I want to hide my bottom nav on certain screens. R...

# compose

[Florian]

I want to hide my bottom nav on certain screens. Right now I'm using the route to compare destinations. This doesn't work with optional arguments anymore, because the route property of the `navBackStackEntry`'s destination contains the argument syntax. But in order to add arguments later, my own route string needs to be the "base" route without arguments.

val navBackStackEntry by navController.currentBackStackEntryAsState()
val currentDestination = navBackStackEntry?.destination
val hideBottomNav = fullScreenDestinations.any { destination ->
    destination.route == currentDestination?.route
}

So here destination.route = "AddEditTask" while currentDestination.route = "AddEditTask?taskId=taskID".

How else could I check what destination we are currently on?
using contains to compare a sub-string seems error-prone.

[Ian Lake]

Is there a reason you went with a route based approach rather than an argument based approach? https://kotlinlang.slack.com/archives/CJLTWPH7S/p1627955172336400?thread_ts=1627937745.328400&cid=CJLTWPH7S

[Florian]

I followed the instructions for nav arguments with Compose

[Florian]

your link leads me to XML code

[Florian]

ah now I realize that you are not referring to the way I pass arguments, but to the way I check for full-screen destinations

[Florian]

I'll try to implement that, thank you!

[Florian]

@Ian Lake Like this?

composable(
            route = BottomNavDestination.Timer.route,
            arguments = listOf(
                navArgument(ARG_SHOW_BOTTOM_NAV) {
                    type = NavType.BoolType
                    defaultValue = true
                }
            )
        ) {
            TimerScreen()
        }

Scaffold(
        bottomBar = {
            val navBackStackEntry by navController.currentBackStackEntryAsState()
            val currentDestination = navBackStackEntry?.destination
            val showBottomNav = navBackStackEntry?.arguments?.get(ARG_SHOW_BOTTOM_NAV) == true

[...]

[Ian Lake]

Yep. Although you should be able to drop the explicit BoolType - it should be automatically determined from the default value

[Florian]

Cool, didn't know that! Thank you very much!