Recipie-Book/app/controllers/MongoDB.scala

package controllers

import org.mongodb.scala.{MongoClient,MongoDatabase};
import org.mongodb.scala.bson.codecs.Macros._
import org.mongodb.scala.bson.codecs.DEFAULT_CODEC_REGISTRY;
import org.bson.codecs.configuration.CodecRegistries.{fromRegistries, fromProviders, fromCodecs}
import org.bson.codecs.{Codec,DecoderContext,EncoderContext}
import org.bson.types.ObjectId
import org.bson.{BsonWriter,BsonReader}
import models._

object MongoDB {
  private def encoderCodec[T](cls: Class[T]): Codec[T] = new Codec[T] {
    def decode(reader: BsonReader, decoderContext: DecoderContext): T = throw new UnsupportedOperationException()
    def encode(writer: BsonWriter, value: T, encoderContext: EncoderContext) = writer.writeString(cls.getSimpleName)
    def getEncoderClass(): Class[T] = cls
  }

  val codecRegistry = fromRegistries(
    fromProviders(classOf[Food]),
    fromCodecs(encoderCodec[Mass](classOf[Mass]),
      encoderCodec[Volume](classOf[Volume]),
      encoderCodec[Number](classOf[Number]),
      new Codec[Measure] {
        def decode(reader: BsonReader, decoderContext: DecoderContext): Measure =
          reader.readString() match {
            case "Mass" => Mass()
            case "Volume" => Volume()
            case "Number" => Number()
            case other: String => throw new RuntimeException(s"Did not recognize measure string: $other")
          }
        def encode(writer: BsonWriter, value: Measure, encoderContext: EncoderContext) = throw new UnsupportedOperationException()
        def getEncoderClass(): Class[Measure] = classOf[Measure]
    }),
    DEFAULT_CODEC_REGISTRY
  )

  val con: MongoDatabase = MongoClient.apply()
    .getDatabase("recipes")
    .withCodecRegistry(MongoDB.codecRegistry)
}