Gist for scala-salat issue: https://groups.google.com/forum/?hl=en_US&fromgroups#!topic/scala-salat/IAiLu7yDFT0

Issues.json

/*
(1) The findOne method stopped working
(2) I get a weird ClassCastException from MegaPoll to MegaPoll, even though I use a custom context and define dao as a val.

Polls now get persisted as:
*/

{
  "_id":ObjectId("4fe18acb286f6aca172f95bb"),
  "_typeHint":"util.mongo.MegaPoll",
  "poll":{
    "_typeHint":"controllers.ResponsePoll",
    "id":NumberLong(1),
    "name":"Posted via API",
    "created":NumberLong("1340181194808"),
    "question":"Was this created in scenario 0?",
    "option_a":"Sure was!",
    "option_b":"I don't know.",
    "expires":NumberLong("1338220191555"),
    "short_url":"http://localhost:9000/alpha/#polls/1",
    "user":{
      "_typeHint":"controllers.ResponseUser",
      "id":NumberLong(2),
      "name":"Juan M Uys",
      "mobile":"+447702783956",
      "created":NumberLong("1340181194512"),
      "avatarURL":"https://secure.gravatar.com/avatar/c22bbf2aac2a3841d80f5363d73e3ebe?s=50&d=https://d37eplffuz3ep4.cloudfront.net/av67.png"
    }
  },
  "votes":[

  ]
}

Mongo-new.scala

package util.mongo

import play.api.Play
import com.mongodb.casbah._
import play.api.Play.current
import com.novus.salat._
import com.novus.salat.dao.ModelCompanion
import com.novus.salat.dao.SalatDAO
import com.mongodb.casbah.Imports._
import se.radley.plugin.salat._
import controllers.ResponsePoll
import controllers.ResponseUser
import controllers.ResponseVote
import models.PollResults
import models.Poll

import com.mongodb.casbah.Imports._

import globals.ctx

object MegaPoll extends ModelCompanion[MegaPoll, ObjectId] {

  val collection = mongoCollection("polls")
  val dao = new SalatDAO[MegaPoll, ObjectId](collection = collection) {}

  def findOneByPollId(pollId: Long): Option[MegaPoll] = dao.findOne(MongoDBObject("poll.id" -> pollId))
  
  /**
   * Update the MegaPoll by Mongo Object ID.
   * 
   * If the latter wasn't provided, we get it from the database.
   */
  def update(updated: MegaPoll, mongoObjectId: Option[String]): Unit = mongoObjectId match {
    
    case Some(id) => {
      import com.mongodb.casbah.commons.conversions.scala._
      RegisterJodaTimeConversionHelpers()
      val o = MongoDBObject("$set" -> MongoDBObject("poll" -> updated))
      dao.update(MongoDBObject("_id" -> new ObjectId(id)), o, false, false, new WriteConcern)
    }
    case None => {
      Poll.findById(updated.poll.id) match {
        case Some(poll) if poll.mongo_object_id.isDefined => {
          val o = MongoDBObject("$set" -> MongoDBObject("poll" -> updated))
          dao.update(MongoDBObject("_id" -> new ObjectId(poll.mongo_object_id.get)), o, false, false, new WriteConcern)
        }
        case None => play.Logger.error("The object ID should have been saved when the poll=%s was originally created." format updated.poll.id)
      }
    }
  }
}

case class MegaPoll(poll: ResponsePoll, results: Option[PollResults], votes: List[ResponseVote])

// for https://groups.google.com/forum/?hl=en_US&fromgroups#!topic/scala-salat/IAiLu7yDFT0

Mongo-old.scala

package util

import play.api.Play
import com.mongodb.casbah._
import play.api.Play.current
import com.novus.salat._
import com.novus.salat.dao._
import com.mongodb.casbah.Imports._
import se.radley.plugin.salat._
import controllers.ResponsePoll
import controllers.ResponseUser
import controllers.ResponseVote
import models.PollResults
import models.Poll

import com.mongodb.casbah.Imports._

object MegaPoll extends ModelCompanion[MegaPoll, ObjectId] {

  val collection = mongoCollection("polls")
  val dao = new SalatDAO[MegaPoll, ObjectId](collection = collection) {}

  def findOneByPollId(pollId: Long): Option[MegaPoll] = dao.findOne(MongoDBObject("poll._id" -> pollId))
  
  /**
   * Update the MegaPoll by Mongo Object ID.
   * 
   * If the latter wasn't provided, we get it from the database.
   */
  def update(updated: MegaPoll, mongoObjectId: Option[String]) = mongoObjectId match {
    
    case Some(id) => {
      import com.mongodb.casbah.commons.conversions.scala._
      RegisterJodaTimeConversionHelpers()
      dao.update(MongoDBObject("_id" -> new ObjectId(id)), updated, false, false, new WriteConcern)
    }
    case None => {
      Poll.findById(updated.poll.id) match {
        case Some(poll) if poll.mongo_object_id.isDefined => {
          dao.update(MongoDBObject("_id" -> new ObjectId(poll.mongo_object_id.get)), updated, false, false, new WriteConcern)
        }
        case None => play.Logger.error("The object ID should have been saved when the poll=%s was originally created." format updated.poll.id)
      }
    }
  }
}

case class MegaPoll(poll: ResponsePoll, results: Option[PollResults], votes: List[ResponseVote])

// for https://groups.google.com/forum/?hl=en_US&fromgroups#!topic/scala-salat/IAiLu7yDFT0