ReactiveMongo Play Plugin Extensions

JsonFormats.scala

package json

import reactivemongo.bson._
import reactivemongo.bson.handlers.DefaultBSONHandlers._

import play.api.libs.json._
import play.api.libs.json.Json._
import play.api.libs.json.util._
import play.api.libs.json.Writes._
import play.api.libs.functional.syntax._

object Formats {
  
  val objectIDRegExFormat = "^[0-9a-fA-F]{24}$".r
  def isObjectIDValid(input: String): Boolean = (objectIDRegExFormat findFirstIn input).nonEmpty

  implicit object ObjectIdReads extends Format[BSONObjectID] {
    def reads(json: JsValue): JsResult[BSONObjectID] = json.asOpt[JsObject] map { oid =>
      (oid \ "$oid" ).asOpt[String] map { str =>
        if (isObjectIDValid(str))
        JsSuccess(new BSONObjectID(str))
      else
        JsError("Invalid ObjectId %s".format(str))
      } getOrElse (JsError("Value is not an ObjectId"))
    } getOrElse (JsError("Value is not an ObjectId"))

    def writes(oid: BSONObjectID): JsValue = Json.obj("$oid" -> JsString(oid.stringify))
  }

}

MongoModel.scala

package models.mongo

import scala.concurrent.{Future, ExecutionContext}

// Reactive Mongo imports
import reactivemongo.api._
import reactivemongo.bson._
import reactivemongo.bson.handlers.DefaultBSONHandlers._
import reactivemongo.core.commands._

// Reactive Mongo plugin
import play.modules.reactivemongo._
import play.modules.reactivemongo.PlayBsonImplicits._

// Play Json imports
import play.api.libs.json._
import json.Formats._

trait MongoModel[T, ID] {

  val collection: Collection
  implicit val ec: ExecutionContext

  /**
   * Find all items for the given query.
   * Implicit JsValue -> T must be in scope
  */
  def find[T](q: QueryBuilder)(implicit reader: Reads[T]): Future[List[T]] = {
    val jsonValuesFuture: Future[List[JsValue]] = collection.find[JsValue](q).toList
    // Transform future of JSON values to future of T, but only keep the successfully parsed ones
    jsonValuesFuture map { jsonValues =>
      jsonValues map { json =>
        Json.fromJson[T](json) // JsResult
      } collect { case JsSuccess(transaction, _) => transaction }
    }
  }

  /**
   * Find all items for the given JsValue query.
   * Implicit JsValue -> T must be in scope
  */
  def find[T](q: JsValue)(implicit reader: Reads[T]): Future[List[T]] = find[T](QueryBuilder().query(q))

  /**
   * Find one item and maybe return it.
   * Implicit JsValue -> T must be in scope
  */
  def findOne(q: JsValue)(implicit reader: Reads[T]): Future[Option[T]] = {
    val res: Future[Option[JsValue]] = collection.find[JsValue](QueryBuilder().query(q)).headOption
    res map { jsValueOpt =>
      jsValueOpt map { value =>
        Json.fromJson[T](value).asOpt // JsResult => Option || .getOrElse directly?
      } getOrElse (None)
    }
  }

  def insert(t: T)(implicit writer: Writes[T]): Future[LastError] =
    collection.insert(Json.toJson(t))

  /*
   * Writes an updated version of a model class to the database.
   */
  //TODO def update(t: T)(implicit writer: Writes[T]): Future[LastError] =
  // collection.update()

  def removeById(id: ID)(implicit writer: Writes[ID]): Future[LastError] =
    collection.remove(Json.obj("_id" -> id))

  // -- Convenience

  /**
   * Find one item by its _id and maybe return it.
   * Implicit JsValue -> T must be in scope
   * Implicit ID -> JsValue must be in scope
  */
  def findOneById(id: ID)(implicit reader: Reads[T], writer: Writes[ID]): Future[Option[T]] =
    findOne(Json.obj("_id" -> id))

  def count(q: Option[BSONDocument] = None): Future[Int] =
    collection.db.command(Count(collectionName = collection.name, query = q))

  def all(implicit reader: Reads[T]): Future[List[T]] =
    find[T](QueryBuilder().query(BSONDocument()))

  // For performance reasons, this is not implemented in terms of findOne, but find().limit()
  def exists: Future[Boolean] =
    collection.find[JsValue, JsValue](Json.obj()).headOption.map(_.isDefined)
}

RouteFormats.scala

package util

import play.api.mvc._

import reactivemongo.bson._

/**
 * In Build.scala, add the following:
 * routesImport += "util.RouteFormats._"
 */
object RouteFormats {

  type BSONObjectID = reactivemongo.bson.BSONObjectID

  val objectIDRegExFormat = "^[0-9a-fA-F]{24}$".r
  def isObjectIDValid(input: String): Boolean = (objectIDRegExFormat findFirstIn input).nonEmpty

  implicit object BSONObjectIDQueryStringBindable extends QueryStringBindable[BSONObjectID] {
    def bind(key: String, params: Map[String, Seq[String]]): Option[Either[String, BSONObjectID]] =
      params.get(key).flatMap(_.headOption).map { _ match {
        case str: String if (isObjectIDValid(str)) => Right(BSONObjectID(str))
        case _ => Left("Cannot parse parameter " + key + " as BSONObjectID")
      }
    }

    def unbind(key: String, value: BSONObjectID): String = key + "=" + value.stringify
  }

  /* Allows to use BSONObjectID as a path variable */
  implicit object BSONObjectIDPathBindable extends PathBindable[BSONObjectID] {
    def bind(key: String, value: String) = value match {
      case str: String if (isObjectIDValid(str)) => Right(BSONObjectID(str))
      case _ => Left("Cannot parse parameter " + key + " as BSONObjectID")
    }

    def unbind(key: String, value: BSONObjectID): String = value.stringify
  }

  implicit def BSONObjectIDJavascriptLitteral = new JavascriptLitteral[BSONObjectID] {
    def to(value: BSONObjectID) = value.stringify
  }
}

Really helpful! Thank you!