clear shared preferences from myBackgroundMessageHandler

Question

I want to clear shared preferences when I send a FCM message and app is in background. Inside myBackgroundMessageHandler method I am calling a method to clear them.

static Future<dynamic> myBackgroundMessageHandler(
      Map<String, dynamic> message) {
     clearPreferences();
}

static void clearPreferences() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.clear();
}

I am getting the following error:

Unhandled Exception: MissingPluginException(No implementation found for method getAll on channel plugins.flutter.io/shared_preferences)

What if the app isn't on background? Does that still happens? — Miguel Ruivo
@MiguelRuivo no, I have the shared preferences issue only when app is in background, since myBackgroundMessageHandler will not be called unless the app is in background — EddyG

Sin Hau Goh Sin Hau Goh · Accepted Answer · 2020-12-04T10:08:52

step 1) go to Application.kt/Application.java (in my case is kotlin)

step 2) add these line into Application class (in kotlin)

if (!registry!!.hasPlugin("io.flutter.plugins.sharedpreferences")) {
  SharedPreferencesPlugin.registerWith(registry!!.registrarFor("io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin"));
}

remember import this as well

import io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin

step 3) run flutter clean -> flutter get -> uninstall your app

clear shared preferences from myBackgroundMessageHandler

3 Answers