Making sealed class hierarchy Parcelable

Question

I have something similar like the following where I want to pass them around as intent arguments;

sealed class BasketType : Parcelable {

    class BasketOne(val basketId: String): BasketType() {

        constructor(parcel: Parcel) : this(parcel.readString()) {
        }

        override fun writeToParcel(parcel: Parcel, flags: Int) {
            super.writeToParcel(parcel, flags)
            parcel.writeString(basketId)
        }

        override fun describeContents(): Int {
            return 0
        }

        ...
    }

    ...
}

But I get the following error;

Abstract member cannot be accessed directly

on the line super.writeToParcel(parcel, flags) which is kind of expected.

I've looked around for a workaround but could not find one. Any ideas?

score 72 · Answer 1 · edited Oct 12 '21 at 13:43

72

if you want @Parcelize in sealed class, do it like this:

sealed class AssistantType : Parcelable{
    @Parcelize data class Dashboard(
        val firstName: String,
        val hasGoal: Boolean,
        val hasOverDuePayment: Boolean
    ) : AssistantType()

    @Parcelize data class Detail(
        val firstName: String,
        val isGoalAchived: Boolean
    ) : AssistantType()
}

and Add below code into your App Level gradle.

apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

androidExtensions {
    experimental = true
}

edited Oct 12 '21 at 13:43

Boken

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answered Sep 15 '20 at 16:43

Adnan Abdollah Zaki

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1

Thanks @Adnan, I went nuts trying to add `@Parcelize` to the class itself. That code made the trick. – GoRoS Jan 27 '22 at 19:34
1

Hi. Is that extension in Gradle required or can be ignored? Thanks – Mark Delphi Dec 03 '22 at 09:42

score 3 · Accepted Answer · answered Sep 05 '19 at 17:18

You simply leave out the super call. There is no super implementation of that function, which is why it's complaining.

override fun writeToParcel(parcel: Parcel, flags: Int) {
    parcel.writeString(basketId)
}

the super call is only there because the code generation of android studio puts it there without checking that it's actually possible.

Making sealed class hierarchy Parcelable

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