User notification examples

6 min

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.

[ServiceConfiguration(typeof (INotificationFormatter))]
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.

[ServiceConfiguration(typeof (IUserNotificationFormatter))]
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 retrieving a particular channel's 25 latest unread notifications. It uses the formatter from the previous example; 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.

[ServiceConfiguration(typeof (INotificationProvider))]
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,
    Action<ProviderNotificationMessage,
    Exception > failedAction) {
    foreach(var item in messages)
    Console.WriteLine(item.Content);
    return Task.FromResult(true);
  }
  public bool IsDisabled {
    get {
      return DateTime.Now < DateTime.Today.AddHours(6);
    }
  }
  public string DisabledReason {
    get {
      return "No printing after midnight";
    }
  }
}

Subscriptions

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;
}