private void HandleResponse(NotificationResponse response)
{
var notificationItem = response.NotificationItem;
// Handle responses according to:
// http://msdn.microsoft.com/en-us/library/ff941100(v=VS.92).aspx
// Notification was sent to the queue and will be received. All is good.
if (response.NotificationStatus == NotificationStatusReceived)
{
/*if (response.DeviceConnectionStatus == DeviceConnectionStatusTemporarilyDisconnected)
{
// We may want to do something clever here though, like not send anything else
// to this device for an hour or so.
}*/
return;
}
// If the notification was suppressed, don't do anything.
// This could happen because the tile isn't pinned to the start page
// or that the client isn't properly configured.
// We could potentially implement the "Ask user to pin"-recipe
if (response.NotificationStatus == NotificationStatusSuppressed)
{
return;
}
// If the subscription has expired, remove it
if (response.SubscriptionStatus == SubscriptionStatusExpired)
{
_registrator.Unregister(notificationItem.ClientUniqueId);
return;
}
// If the queue is full, retry in a few minutes
if (response.NotificationStatus == NotificationStatusQueueFull &&
(
response.DeviceConnectionStatus == DeviceConnectionStatusConnected ||
response.DeviceConnectionStatus == DeviceConnectionStatusTemporarilyDisconnected
)
)
{
notificationItem.FailedAttempts++;
if (notificationItem.FailedAttempts <= notificationItem.MaxNumberOfAttempts)
{
// Wait exponentially longer for each failed attempt
// Start with 2 minutes, then 4, then 8 etc.
var minutesToWait = (2 ^ notificationItem.FailedAttempts);
// Re-send this notification in a few minutes
_queue.EnqueueItem(notificationItem, DateTime.Now.AddMinutes(minutesToWait));
}
return;
}
// If server returned a 503, retry in a few minutes
if (response.StatusCode == 503)
{
notificationItem.FailedAttempts++;
if (notificationItem.FailedAttempts <= notificationItem.MaxNumberOfAttempts)
{
// Wait exponentially longer for each failed attempt
// Start with 2 minutes, then 4, then 8 etc.
var minutesToWait = (2 ^ notificationItem.FailedAttempts);
// Re-send this notification in a few minutes
_queue.EnqueueItem(notificationItem, DateTime.Now.AddMinutes(minutesToWait));
}
return;
}
// Device is in an inactive state. We may retry once every hour
if (response.StatusCode == 412 &&
response.NotificationStatus == NotificationStatusDropped &&
response.DeviceConnectionStatus == DeviceConnectionStatusInactive)
{
notificationItem.FailedAttempts++;
if (notificationItem.FailedAttempts <= notificationItem.MaxNumberOfAttempts)
{
// Re-send this notification in an hour
_queue.EnqueueItem(notificationItem, DateTime.Now.AddHours(1));
}
return;
}
// Throttling limit reached, let's try again in an hour
if (response.NotificationStatus == NotificationStatusDropped && response.SubscriptionStatus == SubscriptionStatusActive)
{
notificationItem.FailedAttempts++;
if (notificationItem.FailedAttempts <= notificationItem.MaxNumberOfAttempts)
{
// Re-send this notification in an hour
_queue.EnqueueItem(notificationItem, DateTime.Now.AddHours(1));
}
return;
}
}
private NotificationResponse SendRequest(string subscriptionUri, byte[] notificationMessage, NotificationKind kind)
{
HttpWebRequest sendNotificationRequest = (HttpWebRequest)WebRequest.Create(subscriptionUri);
// HTTP POST is the only allowed method to send the notification.
sendNotificationRequest.Method = "POST";
// The optional custom header X-MessageID uniquely identifies a notification message. If it is present, the
// same value is returned in the notification response. It must be a string that contains a UUID.
sendNotificationRequest.Headers.Add("X-MessageID", Guid.NewGuid().ToString());
if (kind == NotificationKind.Tile)
{
sendNotificationRequest.ContentType = "text/xml";
sendNotificationRequest.Headers.Add("X-WindowsPhone-Target", "token");
}
else if (kind == NotificationKind.Toast)
{
sendNotificationRequest.ContentType = "text/xml";
sendNotificationRequest.Headers.Add("X-WindowsPhone-Target", "toast");
}
// TODO Add support for other notification classes
var notificationClass = ((int)NotificationClass.Immediately) + (int)kind;
sendNotificationRequest.Headers.Add("X-NotificationClass", notificationClass.ToString());
// Sets the web request content length.
sendNotificationRequest.ContentLength = notificationMessage.Length;
using (Stream requestStream = sendNotificationRequest.GetRequestStream())
{
requestStream.Write(notificationMessage, 0, notificationMessage.Length);
}
// Sends the notification and make sure we handle the response eventually
HttpWebResponse response;
try
{
response = (HttpWebResponse)sendNotificationRequest.GetResponse();
}
catch(WebException ex)
{
response = ex.Response as HttpWebResponse;
}
var notResponse = new NotificationResponse
{
StatusCode = (int)response.StatusCode,
NotificationStatus = response.Headers["X-NotificationStatus"],
SubscriptionStatus = response.Headers["X-SubscriptionStatus"],
DeviceConnectionStatus = response.Headers["X-DeviceConnectionStatus"]
};
return notResponse;
}