Reactive Scala Driver for MongoDB

import javax.inject.Inject

import play.api.mvc.{ AbstractController, ControllerComponents }
import play.modules.reactivemongo._

class MyController @Inject() (
  components: ControllerComponents,
  val reactiveMongoApi: ReactiveMongoApi
) extends AbstractController(components)
  with MongoController with ReactiveMongoComponents {

  // ...
}

import javax.inject.Inject

import play.api.mvc.{ AbstractController, ControllerComponents }
import play.modules.reactivemongo._

class MyController @Inject() (
  components: ControllerComponents,
  val reactiveMongoApi: ReactiveMongoApi
) extends AbstractController(components)
  with MongoController with ReactiveMongoComponents {

}

import play.api.ApplicationLoader

import play.modules.reactivemongo.ReactiveMongoApiFromContext

class MyApplicationLoader extends ApplicationLoader {
  def load(context: ApplicationLoader.Context) =
    new MyComponents(context).application
}

class MyComponents(context: ApplicationLoader.Context)
    extends ReactiveMongoApiFromContext(context) {

  lazy val router = play.api.routing.Router.empty
  lazy val httpFilters = Seq.empty[play.api.mvc.EssentialFilter]
}

import javax.inject.Inject

import play.modules.reactivemongo._

class MyComponent @Inject() (
  val defaultApi: ReactiveMongoApi, // corresponds to 'mongodb.uri'
  @NamedDatabase("bar") val barApi: ReactiveMongoApi // 'mongodb.bar'
) {

}

import javax.inject.Inject

import play.api.mvc.{ AbstractController, ControllerComponents }
import reactivemongo.api.bson.BSONObjectID

class Application @Inject() (
  components: ControllerComponents) extends AbstractController(components) {
  def foo(id: BSONObjectID) = Action {
    Ok(s"Foo: ${id.stringify}")
  }
}

import javax.inject.Inject

import scala.concurrent.Future

import akka.stream.Materializer

import play.api.mvc.{ AbstractController, ControllerComponents }

import play.api.libs.concurrent.Execution.Implicits.defaultContext
import play.api.libs.json._

import reactivemongo.api.gridfs.ReadFile
import reactivemongo.api.bson.{ BSONDocument, BSONValue }

import play.modules.reactivemongo.{
  MongoController, ReactiveMongoComponents, ReactiveMongoApi
}

class MyController @Inject() (
  components: ControllerComponents,
  materializer: Materializer,
  val reactiveMongoApi: ReactiveMongoApi
) extends AbstractController(components)
  with MongoController with ReactiveMongoComponents {

  implicit def m: Materializer = materializer

  // gridFSBodyParser from `MongoController`
  val fsParser = gridFSBodyParser(reactiveMongoApi.asyncGridFS)
  
  def upload = Action(fsParser) { request =>
    // here is the future file!
    val file: ReadFile[BSONValue, BSONDocument] = request.body.files.head.ref

    // do something with `file`
    Ok
  }
}

package controllers

import javax.inject.Inject

import scala.concurrent.{ ExecutionContext, Future }

import play.api.Logger
import play.api.mvc.{ AbstractController, ControllerComponents }
import play.api.libs.functional.syntax._
import play.api.libs.json._

// Reactive Mongo imports
import reactivemongo.api.{ Cursor, ReadPreference }
import reactivemongo.api.bson.collection.{
  BSONCollection, BSONSerializationPack
}

import play.modules.reactivemongo.{ // ReactiveMongo Play2 plugin
  MongoController,
  ReactiveMongoApi,
  ReactiveMongoComponents
}

// BSON-JSON conversions/collection
import reactivemongo.play.json.compat._,
  json2bson.{ toDocumentReader, toDocumentWriter }

/*
 * Example using ReactiveMongo + Play JSON library.
 *
 * There are two approaches demonstrated in this controller:
 * - using JsObjects directly
 * - using case classes that can be turned into JSON using Reads and Writes.
 *
 * This controller uses JsObjects directly.
 *
 * Instead of using the default Collection implementation (which interacts with
 * BSON structures + BSONReader/BSONWriter), we use a specialized
 * implementation that works with JsObject + Reads/Writes.
 *
 * Of course, you can still use the default Collection implementation
 * (BSONCollection.) See ReactiveMongo examples to learn how to use it.
 */
class Application @Inject() (
  components: ControllerComponents,
  val reactiveMongoApi: ReactiveMongoApi,
) extends AbstractController(components)
    with MongoController with ReactiveMongoComponents {

  //val _ = implicitly[OWrites[JsObject]]
  //val _ = implicitly[ToValue]
  val _ = implicitly[reactivemongo.api.bson.BSONDocumentWriter[JsObject]]

  implicit def ec: ExecutionContext = components.executionContext

  /*
   * Resolves a collection.
   *
   * The deprecated `.db` function should be replaced as there by `.database`.
   *
   * Note that the `collection` is not a `val`, but a `def`. We do _not_ store
   * the collection reference to avoid potential problems in development with
   * Play hot-reloading.
   */
  def collection: Future[BSONCollection] =
    reactiveMongoApi.database.map(_.collection[BSONCollection]("persons"))

  def index = Action { Ok("works") }

  def create(name: String, age: Int) = Action.async {
    val json = Json.obj(
      "name" -> name,
      "age" -> age,
      "created" -> new java.util.Date().getTime())

    collection.flatMap(_.insert.one(json)).map(lastError =>
      Ok("Mongo LastError: %s".format(lastError)))
  }

  def createFromJson = Action.async(parse.json) { request =>
    import play.api.libs.json.Reads._
    /*
     * request.body is a JsValue.
     * There is an implicit Writes that turns this JsValue as a JsObject,
     * so you can call insert.one() with this JsValue.
     * (insert.one() takes a JsObject as parameter, or anything that can be
     * turned into a JsObject using a Writes.)
     */
    val transformer: Reads[JsObject] =
      Reads.jsPickBranch[JsString](__ \ "firstName") and
        Reads.jsPickBranch[JsString](__ \ "lastName") and
        Reads.jsPickBranch[JsNumber](__ \ "age") reduce

    request.body.transform(transformer).map { result =>
      collection.flatMap(_.insert.one(result)).map { lastError =>
        Logger.debug(s"Successfully inserted with LastError: $lastError")
        Created
      }
    }.getOrElse(Future.successful(BadRequest("invalid json")))
  }

  def findByName(name: String) = Action.async {
    // let's do our query
    val cursor: Future[Cursor[JsObject]] = collection.map {
      // find all people with name `name`
      _.find(Json.obj("name" -> name)).
        // sort them by creation date
        sort(Json.obj("created" -> -1)).
        // perform the query and get a cursor of JsObject
        cursor[JsObject](ReadPreference.primary)
    }

    // gather all the JsObjects in a list
    val futurePersonsList: Future[List[JsObject]] =
      cursor.flatMap(_.collect[List](-1, Cursor.FailOnError[List[JsObject]]()))

    // transform the list into a JsArray
    val futurePersonsJsonArray: Future[JsArray] =
      futurePersonsList.map { persons => Json.arr(persons) }

    // everything's ok! Let's reply with the array
    futurePersonsJsonArray.map { persons =>
      Ok(persons)
    }
  }
}

package models

case class User(
  age: Int,
  firstName: String,
  lastName: String,
  feeds: List[Feed])

case class Feed(
  name: String,
  url: String)

object JsonFormats {
  import play.api.libs.json.Json

  // Generates Writes and Reads for Feed and User thanks to Json Macros
  implicit val feedFormat = Json.format[Feed]
  implicit val userFormat = Json.format[User]
}

import reactivemongo.play.json.compat._

package controllers

import javax.inject.Inject

import scala.concurrent.{ ExecutionContext, Future }

import play.api.Logger
import play.api.mvc.{ AbstractController, ControllerComponents }
import play.api.libs.json._

// Reactive Mongo imports
import reactivemongo.api.Cursor

import reactivemongo.api.bson.collection.BSONCollection

import play.modules.reactivemongo.{ // ReactiveMongo Play2 plugin
  MongoController,
  ReactiveMongoApi,
  ReactiveMongoComponents
}

import reactivemongo.play.json.compat._,
  json2bson.{ toDocumentReader, toDocumentWriter }

/*
 * Example using ReactiveMongo + Play JSON library.
 *
 * There are two approaches demonstrated in this controller:
 * - using JsObjects directly
 * - using case classes that can be turned into JSON using Reads and Writes.
 *
 * This controller uses case classes and their associated Reads/Writes
 * to read or write JSON structures.
 *
 * Instead of using the default Collection implementation (which interacts with
 * BSON structures + BSONReader/BSONWriter), we use a specialized
 * implementation that works with JsObject + Reads/Writes.
 *
 * Of course, you can still use the default Collection implementation
 * (BSONCollection.) See ReactiveMongo examples to learn how to use it.
 */
class ApplicationUsingJsonReadersWriters @Inject() (
  components: ControllerComponents,
  val reactiveMongoApi: ReactiveMongoApi
) extends AbstractController(components)
  with MongoController with ReactiveMongoComponents {

  implicit def ec: ExecutionContext = components.executionContext

  def collection: Future[BSONCollection] = database.map(
    _.collection[BSONCollection]("persons"))

  // ------------------------------------------ //
  // Using case classes + JSON Writes and Reads //
  // ------------------------------------------ //
  import models._
  import models.JsonFormats._

  def create = Action.async {
    val user = User(29, "John", "Smith", List(
      Feed("Slashdot news", "http://slashdot.org/slashdot.rdf")))

    // insert the user
    val futureResult = collection.flatMap(_.insert.one(user))

    // when the insert is performed, send a OK 200 result
    futureResult.map(_ => Ok)
  }

  def createFromJson = Action.async(parse.json) { request =>
    /*
     * request.body is a JsValue.
     * There is an implicit Writes that turns this JsValue as a JsObject,
     * so you can call insert.one() with this JsValue.
     * (insert.one() takes a JsObject as parameter, or anything that can be
     * turned into a JsObject using a Writes.)
     */
    request.body.validate[User].map { user =>
      // `user` is an instance of the case class `models.User`
      collection.flatMap(_.insert.one(user)).map { lastError =>
        Logger.debug(s"Successfully inserted with LastError: $lastError")
        Created
      }
    }.getOrElse(Future.successful(BadRequest("invalid json")))
  }

  def findByName(lastName: String) = Action.async {
    // let's do our query
    val cursor: Future[Cursor[User]] = collection.map {
      // find all people with name `name`
      _.find(Json.obj("lastName" -> lastName)).
        // sort them by creation date
        sort(Json.obj("created" -> -1)).
        // perform the query and get a cursor of JsObject
        cursor[User]()
    }

    // gather all the JsObjects in a list
    val futureUsersList: Future[List[User]] =
      cursor.flatMap(_.collect[List](-1, Cursor.FailOnError[List[User]]()))

    // everything's ok! Let's reply with the array
    futureUsersList.map { persons =>
      Ok(persons.toString)
    }
  }
}