Wsrtjtyk

I have a simple app that updates a UILabel when the user taps on a local push notification. In the simulator when I tap on the notification, applicationDidBecomeActive gets called and in that, I have a shared object referring to the view controller class. Then I call the function in that class that get a new string and sets the UILabel to said string.

This works all the time in the simulator but when I load the app onto my device it works the first couple of times and then stops.

I know the device is updating the string value because when I swap to another view in the app and switch back the UILabel now shows the correctly updated value but not when coming back from a notification.

Has anyone else had this problem where the simulator and physical device behave differently?

As requested here is some code that hopefully helps:

This is from the appDelagate.swift file

func applicationDidBecomeActive(_ application: UIApplication) {

    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

    fetchCurrentUnQuoteFromViewController()

    print("applicationDidBecomeActive has finished running.")

}



//Custom functions for the delagate

func setDefaultToTrue() {

    readyForNewUnQuote = true

    defaults.setValue(readyForNewUnQuote, forKey: "readyForNewUnQuote")

}



func fetchCurrentUnQuoteFromViewController() {

    let quoteViewController:QuoteViewController = window!.rootViewController as! QuoteViewController

    quoteViewController.getRandomGradient()

    quoteViewController.fetchRandomUnQuote()

}

In my view controller here are the functions that are called from the appDelagate

func getRandomGradient() {

    let randomNumber: Int = Int.random(in: 0 ... gradientArray.count - 1)

    QuoteGradient.image = UIImage(named: gradientArray[randomNumber])

}



func updateUI() {

    unQuoteLabel.text = defaults.string(forKey: "currentQuote")

}

Edit: I have basically added viewController.viewDidLoad() as an extra call and that seems to be working. Is this a bad call to make? It seems like a hackish way to fix things.

Ok, I think I've narrowed it down even further. I have a second view which I am trying to use for a settings page. If I just keep on the first view with the quote text then when a notification pops up I can tap it and it will update to the new text that is set.

However, if I go to the settings view and then back to the quote view then when I tap on a notification it doesn't update the text until I go back to the settings page and then back to the quote page again.

I am pretty new to iOS development and don't really know if going to the new view does anything to the shared object I am creating or if it does something else I am not aware of.

Edit 2: Here is the function that fires when a user taps on a notification:

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

    setDefaultToTrue()

    print(defaults.value(forKey: "readyForNewUnQuote") ?? "Error")



    fetchCurrentUnQuoteFromViewController()



    print("response from notification was fired.")



    completionHandler()

}

Give this a go. I have not used local notifications in a while but it appears you can check the delegate for the notification center for a acceptance of the alert.

import UIKit

import UserNotifications



@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate {



    var window: UIWindow?



    let handler = NotificationHandler()

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        handler.appDelegate = self

        let center = UNUserNotificationCenter.current()

        center.delegate = handler

        return true

    }



    func applicationDidBecomeActive(_ application: UIApplication) {

        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.



    }

}



class NotificationHandler: NSObject, UNUserNotificationCenterDelegate {

    var appDelegate : AppDelegate?

    func userNotificationCenter(_ center: UNUserNotificationCenter,

                                willPresent notification: UNNotification,

                                withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

        // Play sound and show alert to the user

        completionHandler([.alert,.sound])

    }



    func userNotificationCenter(_ center: UNUserNotificationCenter,

                                didReceive response: UNNotificationResponse,

                                withCompletionHandler completionHandler: @escaping () -> Void) {



        switch response.actionIdentifier {

        case UNNotificationDismissActionIdentifier:

            print("Dismiss Action")

        case UNNotificationDefaultActionIdentifier:

            print("we are launching")

            if let app = appDelegate,

                let root = app.window?.rootViewController as? ViewController{

                print("we have the info")

                root.titleLabel.text = response.notification.request.content.title

                root.bodyLabel.text = response.notification.request.content.body

            }

        case "Snooze":

            print("Snooze")

        case "Delete":

            print("Delete")

        default:

            print("Unknown action")

        }

        completionHandler()

    }

}





import UIKit

import UserNotifications



class ViewController: UIViewController {



    let center = UNUserNotificationCenter.current()



    lazy var titleLabel : UILabel = {

        let lbl = UILabel(frame: CGRect(x: 20, y: 0, width: self.view.bounds.width - 40, height: 50))

        lbl.textColor = .black

        lbl.font = UIFont.systemFont(ofSize: 20)

        lbl.numberOfLines = 0

        lbl.textAlignment = .center

        return lbl

    }()



    lazy var bodyLabel : UILabel = {

        let lbl = UILabel(frame: CGRect(x: 20, y: titleLabel.frame.maxY, width: self.view.bounds.width - 40, height: 50))

        lbl.textColor = .black

        lbl.font = UIFont.systemFont(ofSize: 20)

        lbl.numberOfLines = 0

        lbl.textAlignment = .center

        return lbl

    }()





    override func viewDidLoad() {

        super.viewDidLoad()



        self.view.addSubview(titleLabel)

        titleLabel.center = self.view.center

        titleLabel.text = "We are just getting started"

        self.view.addSubview(bodyLabel)



        let options: UNAuthorizationOptions = [.alert, .sound]

        center.requestAuthorization(options: options) {

            (granted, error) in

            if !granted {

                print("Something went wrong")

            }

        }



        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2.0) {

            self.center.removeAllDeliveredNotifications()

            self.center.removeAllPendingNotificationRequests()

            self.setNotificationWith(title: "Party", contentBody: "Party like it's 1999")

        }

    }



    func setNotificationWith(title:String,contentBody:String){

        let content = UNMutableNotificationContent()

        content.title = title

        content.body = contentBody

        content.sound = UNNotificationSound.default



        let date = Date(timeIntervalSinceNow: 60)

        let triggerDate = Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second,], from: date)



        let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDate,

                                                    repeats: false)



        let identifier = "NotificationTest"

        let request = UNNotificationRequest(identifier: identifier,

                                            content: content, trigger: trigger)

        center.add(request, withCompletionHandler: { (error) in

            if let error = error {

                // Something went wrong

                print("we have an error (error)")

            }

        })

    }

}

I have solved my problem! The issue was with the segues I was using in the storyboard.

Instead of using visual segues I changed it so that when I press the settings button I run this function here which loads in a view from the storyboard and then presents it to the user. Then I have another button on the settings page that dismisses the page.

@IBAction func settingsButtonAction(_ sender: UIButton) {

    let controller = storyboard?.instantiateViewController(withIdentifier: "SettingsViewController") as! SettingsViewController

    present(controller, animated: true, completion: nil)

}

I have no idea why this was causing the issue as I am still new to swift and iOS development but from now on I won't be using the storyboard to present different views to the user. I will only be using the present and dismiss functions for now.