Azure Notification Hubs

 Azure Notification Hubs is designed to send push notifications to a wide variety of platforms, such as iOS, Android, and Windows devices. It allows for sending reliable notifications, even when the user is temporarily unavailable. Notifications can be queued and retried, ensuring that messages reach users when they are online.

To implement Azure Notification Hubs, you’ll need to follow these key steps to set it up and integrate it into your application. Here’s a detailed guide to get you started:

Steps to Implement Azure Notification Hubs:

---

1. Create a Notification Hub in Azure

1. Go to the Azure Portal and sign in.
2. In the left-hand menu, select Create a resource.
3. In the search box, type Notification Hubs and select Notification Hubs.
4. Click Create.
5. Fill in the required fields:
   • Subscription: Choose your subscription.
   • Resource Group: Select an existing group or create a new one.
   • Namespace Name: The namespace that will contain your Notification Hub.
   • Location: Choose a data center region.
   • Name: Give your Notification Hub a name.
6. Once created, navigate to your Notification Hub resource.

---

2. Get the Connection String

To send notifications, you need the connection string for your Notification Hub.

1. In the Notification Hub page, go to the Access Policies section under the Settings.
2. Select the DefaultListenSharedAccessSignature policy and copy the Connection String - Primary Key.

---

3. Configure Your Application

Now, you need to integrate the Notification Hub SDK into your application (for example, a mobile app or web application).

---

For Mobile Applications (iOS/Android/Windows):

You'll typically use Azure Notification Hubs SDKs to send and receive push notifications.

• Android (Using Firebase Cloud Messaging - FCM):

  • Install the Azure Notification Hubs SDK in your Android app using NuGet.
  • Configure your FCM (Firebase) project.
  • Register the device in the app using FCM and obtain a device token.
  • Send the device token to your Notification Hub.

• iOS (Using Apple Push Notification Service - APNs):

  • Set up APNs in the Apple Developer Console and get the Apple Push Notification Service (APNs) certificate.
  • Install Azure Notification Hubs SDK.
  • Register the iOS device for push notifications and obtain a device token.
  • Send the token to the Notification Hub for later use.

• Windows (UWP):

  • Set up Windows Push Notification Service (WNS) and get the Package SID and Client Secret.
  • Register your Windows application with Notification Hubs and send the WNS credentials to the hub.

---

For Web Applications (JavaScript):

For web apps, you can use Azure Notification Hubs with Push Notifications:

1. Include the Azure SDK:
   • Use Azure Notification Hubs JavaScript SDK to interact with the hub.
2. Register the Browser:
   • Use PushManager API to subscribe to push notifications.
3. Send Notifications:
   • Once the browser is registered, send the device token to the Notification Hub to store it for push notifications.

---

4. Send Notifications

Once the device is registered and the device token is sent to your Notification Hub, you can send a push notification to all registered devices or target specific devices.

Using Azure SDK (C# Example)

Here’s an example of how to send a push notification using the Azure Notification Hubs SDK in a .NET application:

using Microsoft.Azure.NotificationHubs;
using System;
using System.Threading.Tasks;

class Program
{
    private static string connectionString = "<your_connection_string>";
    private static string hubName = "<your_hub_name>";

    static async Task Main(string[] args)
    {
        var hub = NotificationHubClient.CreateClientFromConnectionString(connectionString, hubName);

        var message = new Dictionary<string, string>
        {
            { "message", "Hello, this is a test notification!" }
        };

        // Send a simple notification
        await hub.SendTemplateNotificationAsync(message);
        Console.WriteLine("Notification sent!");
    }
}

5. Handle Notifications on the Client

To handle the notification on the client-side (in your mobile or web app), ensure the app is configured to listen for incoming notifications.

For mobile apps, the SDK will trigger an event when a notification is received. For example, in Android:

@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
    if (remoteMessage.getData().size() > 0) {
        // Handle the notification data
    }
}

For web apps, you can use the Push API to display notifications to the user when they are received.

---

6. Configure Tags (Optional)

If you want to send notifications to a specific group of users (e.g., based on user preferences or regions), you can use tags to organize devices into segments.

• Assign tags when registering devices.
• Send notifications to specific tags.

Example of sending to a tag in C#:

await hub.SendNotificationAsync(new Dictionary<string, string> { { "message", "Important notification!" } }, "TagName");

---

Key Takeaways:

• Azure Notification Hubs allows you to send push notifications to users on different platforms (Android, iOS, Windows, Web).
• You need to create a Notification Hub, obtain the connection string, and register your devices to send notifications.
• Notifications can be sent to all users or targeted groups based on tags.