Creating Azure Notifications Hub Push Notifications using Node Script

Windows Azure Mobile Services has great built-in support for making Push Notifications; however there’s a better more scalable option using the Notifications Hub which is part of the Service Bus group of services.

We can call the hub from external backend services using the Windows Azure Service Bus SDK (NuGet PM> Install-Package WindowsAzure.ServiceBus) and this is fairly well documented; however if you want to do a direct replacement for the build-in Push Notifications using Notifications Hub, it’s not so well documented. I did some digging in the source to work out how to use it: https://github.com/WindowsAzure/azure-sdk-for-node

In our Mobile Services scripts we can make use of NPM packages which we install ourselves and pre-installed packages like the Windows Azure SDK for Node which we will use for calling the Hub.

Accessing the Notifications Hub

We need two things to allow us to connect to the hub and those are the DefaultFullSharedAccessSignature which you can get from the Notifications Hub Dashboard and the Hub name. We can declare these as variables like this:

var CONNECTION_STRING = "Endpoint=sb://myapp.servicebus.windows.net/;SharedAccessKeyName=DefaultFullSharedAccessSignature;SharedAccessKey=XXXXXXXXXXXXXXXXXXXXXxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx=";

var HUB_NAME = "MyHubName";

Now to interact with the Notifications hub, we get a reference to the Azure package like this:

var azure = require("azure");

Then create a NotificationHubService like this:

var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

All the native PNS send methods have prototypes similar to this:

MpnsService.prototype.send = function (tags, payload, targetName, notificationClass, optionsOrCallback, callback)

The Notifications class is the batching interval (how quick it’s sent).

Windows Phone MPNS Notofications

Following are examples of sending toast and tiles to Windows Phone apps using the MPNS provider:   

function sendToastHubMpns(text1, text2, tagExpression)

{

    var azure = require("azure");

    var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

   

    var toast = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +

    "<wp:Notification xmlns:wp=\"WPNotification\">" +

        "<wp:Toast>" +

            "<wp:Text1>" + text1 + "</wp:Text1>" +

            "<wp:Text2>" + text2 + "</wp:Text2>" +

        "</wp:Toast> " +

    "</wp:Notification>";

   

    notificationHubService.mpns.send(tagExpression, toast, "toast", 2, function(error) {

    if (error) {

        console.error(error);

    }});

}

function sendTileHubMpns(backTitle, backContent, tagExpression)

{

  var azure = require("azure");

  var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

   

  var tile = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +

      "<wp:Notification xmlns:wp=\"WPNotification\" Version=\"2.0\">" +

         "<wp:Tile Template=\"FlipTile\">" +

              "<wp:BackTitle>" + backTitle + "</wp:BackTitle>" +

              "<wp:BackContent>" + backContent + "</wp:BackContent>" +

              "<wp:WideBackContent>" + backContent + "</wp:WideBackContent>" +

         "</wp:Tile> " +

      "</wp:Notification>";

 

    notificationHubService.mpns.send(tagExpression, tile, "token", 1, function(error) {

    if (error) {

        console.error(error);

    }});

}

Windows 8 WNS Notifications

Following are examples of sending toast, tile and badge notifications to Windows 8 apps using the WNS provider:   

function sendToastHubWns(text1, text2, text3, tagExpression)

{

  var azure = require("azure");

  var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

 

  var toast = "<toast>" +

    "<visual>" +

      "<binding template=\"ToastText04\">" +

        "<text id=\"1\">" + text1 + "</text>" +

        "<text id=\"2\">" + text2 + "</text>" +

        "<text id=\"3\">" + text3 + "</text>" +

        "</binding>" +

      "</visual>" +

    "</toast>";

    notificationHubService.wns.send(tagExpression, toast, "wns/toast", 2, function(error) {

    if (error) {

        console.error(error);

    }});

}

function sendTileHubWns(text1, text2, text3, tagExpression)

{

    var azure = require("azure");

    var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

   

    var tile = "<tile>" +

    "<visual>" +

      "<binding template=\"TileSquareText01\">" +

        "<text id=\"1\">" + text1 + "</text>" +

        "<text id=\"2\">" + text2 + "</text>" +

        "<text id=\"3\">" + text3 + "</text>" +

      "</binding>" +

    "</visual>" +

    "</tile>";

 

    notificationHubService.wns.send(tagExpression, tile, "wns/tile", 2, function(error) {

    if (error) {

        console.error(error);

    }});

}

function sendBadgeHubWns(value, tagExpression)

{

    var azure = require("azure");

    var notificationHubService = azure.createNotificationHubService(HUB_NAME, CONNECTION_STRING);

   

    var badge = "<badge value=\"" + value + "\" />";

 

    notificationHubService.wns.send(tagExpression, badge, "wns/badge", 2, function(error) {

    if (error) {

        console.error(error);

    }});

}

These functions can be called like this:

function sendAllHubNotifications(message)

{

  sendToastHubMpns("My Application", message, null);

  sendTileHubMpns("My Application ", message, null);

  sendToastHubWns("My Application ", "Here’s a notification", message, null);

  sendTileHubWns("My Application ", " Here’s a notification ", message, null;

  sendBadgeHubWns("alert",  null);

}

Notice there is a tagExpression variable which we have set to null. We can use this to target notifications at user’s interests which are registered in the app:

function sendAllHubNotifications(message)

{

  sendToastHubWns("My Application ", "Here’s a notification", message, "NEWS");

  sendTileHubWns("My Application ", " Here’s a notification ", message, "NEWS");

  sendBadgeHubWns("alert", "NEWS");

}

I managed to get Windows 8 to work with this but not Windows Phone 8

Registering with the Hub from a Windows 8 App

This example shows how to register a Windows 8 Store App with the DefaultListenSharedAccessSignature connection string this time (from the Notifocations Hub Dashboard). This registers two tags, but you can use null to receive everything:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using Microsoft.WindowsAzure.MobileServices;

using Newtonsoft.Json.Linq;

using Microsoft.WindowsAzure.Messaging;

namespace MyApp

{

    internal class MyAppPush

    {

        private const string HUB_NAME = "myapp";

        private const string CONNECTION_STRING = "Endpoint=sb://myapp.servicebus.windows.net/;SharedAccessKeyName=DefaultListenSharedAccessSignature;SharedAccessKey=/XXXXXXXXXXXXXXXXXXXXXXXXxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx=";

        public async static void UploadChannel()

        {

            var channel = await Windows.Networking.PushNotifications.PushNotificationChannelManager.CreatePushNotificationChannelForApplicationAsync();

            var token = Windows.System.Profile.HardwareIdentification.GetPackageSpecificToken(null);

            string installationId = Windows.Security.Cryptography.CryptographicBuffer.EncodeToBase64String(token.Id);

            try

            {

                // Register with hub

                var hub = new NotificationHub(HUB_NAME, CONNECTION_STRING);

                var result = await hub.RegisterNativeAsync(channel.Uri, new string[] { "NEWS", "SUPPORT" });

            }

            catch (Exception ex)

            {

                System.Diagnostics.Debug.WriteLine(ex.ToString());

            }

        }

    }

}

Windows Phone 8 apps are registered in the same way, but they have a slightly different mechanism as they have an event when the URI changes which needs to be used for registration.