How does Facebook Messenger clear push notifications from the lock screen if you’ve read them on desktop?

Question

When I receive a message on Facebook I get a push notification on a lock screen (iOS). Then I read this message on desktop. Right after that this push notification disappear

Answer 1

This is a new feature on iOS 7 called Silent Push Notification, its a multitasking feature.

What you will need:

1 - Register for Remote Notifications in didFinishLaunchingWithOptions:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    [[UIApplication sharedApplication] registerForRemoteNotificationTypes:
     (UIRemoteNotificationTypeNewsstandContentAvailability|
      UIRemoteNotificationTypeBadge |
      UIRemoteNotificationTypeSound |
      UIRemoteNotificationTypeAlert)];

}

2 - Implement following method in ApplicationDelegate:

   - (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
      handler(UIBackgroundFetchResultNewData);


    // Possibl Results:
//    typedef enum {
//        UIBackgroundFetchResultNewData, //Download success with new data
//        UIBackgroundFetchResultNoData,  //No data to download
//        UIBackgroundFetchResultFailed   //Downlod Failed
//    } UIBackgroundFetchResult;
}

3 - Set UIBackgroundModes inside Application info.plist:

> UIBackgroundModes 
>     remote-notification