Android Databinding error in compilation with nullable parcelable argument

Question

I want to pass a Parcelable class Payment, that I created, from one fragment to another with safe args, but it can be null.

I created the argument of type com.example.Payment and make it nullable. When I compile the app I get an error saying Expression in a class literal has a nullable type 'Payment?', use !! to make the type non-nullable in FragmentDirection, under the build folder.

The error happended in this line :

@Suppress("CAST_NEVER_SUCCEEDS")
class FragmentDirections private constructor(
 {    
   private data class GoToNew(
       val Payment: Payment?
     ) : NavDirections {

      override fun getArguments(): Bundle {
         val result = Bundle()
         if (Parcelable::class.java.isAssignableFrom(Payment::class.java)) { // Error happend here, when trying to get the class of Payment
           result.putParcelable("Payment", this.Payment as Parcelable?)
         } else if (Serializable::class.java.isAssignableFrom(Payment::class.java)) { // There is also the same error here
           result.putSerializable("Payment", this.Payment as Serializable?)
         } else {
           throw UnsupportedOperationException(Payment::class.java.name +
               " must implement Parcelable or Serializable or must be an Enum.") // and here
         }
         return result
       }
//...
}

I don't know what I did wrong and can't edit the file because its under build folder.

EDIT : There is the xml code of the navigation :

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_navigation"
    app:startDestination="@id/listFragment">
    <fragment
        android:id="@+id/newPaymentFragment"
        android:name="com.example.wallet.application.newPayment.NewPaymentFragment"
        android:label="fragment_new_payment"
        tools:layout="@layout/fragment_new_payment" >
        <argument android:name="Payment"
            app:argType="com.example.Payment"
            app:nullable="true"/>
        <action
            android:id="@+id/backToList"
            app:destination="@id/listFragment" />
        <action
            android:id="@+id/goToDetail"
            app:destination="@id/detailFragment" />
    </fragment>
    <!-- ... -->

</navigation>

Answer 1

In module level gradle file change apply plugin: "androidx.navigation.safeargs.kotlin" to apply plugin: "androidx.navigation.safeargs". I have tried this one and its working fine now.

Answer 2

Change Your <argument android:name="Payment"> To <argument android:name="payment"