Editing notifications in Firebase

Question

I would like to receive a large number of messages from firebase notificaiton and edit its content when the message is downloaded. It's mainly about the bodysuit. E.g. Content: "Hello, #Name" Then replace the #Name value.

public override void OnMessageReceived(RemoteMessage message)
{
    message.GetNotification().Body = "";
    base.OnMessageReceived(message);

    if (message.Data.TryGetValue("action", out var messageAction))
        NotificationActionService.TriggerAction(messageAction);
}

Is this possible? Maybe there is a better solution for mass notifications and you can share your experiences. Please provide code samples. Thank you and best regards.

Answer 1

When sending a data message, include a key-value pair with a placeholder in the message body, for example:

{
  "to": "<device_token>",
  "data": {
    "title": "Greetings",
    "body": "Hello, #Name",
    "name": "John" // You can provide dynamic values for placeholders
  }
}

Android Client (using FirebaseMessagingService):

public override void OnMessageReceived(RemoteMessage message)
{
    // Ensure the message contains data payload
    if (message.Data.ContainsKey("body"))
    {
        // Get the notification body with placeholders
        string body = message.Data["body"];

        // Replace placeholders in the body (e.g., replace #Name with the actual name from the data)
        if (message.Data.ContainsKey("name"))
        {
            string name = message.Data["name"];
            body = body.Replace("#Name", name);
        }

        // Build and display the notification with the customized message body
        ShowCustomNotification(message.Data["title"], body);
    }

    // Trigger any additional actions if needed
    if (message.Data.TryGetValue("action", out var messageAction))
    {
        NotificationActionService.TriggerAction(messageAction);
    }
}

// Method to display the custom notification
private void ShowCustomNotification(string title, string body)
{
    var notificationBuilder = new NotificationCompat.Builder(this, "default_channel_id")
        .SetSmallIcon(Resource.Drawable.ic_stat_ic_notification) // Set your icon
        .SetContentTitle(title)
        .SetContentText(body)
        .SetPriority(NotificationCompat.PriorityHigh)
        .SetAutoCancel(true);

    var notificationManager = NotificationManagerCompat.From(this);
    notificationManager.Notify(0, notificationBuilder.Build());
}