Is there a way to run the code when sending a local notification?

Question

I want to run some code to update the viewcontroller when my local notification was sent, I tried the didReceiveLocalNotification function, but it only works when the user clicks on the notification, I was wondering, how does the function start when sending a notification?

Answer 1

I think that you cannot find out when your local notification is sent, mainly because you can schedule a local notification or send it right away if your application is in the background.

According to Apple :

You schedule a local notification by calling scheduleLocalNotification: The application uses the fire date specified in the UILocalNotification object at the time of delivery. Alternatively, you can immediately send a notification by calling the presentLocalNotificationNow: method.

Applications may also find that local notifications are useful when they run in the background, as well as some messages, data, or other items that may be of interest to the user. In this case, the application can immediately send a notification using the UIApplication presentLocalNotificationNow: method (iOS gives a limited time to run in the background).

It is not possible to know when the UILocalNotification was sent, but when it was received, this is of course the case. In your case, I assume that you are planning UILocalNotification , so share it in parts:

• A notification is delivered when the application is not open and the user touches it

  The delegate for the iOS application implements the application:didFinishLaunchingWithOptions: method to handle local notification. It obtains the associated UILocalNotification object from the startup parameter dictionary using the UIApplicationLaunchOptionsLocalNotificationKey key. Therefore, you can find out where the application was opened by touching UILocalNotification . See the following code:

   func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { if let launchNotification = launchOptions?[UIApplicationLaunchOptionsLocalNotificationKey] as? UILocalNotification { // do anything you want update UIViewController, etc } return true } 

• A notification is delivered when the application is launched and the user touches it

  Once the user touches UILocalNotification , you can process it using the didReceiveLocalNotification method and do whatever you want inside it.

• A notification is delivered when the application is running and the user does not touch it

If the user does not touch UILocalNotification , the only thing you can do to find out if your UILocalNotification been sent is to save the list with UILocalNotifications that you planned earlier and check it later (this is not a great solution, but its work).

However, there is always a UIApplicationWillEnterForegroundNotification that can be used to notify the UIViewController that you want to update so that the application comes to the forefront, as described below:

 private var foregroundNotification: NSObjectProtocol! override func viewDidLoad() { super.viewDidLoad() foregroundNotification = NSNotificationCenter.defaultCenter().addObserverForName(UIApplicationWillEnterForegroundNotification, object: nil, queue: NSOperationQueue.mainQueue()) { [unowned self] notification in print("Notified ViewControllerB") } } deinit { // make sure to remove the observer when this view controller is dismissed/deallocated NSNotificationCenter.defaultCenter().removeObserver(foregroundNotification) } 

I think that you need to think correctly what you need to do inside your application when your notification is received in case the user does not touch it.

Hope this helps you.

Answer 2

There is a method for this in object c, you can look for something like this for fast. Add this method to your appdelegate

 - (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions UNNotificationPresentationOptionBadge))completionHandler{ [self.tableview reloadData]; } 

I think this will help ..

Answer 3

You can make your updates from the method that you use to send a notification.