Safe Args: use list of parcelables

Question

I am using the Safe Args plugin with the new Navigation components for my Android project. Now I have an argument that is an array list of parcelables, is there a way to use this with the Safe Args Plugin?

Something like app:argType=ParcelableArray. This should be possible since there are bundle methods like putParcelableArrayList().

Answer 1

Currently i don't think there is a simple way to use list of parcelables with safe args, But i have found some "hack" to make this work. For example, i have object 'User' and it parcelable, i am declaring a new parcelable object 'Users' that extending ArrayList().

@Parcelize
data class User(var name: String, val age: Int): Parcelable

@Parcelize
class Users: ArrayList<User>(), Parcelable

Now i can set 'Users' as argument in navigation

<argument
      android:name="users"
      app:argType="com.navigation.test.Users"/>

And passing array list of parcelables between destinations:

 val user=User("Alex", 36)
 val users= Users()
 users.add(user)
 val action=MainFragmentDirections.actionMainFragmentToSecondFragment(users)
 NavHostFragment.findNavController(this@MainFragment).navigate(action)

And to retrieve them on other destination:

val users=SecondFragmentArgs.fromBundle(arguments).users
val user=users[0]
txtViewName.text=user.name
txtViewAge.text="${user.age}"

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Update:

Support to list of objects coming in alpha8: https://issuetracker.google.com/issues/111487504

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Update 2: The approach mentioned above will not work in case the activity is recreated, as @Parcelize will not be able to store/restore the list.

The object will be store in the state bundle, however, it will store an empty list of objects.