Alpakka MongoDB - override MongoSource implementation

Question

I have similar problem as in Alpakka MongoDB - specify type in MongoSource

So I implemented my own MongoSource as was in the solution and used it:

object MyMongoSource {
  def apply[T](query: Observable[T]): Source[T, NotUsed] =
    Source.fromPublisher(ObservableToPublisher(query))
}

val source: Source[Book, NotUsed] = MyMongoSource[Book](mongoDb.books.find()) 

But ObservableToPublisher is private class so I get the following error:

object ObservableToPublisher in package mongodb cannot be accessed in package akka.stream.alpakka.mongodb

How to resolve this?

Answer 1

Define MyMongoSource to be in the akka.stream.alpakka.mongodb.scaladsl package:

package akka.stream.alpakka.mongodb.scaladsl

import akka.NotUsed
import akka.stream.alpakka.mongodb.ObservableToPublisher
import akka.stream.scaladsl.Source
import org.mongodb.scala.Observable

object MyMongoSource {
  def apply[T](query: Observable[T]): Source[T, NotUsed] =
    Source.fromPublisher(ObservableToPublisher(query))
}