chore(demos): remove shared preferences on logout (#180)

* chore(demos): remove sharedpreferences on logout

* chore: remove log

---------

Co-authored-by: DominicGBauer <[email protected]>

Author: DominicGBauer

demos/django-todolist/lib/api_client.dart

@@ -1,8 +1,5 @@
 import 'dart:convert';
 import 'package:http/http.dart' as http;
-import 'package:logging/logging.dart';
-
-final log = Logger('powersync-django-todolist');
 
 class ApiClient {
   final String baseUrl;

demos/django-todolist/lib/powersync.dart

@@ -11,6 +11,7 @@ import './app_config.dart';
 import './models/schema.dart';
 
 final log = Logger('powersync-django');
+final prefs = SharedPreferencesAsync();
 
 /// Postgres Response codes that we cannot recover from by retrying.
 final List<RegExp> fatalResponseCodes = [
@@ -89,8 +90,7 @@ bool _dbInitialized = false;
 
 /// id of the user currently logged in
 Future<String?> getUserId() async {
-  final prefs = await SharedPreferences.getInstance();
-  return prefs.getString('id');
+  return await prefs.getString('id');
 }
 
 Future<bool> isLoggedIn() async {
@@ -129,5 +129,6 @@ Future<void> openDatabase() async {
 
 /// Explicit sign out - clear database and log out.
 Future<void> logout() async {
+  await prefs.remove('id');
   await db.disconnectAndClear();
 }

demos/django-todolist/lib/widgets/login_page.dart

@@ -3,7 +3,6 @@ import 'package:flutter/material.dart';
 import 'package:powersync_django_todolist_demo/api_client.dart';
 import 'package:powersync_django_todolist_demo/app_config.dart';
 import 'package:powersync_django_todolist_demo/powersync.dart';
-import 'package:shared_preferences/shared_preferences.dart';
 
 import '../main.dart';
 
@@ -42,7 +41,6 @@ class _LoginPageState extends State<LoginPage> {
 
       final payload = _parseJwt(session['access_token']);
       if (payload.containsKey('sub')) {
-        final prefs = await SharedPreferences.getInstance();
         await prefs.setString('id', payload['sub'].toString());
 
         //re-init PowerSync manually for first time sign in