Pass Parcelable argument with compose navigation

Warning:
Ian Lake is an Android Developer Advocate and he says in this answer that pass complex data structures is an anti-pattern (referring the documentation). He works on this library, so he has authority on this. Use the approach below by your own.

Edit: Updated to Compose Navigation 2.4.0-beta07

Seems like previous solution is not supported anymore. Now you need to create a custom NavType.

Let’s say you have a class like:

@Parcelize
data class Device(val id: String, val name: String) : Parcelable

Then you need to define a NavType

class AssetParamType : NavType<Device>(isNullableAllowed = false) {
    override fun get(bundle: Bundle, key: String): Device? {
        return bundle.getParcelable(key)
    }

    override fun parseValue(value: String): Device {
        return Gson().fromJson(value, Device::class.java)
    }

    override fun put(bundle: Bundle, key: String, value: Device) {
        bundle.putParcelable(key, value)
    }
}

Notice that I’m using Gson to convert the object to a JSON string. But you can use the conversor that you prefer…

Then declare your composable like this:

NavHost(...) {
    composable("home") {
        Home(
            onClick = {
                 val device = Device("1", "My device")
                 val json = Uri.encode(Gson().toJson(device))
                 navController.navigate("details/$json")
            }
        )
    }
    composable(
        "details/{device}",
        arguments = listOf(
            navArgument("device") {
                type = AssetParamType()
            }
        )
    ) {
        val device = it.arguments?.getParcelable<Device>("device")
        Details(device)
    }
}

Original answer

Basically you can do the following:

// In the source screen...
navController.currentBackStackEntry?.arguments = 
    Bundle().apply {
        putParcelable("bt_device", device)
    }
navController.navigate("deviceDetails")

And in the details screen…

val device = navController.previousBackStackEntry
    ?.arguments?.getParcelable<BluetoothDevice>("bt_device")