elkhodery]

Well never mind i was using it i a common sourceset that includes iosSimulator target as well as ios() target, without adding the introp to the iosSimulator() target,
doing so fixed the problem

[Ahmed Elkhodery]

thanks alot