How to run workmanager every 15 minutes in the background in flutter IOS

Question

I am working on adding a workmanager flutter to my project. Now it works perfectly on Android system as follows:

const fetchBackground = "fetchBackground";

void callbackDispatcher() {
  Workmanager.executeTask((task, inputData) async {
    switch (task) {
      case fetchBackground:
        Position userLocation = await Geolocator().getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
        notif.Notification notification = new notif.Notification();
        notification.showNotificationWithoutSound(userLocation);
        break;
    }
    return Future.value(true);
  });
}



void main() => runApp(MyApp());

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(

        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}
class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  @override
  void initState() {
    super.initState();

    Workmanager.initialize(
      callbackDispatcher,
      isInDebugMode: true,
    );


    Workmanager.registerPeriodicTask(
      "1",
      fetchBackground,
      frequency: Duration(minutes: 15),
    );
  }

So now every 15 minutes, the application will run in the background in the following and send an alert to the user that's perfect. But with IOS I cannot use: registerPeriodicTask.

Workmanager.registerPeriodicTask(
      "1",
      fetchBackground,
      frequency: Duration(minutes: 15),
    );

In this case, the app works for me without using registerPeriodicTask, but I have to run Debug → Simulate Background Fetch manually in order to get the alert from XCode. So what is the solution to make the app run every 15 minutes in the background in iOS as well as Android

Answer 1

So instead of this you can use the ansyns timer that will be called after every 15 seconds if the app is running no matter what screen is currently opened.

So you can call it in the main.dart file

Timer timerObj;
    timerObj = Timer.periodic(Duration(seconds: 15), (timer) async {
          _initData();
         
          }
        });
    
    In order to cancel the timer you can call timerObj = null or timerObj.cancel();

Answer 2

For Executing background fetch in iOS just add this line inside didFinishLaunchingWithOptions inside AppDelegate.swift UIApplication.shared.setMinimumBackgroundFetchInterval(TimeInterval(60*15))

For Ref: https://github.com/fluttercommunity/flutter_workmanager/blob/master/IOS_SETUP.md