None_iff_all_are_None.scala

case class MenuItemPortion(title: String, price: String)

object MenuItemPortion extends Convertable[MenuItemPortion] {
  override def readFrom(dbo: MongoDBObject): Option[MenuItemPortion] = {
    val title: Option[String] = dbo.getAs[String]("title")
    val price: Option[String]= dbo.getAs[String]("price")
    if (title.isEmpty && price.isEmpty) None
    else Some(MenuItemPortion(title.getOrElse(""), price.getOrElse("")))
  }
}

val values = 
   for {
      name <- Seq("title", "price") 
      value <- dbo.getAs[String](name)
  } yield name -> value

def value(name: String) = values.getOrElse(name, "")

if(values.isEmpty) None
else Some(MenuItemPortion(value("title"), value("price")))