Navigate between screens with Compose: Android Basics with Compose

[buboj]

URL of codelab
https://developer.android.com/codelabs/basic-android-kotlin-compose-navigation?continue=https%3A%2F%2Fdeveloper.android.com%2Fcourses%2Fpathways%2Fandroid-basics-compose-unit-4-pathway-2%23codelab-https%3A%2F%2Fdeveloper.android.com%2Fcodelabs%2Fbasic-android-kotlin-compose-navigation#4

In which task and step of the codelab can this issue be found?
Navigate between screens with Compose

Describe the problem
Navigation does not work with the provided code for the call of passed functions without parameters () -> Unit

Steps to reproduce?
The tutorial tells me to add this code on onClick of the the button in SelectOptionScreen.kt:

...
Button(
    modifier = Modifier.weight(1f),
    enabled = selectedValue.isNotEmpty(),
    onClick = onNextButtonClicked
) {
    Text(stringResource(R.string.next))
}
...

But this is not working, at least on my setup. I know, that kotlin generally allows function calls without empty parenthesis if there are no parameters needed. But it seems to need empty parenthesis here.
Because if I add them here:
onClick = onNextButtonClicked()
it works like it should!
It took me hours to spot this. Even Gemini did not spot this error, neither did the compiler.

Versions
Android Studio version:
Build #AI-251.25410.109.2511.13752376
API version of the emulator:
API 36

Additional information
Include screenshots if they would be useful in clarifying the problem.

[aaimran236]

@composable
fun SelectOptionScreen(
subtotal: String,
options: List,
onSelectionChanged: (String) -> Unit = {},
onCancelButtonClicked : () -> Unit={},
onNextButtonClicked: () -> Unit={},
modifier: Modifier = Modifier
) {
var selectedValue by rememberSaveable { mutableStateOf("") }

Column(
    modifier = modifier,
    verticalArrangement = Arrangement.SpaceBetween
) {
    Column(modifier = Modifier.padding(dimensionResource(R.dimen.padding_medium))) {
        options.forEach { item ->
            Row(
                modifier = Modifier.selectable(
                    selected = selectedValue == item,
                    onClick = {
                        selectedValue = item
                        onSelectionChanged(item)
                    }
                ),
                verticalAlignment = Alignment.CenterVertically
            ) {
                RadioButton(
                    selected = selectedValue == item,
                    onClick = {
                        selectedValue = item
                        onSelectionChanged(item)
                    }
                )
                Text(item)
            }
        }
        Divider(
            thickness = dimensionResource(R.dimen.thickness_divider),
            modifier = Modifier.padding(bottom = dimensionResource(R.dimen.padding_medium))
        )
        FormattedPriceLabel(
            subtotal = subtotal,
            modifier = Modifier
                .align(Alignment.End)
                .padding(
                    top = dimensionResource(R.dimen.padding_medium),
                    bottom = dimensionResource(R.dimen.padding_medium)
                )
        )
    }
    Row(
        modifier = Modifier
            .fillMaxWidth()
            .padding(dimensionResource(R.dimen.padding_medium)),
        horizontalArrangement = Arrangement.spacedBy(dimensionResource(R.dimen.padding_medium)),
        verticalAlignment = Alignment.Bottom
    ) {
        OutlinedButton(
            modifier = Modifier.weight(1f),
            onClick = onCancelButtonClicked
        ) {
            Text(stringResource(R.string.cancel))
        }
        Button(
            modifier = Modifier.weight(1f),
            // the button is enabled when the user makes a selection
            enabled = selectedValue.isNotEmpty(),
            onClick = onNextButtonClicked
        ) {
            Text(stringResource(R.string.next))
        }
    }
}

}

here is the full SelectOptionScreen class file

onNextButtonClicked is a variable of function type ( ()-> Unit ) so you can call it like any other function (like this onNextButtonClicked() ) but can also assign its value to other variables like any other type

if you defined onNextButtonClicked varible properly, onClick = onNextButtonClicked will work properly