Room TypeConverter with constructer

Question

I have Room TypeConverter and I need to inject parameter to it\'s constructor

class RoomConverters(moshi Moshi) {

    @TypeConverter
    fun fromUs         


        

Answer 1

I use dagger-android, and faced same problem. Solution is when creating AppDatabase

@Provides @Reusable
fun provideDatabase(context: Context, moshi: Moshi): AppDatabase = 
    Room.databaseBuilder(...).build().apply { AppDatabase.moshi = moshi }

AppDatabase is simple RoomDatabase:

@Database(
    entities = [OrderEntity::class],
    version = 1,
    exportSchema = false
)
@TypeConverters(DbConverters::class)
abstract class AppDatabase : RoomDatabase() {
    companion object {
        lateinit var moshi: Moshi
    }

    abstract fun orderDao(): OrderDao
}

Then use this companion object in converter:

class DbConverters {

    @TypeConverter
    fun orderInfoToString(orderInfo: OrderInfo?): String? = 
           AppDatabase.moshi.adapter(OrderInfo::class.java).toJson(orderInfo)

    @TypeConverter
    fun stringToOrderInfo(value: String): OrderInfo? = 
          AppDatabase.moshi.adapter(OrderInfo::class.java).fromJson(value)
}

This is looking ugly, I guess, but works. Maybe using static/companion object with @Reuseable scope is a bad idea. Moshi, though, is provided using @Singleton scope in AppModule, so basically live through entire application life