inanna-malick/pusher.scala

## pusher.scala
//send messages via Pusher API in play 2.4
import play.api.libs.json.{ Writes, Json }
import play.api.libs.ws.{ WSResponse, WSClient }
import play.api.libs.ws.ning.NingWSClient
import java.security.MessageDigest
import java.math.BigInteger
import javax.crypto.Mac
import javax.crypto.spec.SecretKeySpec
import scala.concurrent.{ ExecutionContext, Future }

object Pusher {

  val appId = "app_id"
  val key = "key"
  val secret = "secret"
  val domain = "api.pusherapp.com"

  val client = NingWSClient()

  val p = new Pusher(client, PusherConfig(appId, key, secret, domain))

  case class Msg(foo: String, bar: String) extends PusherEvent {
    val eventName = "test event with type msg"
  }

  implicit val ec = scala.concurrent.ExecutionContext.Implicits.global

  implicit val writes = Json.writes[Msg]

  def trigger() = p.trigger("test_channel", Msg("hello", "world")).onSuccess {
    case resp =>
      println(resp)
      println(resp.body)
  }

}

case class PusherConfig(appId: String, apiKey: String, secret: String, domain: String)

trait PusherEvent {
  val eventName: String
}

class Pusher(client: WSClient, pusherConfig: PusherConfig) {
  import pusherConfig.{ appId, apiKey, secret, domain }

  //current timestamp in seconds, used for pusher auth
  def authTimestamp() = System.currentTimeMillis() / 1000

  //create and send a signed request: https://pusher.com/docs/rest_api#auth-signature
  def trigger[T <: PusherEvent](channel: String, message: T)(implicit writes: Writes[T], ec: ExecutionContext): Future[WSResponse] = {

    val url = "/apps/"+appId+"/channels/"+channel+"/events"

    val body = Json.toJson(message).toString()

    // request signature component: query parameters sorted by key, with keys converted to lowercase,
    // then joined as in the query string. Note that the string must not be url escaped
    // (e.g. given the keys auth_key: foo, Name: Something else, you get auth_key=foo&name=Something else)
    val params = List(
      "auth_key" -> apiKey,
      "auth_timestamp" -> authTimestamp().toString,
      "auth_version" -> "1.0",
      "name" -> message.eventName,
      "body_md5" -> md5(body)
    ).sortBy { case (key, _) => key }

    val encodedParams =
      params.map { case (key, value) => key+"="+value }.mkString("&")

    val toSign = List("POST", url, encodedParams).mkString("\n")
    val signature = sha256(toSign, secret)

    val signedParams = params ++ List("auth_signature" -> signature)

    client.url("http://"+domain + url).withQueryString(signedParams: _*).post(body)
  }

  private[this] def byteArrayToString(data: Array[Byte]): String = {
    val hash = new BigInteger(1, data).toString(16)
    "0" * (32 - hash.length) + hash
  }

  private[this] def md5(s: String): String =
    byteArrayToString(MessageDigest.getInstance("MD5").digest(s.getBytes("US-ASCII")))

  private[this] def sha256(s: String, secret: String): String = {
    val mac = Mac.getInstance("HmacSHA256")
    mac.init(new SecretKeySpec(secret.getBytes, "HmacSHA256"))
    val digest = mac.doFinal(s.getBytes)
    String.format("%0"+(digest.length << 1)+"x", new BigInteger(1, digest))
  }

}

## test.html
<!DOCTYPE html>
<head>
  <title>Pusher Test</title>
  <script src="https://js.pusher.com/3.0/pusher.min.js"></script>
  <script>
    // Enable pusher logging - don't include this in production
    Pusher.log = function(message) {
      if (window.console && window.console.log) {
        window.console.log(message);
      }
    };

    var pusher = new Pusher('key', {
      encrypted: true
    });
    var channel = pusher.subscribe('test_channel');
    channel.bind('my_event', function(data) {
      alert(data.message);
    });
  </script>
</head>
	//send messages via Pusher API in play 2.4
	import play.api.libs.json.{ Writes, Json }
	import play.api.libs.ws.{ WSResponse, WSClient }
	import play.api.libs.ws.ning.NingWSClient
	import java.security.MessageDigest
	import java.math.BigInteger
	import javax.crypto.Mac
	import javax.crypto.spec.SecretKeySpec
	import scala.concurrent.{ ExecutionContext, Future }

	object Pusher {

	val appId = "app_id"
	val key = "key"
	val secret = "secret"
	val domain = "api.pusherapp.com"

	val client = NingWSClient()

	val p = new Pusher(client, PusherConfig(appId, key, secret, domain))

	case class Msg(foo: String, bar: String) extends PusherEvent {
	val eventName = "test event with type msg"
	}

	implicit val ec = scala.concurrent.ExecutionContext.Implicits.global

	implicit val writes = Json.writes[Msg]

	def trigger() = p.trigger("test_channel", Msg("hello", "world")).onSuccess {
	case resp =>
	println(resp)
	println(resp.body)
	}

	}

	case class PusherConfig(appId: String, apiKey: String, secret: String, domain: String)

	trait PusherEvent {
	val eventName: String
	}

	class Pusher(client: WSClient, pusherConfig: PusherConfig) {
	import pusherConfig.{ appId, apiKey, secret, domain }

	//current timestamp in seconds, used for pusher auth
	def authTimestamp() = System.currentTimeMillis() / 1000

	//create and send a signed request: https://pusher.com/docs/rest_api#auth-signature
	def trigger[T <: PusherEvent](channel: String, message: T)(implicit writes: Writes[T], ec: ExecutionContext): Future[WSResponse] = {

	val url = "/apps/"+appId+"/channels/"+channel+"/events"

	val body = Json.toJson(message).toString()

	// request signature component: query parameters sorted by key, with keys converted to lowercase,
	// then joined as in the query string. Note that the string must not be url escaped
	// (e.g. given the keys auth_key: foo, Name: Something else, you get auth_key=foo&name=Something else)
	val params = List(
	"auth_key" -> apiKey,
	"auth_timestamp" -> authTimestamp().toString,
	"auth_version" -> "1.0",
	"name" -> message.eventName,
	"body_md5" -> md5(body)
	).sortBy { case (key, _) => key }

	val encodedParams =
	params.map { case (key, value) => key+"="+value }.mkString("&")

	val toSign = List("POST", url, encodedParams).mkString("\n")
	val signature = sha256(toSign, secret)

	val signedParams = params ++ List("auth_signature" -> signature)

	client.url("http://"+domain + url).withQueryString(signedParams: _*).post(body)
	}

	private[this] def byteArrayToString(data: Array[Byte]): String = {
	val hash = new BigInteger(1, data).toString(16)
	"0" * (32 - hash.length) + hash
	}

	private[this] def md5(s: String): String =
	byteArrayToString(MessageDigest.getInstance("MD5").digest(s.getBytes("US-ASCII")))

	private[this] def sha256(s: String, secret: String): String = {
	val mac = Mac.getInstance("HmacSHA256")
	mac.init(new SecretKeySpec(secret.getBytes, "HmacSHA256"))
	val digest = mac.doFinal(s.getBytes)
	String.format("%0"+(digest.length << 1)+"x", new BigInteger(1, digest))
	}

	}
	<!DOCTYPE html>
	<head>
	<title>Pusher Test</title>
	<script src="https://js.pusher.com/3.0/pusher.min.js"></script>
	<script>
	// Enable pusher logging - don't include this in production
	Pusher.log = function(message) {
	if (window.console && window.console.log) {
	window.console.log(message);
	}
	};

	var pusher = new Pusher('key', {
	encrypted: true
	});
	var channel = pusher.subscribe('test_channel');
	channel.bind('my_event', function(data) {
	alert(data.message);
	});
	</script>
	</head>