Android Parcelable in Kotlin: CREATOR not found on Parcelable data class

Question

With the release of the Kotlin RC, I started writing an app to learn it however I can not figure out how to get Parcelable to work.

the data class:

data class Project (val reponame:String,
                val username:String,
                val language:String,
                val vcsUrl:String,
                val branches:Map<String, Branch>) : Parcelable {

    companion object {
        val CREATOR = object : Parcelable.Creator<Project> {
            override fun createFromParcel(`in`: Parcel): Project {
                return Project(`in`)
            }

            override fun newArray(size: Int): Array<Project?> {
                return arrayOfNulls(size)
            }
        }
    }

    protected constructor(parcelIn: Parcel) : this (
            parcelIn.readString(),
            parcelIn.readString(),
            parcelIn.readString(),
            parcelIn.readString(),
            mapOf<String, Branch>().apply {
                parcelIn.readMap(this, Branch::class.java.classLoader)
            }
    )

    override fun describeContents(): Int {
        throw UnsupportedOperationException()
    }

    override fun writeToParcel(dest: Parcel, flags: Int) {
        dest.writeString(reponame)
        dest.writeString(username)
        dest.writeString(language)
        dest.writeString(vcsUrl)
        dest.writeMap(branches)
    }

}

Reading it:

class ProjectDetailActivity : BaseActivity() {

    lateinit var project: Project

    companion object {
        const val EXTRA_PROJECT = "extra_project"
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        project = intent.extras.getParcelable(EXTRA_PROJECT)

        tvTitle.text = project.reponame
    }
}

The exception:

Caused by: android.os.BadParcelableException: Parcelable protocol requires a Parcelable.Creator object called CREATOR on class com.eggman.circleciandroid.model.Project
    at android.os.Parcel.readParcelableCreator(Parcel.java:2415)
    at android.os.Parcel.readParcelable(Parcel.java:2337)
    at android.os.Parcel.readValue(Parcel.java:2243)
    at android.os.Parcel.readArrayMapInternal(Parcel.java:2592)
    at android.os.BaseBundle.unparcel(BaseBundle.java:221)
    at android.os.BaseBundle.get(BaseBundle.java:281)
    at com.eggman.circleciandroid.ui.ProjectDetailActivity.onCreate(ProjectDetailActivity.kt:22)

I am sure it is something simple I am missing, has anyone else had success with Parcelable on latest Kotlin?

Kotlin Version: 1.0.0-rc-1036

Kotlin Plugin Version: 1.0.0-rc-1036-IJ143-4

Code is viewable @ https://github.com/eggman87/circle-kotlin

Answer 1

Kotlin RC dropped previously deprecated generation of static fields for all companion object properties (learn more in this answer).

Now only those marked by const, lateinit or @JvmField will have a static field generated.

You need to annotate val CREATOR by @JvmField annotation since Android Framework expects a static field CREATOR in your class.

Answer 2

Here you have some useful Kotlin extension functions that will help you to create your CREATORs and also some examples (using data classes and list inside the data class)

Gist: Data Class & Parcelables example

I'm using this code in an Android App: (link)

The same code you can find it here: (link)