Android Safe Args crashing

Question

So I'm trying to navigate to a Fragment with a deep link, and I keep crashing.

java.lang.UnsupportedOperationException: Parcelables don't support default values.

Here's the fragment in NavGraph

<fragment
    android:id="@+id/appsAndDevicesFragment"
    android:name="life.[REDACTED].wearable.wearablesettings.AppsAndDevicesFragment">
    <argument
        android:name="selectedDevice"
        app:argType="string"
        app:nullable="true" />

    <argument
        android:name="requiredDataPointsString"
        app:argType="string"
        android:defaultValue="@null"
        app:nullable="true"/>

    <argument
        android:name="dataPoint"
        android:defaultValue="@null"
        app:argType="life.[REDACTED].wearable.model.WearableDataType"
        app:nullable="true" />

    <deepLink
        android:id="@+id/deepLink9"
        app:uri=".*/member/health/apps-and-devices?data_point={dataPoint}" />
    <deepLink
        android:id="@+id/deepLink11"
        app:uri=".*/member/health/apps-and-devices?required_data_points_string={requiredDataPointsString}" />

Link code

(activity as? RootActivity)?.navigateToDeeplink(
            url = WearableDeepLinker.WearablePaths.AppsAndDevices.construct(null),
            openBrowserIfUnsupported = false,
            setRootNavigation = false,
            navController = findNavControllerSafely()
        )

Here's the enum

@Parcelize
enum class WearableDataType(val value: String): Serializable, Parcelable  {
    @Json(name ="steps") STEPS("steps"),
    @Json(name ="active_duration") ACTIVE_DURATION("active_duration"),
    @Json(name ="mindful_duration") MINDFUL_DURATION("mindful_duration"),
    @Json(name ="floors_climbed") FLOORS_CLIMBED("floors_climbed"),
    @Json(name ="sleep_duration") SLEEP_DURATION("sleep_duration");
}

I'm not entirely sure what it means by default value, what default?

I've also tried wraping this in a data class but still get the same error

Answer 1

<argument
    android:name="dataPoint"
    android:defaultValue="@null"
    app:argType="life.[REDACTED].wearable.model.WearableDataType"
    app:nullable="true" />

Change it to string type.

<argument
    android:name="dataPoint"
    android:defaultValue="@null"
    app:argType="string"
    app:nullable="true" />

Also, if it is kotlin code. WearableDataType can't have null value as parameter.