🐞PlatformException "You have not properly initialized the Flutter WorkManager Package" on first run

[jonathanduke]

Description

After upgrading to the 0.9.0+2 version of the package, I am getting an exception when registering any task after calling initialize(), but it incorrectly claims that I have not called initialize(). I eventually determined that this only occurs on the first run of the application (or the first run after upgrading to this particular version of the plugin).

Unsuccessful Workarounds

• I added a delayed timer to wait 60 seconds before calling registerPeriodicTask after calling initialize to rule out any race conditions, but the exception persisted.
• I tried catching and retrying registerPeriodicTask over a period of time to see if it would succeed after additional attempts, but it failed every time.
• I tried calling initialize() twice, but it still did not fix the issue.
• The only "fix" was relaunching the app, so the exception seemed to be limited to the first run only.

Steps to Reproduce

• In your main() method, call await Workmanager().initialize(yourEntryMethod);
• On the next line, call await Workmanager().registerPeriodicTask("testTask", "testTask");
• Uninstall or wipe user data on your existing app, if installed.
• Rebuild and run. You should see the exception on the first run.
• Close the app and run again. The exception should not appear.

Error

PlatformException(Exception, java.lang.Exception: You have not properly initialized the Flutter WorkManager Package. You should ensure you have called the 'initialize' function first!, Cause: null, Stacktrace: java.lang.Exception: You have not properly initialized the Flutter WorkManager Package. You should ensure you have called the 'initialize' function first!
	at dev.fluttercommunity.workmanager.WorkmanagerPlugin.registerPeriodicTask(WorkmanagerPlugin.kt:79)
	at dev.fluttercommunity.workmanager.pigeon.WorkmanagerHostApi$Companion.setUp$lambda$9$lambda$8(WorkmanagerApi.g.kt:700)
	at dev.fluttercommunity.workmanager.pigeon.WorkmanagerHostApi$Companion.$r8$lambda$idyf-0kIY8_7C_5YHaSad8xqwzo(Unknown Source:0)
	at dev.fluttercommunity.workmanager.pigeon.WorkmanagerHostApi$Companion$$ExternalSyntheticLambda16.onMessage(D8$$SyntheticClass:0)
	at io.flutter.plugin.common.BasicMessageChannel$IncomingMessageHandler.onMessage(BasicMessageChannel.java:261)
	at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:292)
	at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$io-flutter-embedding-engine-dart-DartMessenger(DartMessenger.java:319)
	at io.flutter.embedding.engine.dart.DartMessenger$$ExternalSyntheticLambda0.run(D8$$SyntheticClass:0)
	at android.os.Handler.handleCallback(Handler.java:883)
	at android.os.Handler.dispatchMessage(Handler.java:100)
	at android.os.Looper.loop(Looper.java:214)
	at android.app.ActivityThread.main(ActivityThread.java:7356)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
, null)
       at WorkmanagerHostApi.registerPeriodicTask(workmanager_api.g.dart:700)
       at WorkmanagerAndroid.registerPeriodicTask(workmanager_android.dart:75)

Solution

This appears to be a bug in WorkmanagerPlugin.kt that updates the handle in SharedPrefs but does not update the local variable upon initialization. I am currently testing a PR to fix that scenario.

[jonathanduke]

Until PR #646 is merged and published, I have updated my package.json to reference my fork as follows:

dependency_overrides:
  workmanager_android:
    git:
      url: https://github.com/jonathanduke/flutter_workmanager.git
      ref: fix-645
      path: workmanager_android

I no longer get the exception on the first launch, and I can see that the task is successfully scheduled:

D/WM-SystemJobScheduler(26148): Scheduling work ID 667bd190-4952-47b2-8ea8-7dd3d72f7acdJob ID 0
D/WM-PackageManagerHelper(26148): androidx.work.impl.background.systemalarm.RescheduleReceiver enabled

[Muneeza-PT]

I am also facing same issue on the first run of the application.