Automatic Marshal creation from an existing entity

I normally create database records by converting an AutoParcel entity into ContentValues. It would be nice to have Marshal class have a constructor that accepts an entity as a single argument. Or this could probably be solved by adding toContentValues method to Mapper.

Overall I feel like existing Marshal class is a complication, we already have builder pattern from AutoParcel, so it does not add much. We can make id nullable somehow so we will avoid the case when we can’t pass AutoParcel nullability issue with an id that does not exist yet.

[PaulWoitaschek]

Thanks for the hint! I ended with just each class having a method called contentValues() handling that so it stays an implementation detail.

That has the convenience of being very scoped.

@AutoValue public abstract class TrackInfo implements TrackInfoModel {

   // ...

   public static final Mapper<TrackInfo> MAPPER = new Mapper<>(AutoValue_TrackInfo::new);

   public ContentValues contentValues(long showId) {
      ContentValues cv = new TrackInfoMarshal<>(this).asContentValues();
      cv.remove(_ID);
      cv.put(SHOWID, showId);
      return cv;
   }
}

[AlecStrong]

you can create your own constructor which ignores the id

public class User implements UserModel {
  public class Marshal extends UserMarshal<Marshal> {
    public Marshal(User user) {
      super(user);
      contentValues.remove(USER_ID);
    }
  }
}