Parceler: Unable to find read/write generator for type MutableLiveData<User> in Android ViewModel

Question

I'm getting a compilation build error when I add a MutableLiveData object to my view model in my Android Studio project. I'm not calling getUser() or setUser() anywhere yet and I added the exact same object to a different view model in my project and haven't gotten an error, so I'm not sure what the problem is.

Error: error: Parceler: Unable to find read/write generator for type androidx.lifecycle.MutableLiveData<com.example.demometvtest1.User> for com.example.demometvtest1.RegisterViewModel.user

RegisterViewModel.java:

import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;

@Parcel
public class RegisterViewModel extends ViewModel {
    public MutableLiveData<User> user = new MutableLiveData<>();

    public void setUser(String user) {
        return user;
    }

    public MutableLiveData<User> getUser() {
        this.user.setValue(user);
    }
}

Answer 1

The problem is the annotation @Parcel: you are trying to automatic generate writeToParcel() & createFromParcel() and the annotation processor doesn't find a read/write implementation for MutabileLiveData (that it's not parcelable). Remove the annotation, make the class implement the parcelable interface and make your own implementation of parcelable metods writeToParcel() & createFromParcel() if you need It or simply remove the annotation.