Problem Description

When using flutter_workmanager on iOS, periodic tasks consistently receive inputData as null within the Workmanager().executeTask callback, despite being provided during registration. This issue is specific to iOS periodic tasks; Android periodic tasks and iOS one-off tasks function correctly.

Setup & Environment

• Prerequisites Confirmed:

  • README read
  • Android setup done
  • iOS setup done
  • Sample app tested, issue reproducible there.

• Workmanager Version: 0.7.0

• Xcode Version: 16.1

• Swift Version: 6.0.2

• iOS Deployment Target: 18.1

Steps Taken & Observed Behavior

1. iOS AppDelegate.swift Registration:
   A periodic task with identifier "my_task_name" is registered in AppDelegate.swift:

   WorkmanagerPlugin.registerPeriodicTask(withIdentifier: "my_task_name", frequency: NSNumber(value: 20 * 60))

2. Info.plist Configuration:
   The task identifier "my_task_name" is added to Info.plist, and background processing and fetching capabilities are enabled.
3. Flutter callbackDispatcher Task Registration:
   Inside the Workmanager().executeTask callback (which is triggered for the periodic task), the task is re-registered on the Flutter side with inputData:

   await Workmanager().registerPeriodicTask(
     "my_task_name",
     "my_task_name",
     frequency: const Duration(minutes: 20),
     initialDelay: const Duration(seconds: 30),
     existingWorkPolicy: ExistingWorkPolicy.replace,
     inputData: periodicAction.toInputData(), // periodicAction.toInputData() is confirmed to provide non-null data
     constraints: Constraints(networkType: NetworkType.connected),
   );

4. Issue: When the periodic task executes on iOS, the inputData received in the Dart executeTask callback is always null.
5. Suspected Cause: It's suspected that all executed periodic tasks originate from the initial iOS-side registration call, and subsequent registerPeriodicTask calls from the Flutter side (which provide inputData and other constraints) do not override or influence these tasks, even though logs indicate successful Flutter-side registration.

Relevant Logs & Diagnostics

• Task Registration Logs (Example):

  BGAppRefreshTask submitted my_task_name earliestBeginInSeconds:30.0
  flutter: Registered periodic task "my_task_name" for widget 5 (storm_map)
  

• flutter doctor -v Output:

  [✓] Flutter (Channel stable, 3.27.3, on macOS 15.5 24F74 darwin-arm64, locale en-US)
  [✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
  [✓] Xcode - develop for iOS and macOS (Xcode 16.1)
  [✓] Chrome - develop for the web
  [✓] Android Studio (version 2024.3)