Android putting parcelable in bundle raises type mismatch

Question

I am trying to put a parcelable in a bundle that I want to send to a navigation component. My data class is,

import android.os.Parcelable
import kotlinx.parcelize.Parcelize

@Parcelize
data class Post(
    val name: String,

    val slug: String,

    val thumbnail:String
) : Parcelable

navigation

<argument
    android:name="post"
    app:argType="com.example.blog.models.Post"
    app:nullable="true" />

viewmodel variable

val post: MutableLiveData<List<Post>> by lazy { MutableLiveData<List<Post>>() }

// after api call, the body of the response which is a list of Post objects
// are attached to viewmodel.

post.postValue(response.body())

fragment

// after observing the changes in the post variable in viewmodel,
// a bundle is created which is added to the navigation.. 

val bundle =  Bundle()
bundle.putParcelable("post", post.value)

errors

Editor

Type mismatch.
Required: Parcelable?
Found: List<Post>?

Build

Type mismatch: inferred type is List<Post>? but Parcelable? was expected

Answer 1

Firs of all you need to use LiveData which will wrap your MutableLiveData.

 fun getPosts(): LiveData<List<Post>> {
        return post
    }

What you want to pass to your Bundle is the List directly, but wrapped in a Serialized implementation of List. That's why the code below wraps the value of your LiveData in an ArrayList.

So, you can do this instead:

  bundle.putParcelableArrayList("post", arrayListOf(getPosts().value));

To read it back:

bundle.getParcelableArrayList("post") as List<Post>?