// Get information about the changed messages and send to the browser via SignalR.
// A production application would typically queue a background job for reliability.
public async Task GetChangedMessagesAsync(IEnumerable <Notification> notifications)
{
List <MessageViewModel> messages = new List <MessageViewModel>();
foreach (var notification in notifications)
{
SubscriptionDetails subscription = SubscriptionCache.GetSubscriptionCache().GetSubscriptionInfo(notification.SubscriptionId);
var graphClient = GraphHelper.GetAuthenticatedClient(subscription.UserId, subscription.RedirectUrl);
// Get the message
var message = await graphClient.Me.Messages[notification.ResourceData.Id].Request()
.Select("id,subject,bodyPreview,createdDateTime,isRead,conversationId,changeKey")
.GetAsync();
// Clear the additional data from Graph (purely for display purposes)
message.AdditionalData.Clear();
MessageViewModel messageViewModel = new MessageViewModel(message, subscription.UserId);
messages.Add(messageViewModel);
}
if (messages.Count > 0)
{
NotificationService notificationService = new NotificationService();
notificationService.SendNotificationToClient(messages);
}
}
public async Task <ActionResult> Listen()
{
// Validate the new subscription by sending the token back to Microsoft Graph.
// This response is required for each subscription.
if (Request.QueryString["validationToken"] != null)
{
var token = Request.QueryString["validationToken"];
return(Content(token, "plain/text"));
}
// Parse the received notifications.
else
{
try
{
var notifications = new Dictionary <string, Notification>();
using (var inputStream = new System.IO.StreamReader(Request.InputStream))
{
JObject jsonObject = JObject.Parse(inputStream.ReadToEnd());
if (jsonObject != null)
{
// Notifications are sent in a 'value' array. The array might contain multiple notifications for events that are
// registered for the same notification endpoint, and that occur within a short timespan.
JArray value = JArray.Parse(jsonObject["value"].ToString());
foreach (var notification in value)
{
Notification current = JsonConvert.DeserializeObject <Notification>(notification.ToString());
// Check client state to verify the message is from Microsoft Graph.
var subscription = SubscriptionCache.GetSubscriptionCache().GetSubscriptionInfo(current.SubscriptionId);
// This sample only works with subscriptions that are still cached.
if (subscription != null)
{
if (current.ClientState == subscription.ClientState)
{
// Just keep the latest notification for each resource.
// No point pulling data more than once.
notifications[current.Resource] = current;
}
}
}
if (notifications.Count > 0)
{
// Query for the changed messages.
await GetChangedMessagesAsync(notifications.Values);
}
}
}
}
catch (Exception)
{
// TODO: Handle the exception.
// Still return a 202 so the service doesn't resend the notification.
}
return(new HttpStatusCodeResult(202));
}
}
public async Task <ActionResult> DeleteSubscription()
{
string baseUrl = $"{Request.Url.Scheme}://{Request.Url.Authority}";
var subscriptions = SubscriptionCache.GetSubscriptionCache().DeleteAllSubscriptions();
try
{
foreach (var subscription in subscriptions)
{
await SubscriptionHelper.DeleteSubscription(subscription.Key, baseUrl);
}
return(RedirectToAction("SignOut", "Account"));
}
catch (Exception ex)
{
ViewBag.Message = BuildErrorMessage(ex);
return(View("Error", ex));
}
}
