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User notification examples

Shows how to work with user notifications and subscriptions for notifying users in Optimizely Content Management System (CMS).

Create and post a message

The following example shows how to create and post a notification message.

var notifier = ServiceLocator.Current.GetInstance<INotifier>();
    INotificationUser receiver;
    INotificationUser sender;
await notifier.PostNotificationAsync(new NotificationMessage()
  ChannelName = "epi.example",
  Content = "A page has been improved!",
  Subject = "Improvement",
  Recipients = new[] { receiver },
  Sender sender,
  TypeName = "PageChanged"

Create a custom formatter

The following example shows a formatter that takes a list of messages and joins their contents together.

public class StringJoinFormatter : INotificationFormatter
  public string FormatterName { get { return "epi.stringjoinformatter"; } }
  public IEnumerable<string> SupportedChannelNames { get { return new[] { "epi.example" }; } }
  public Task<IEnumerable<FormatterNotificationMessage>> 
          FormatMessagesAsync(IEnumerable<FormatterNotificationMessage> notifications,
          string recipient,
          NotificationFormat format,
          string notificationChannelName)
    var message = new FormatterNotificationMessage(notifications.SelectMany(x => x.ContainedIDs)) 
      Subject = "Joined Message",
      Content = string.Join(Environment.NewLine, notifications)
    return Task.FromResult((IEnumerable<FormatterNotificationMessage>)new[] { message });

Add user notification formatting to a custom formatter

This example adds support for user notification formatting. In this example, it makes the content text blue.

public class BlueFormatter : IUserNotificationFormatter
  public IEnumerable<string> SupportedChannelNames { get { return new[] { "epi.example" }; } }
  public Task<UserNotificationMessage> FormatUserMessageAsync(UserNotificationMessage notification)
    notification.Content = "<div style=\"color:#0000FF\">" + notification.Content + "</div>";
    return Task.FromResult(notification);

Retrieve user notifications

The following example shows how to retrieve the 25 latest unread notifications for a particular channel. It uses the formatter from the previous example; therefore, the content in the notifications will have blue text.

INotificationUser user;
var repository= ServiceLocator.Current.GetInstance<IUserNotificationRepository>();
var query = new UserNotificationsQuery
  ChannelName = "epi.example",
  User = user,
  Read = false
var notifications = repository.GetUserNotificationsAsync(query, 0, 25, UserNotificationFormattingMode.Required).Result;

Create a custom provider

The following example shows a custom provider that outputs notifications to the console.

public class PrintMessageProvider : INotificationProvider, INotificationProviderStatus
  public string ProviderName { get { return "PrintMessage"; } }
  public NotificationFormat GetProviderFormat() { return new NotificationFormat { MaxLength = 64, SupportsHtml = false }; }
  public Task 
    SendAsync(IEnumerable<ProviderNotificationMessage> messages, 
    Action<ProviderNotificationMessage> succeededAction, 
    Exception> failedAction)
    foreach (var item in messages)
    return Task.FromResult(true);
  public bool IsDisabled { get { return DateTime.Now < DateTime.Today.AddHours(6); } }
  public string DisabledReason { get { return "No printing after midnight"; } }


This example shows the usage of the subscription service.

public IEnumerable<INotificationUser> HandleContentSubscibers(ContentReference content, IList<INotificationUser> users, INotificationUser sender)
  // Make a subscriptionKey
  Uri subscriptionKey = new Uri(string.Format("epi://example/content/{0}", content.ID));
  // Subscribe all recipients of the notification, including the sender of the notification
  _subscriptionService.SubscribeAsync(subscriptionKey, users).Wait();
  _subscriptionService.SubscribeAsync(subscriptionKey, sender).Wait();
  // Get all subscribers except the sender of the notification
  var recipients = _subscriptionService.FindSubscribersAsync(subscriptionKey).Result;
  recipients = recipients.Where(u => !u.UserName.Equals(sender.UserName, StringComparison.OrdinalIgnoreCase));
  return recipients;