CODEWITHSUNDEEP
flutter
josef
josef

Reputation: 193

How to load multiple future in flutter

I'm creating a flutter application that needs to load email and theme from preferences settings. Loading email will check whether the user is authenticated while loading the theme will check whether the theme is light or dark mode. The problem I'm facing is that dark or light mode is getting applied after the interface has been created. I know that using the future builder can help solve this but I have no idea on how to use it in theme.dart file. Any help please.

theme.dart file

import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

CustomTheme customTheme = CustomTheme();

class CustomTheme extends ChangeNotifier {
  static bool isDarkTheme = false;

  ThemeData get currentTheme => isDarkTheme
      ? ThemeData(
          brightness: Brightness.dark,
          scaffoldBackgroundColor: Colors.grey.shade900,
          primaryColor: Colors.white,
          accentColor: Colors.blue,
          iconTheme: const IconThemeData(color: Colors.white, opacity: 0.8),
        )
      : ThemeData(
          brightness: Brightness.light,
          scaffoldBackgroundColor: Colors.white,
          primaryColor: Colors.black,
          accentColor: Colors.blue,
          iconTheme: const IconThemeData(color: Colors.black, opacity: 0.8),
          dividerColor: Colors.black12,
        );

  CustomTheme() {
    loadPrefs();
  }

  void toggleTheme() {
    isDarkTheme = !isDarkTheme;
    savePrefs();
    notifyListeners();
  }

  void savePrefs() async {
    SharedPreferences _prefs = await SharedPreferences.getInstance();
    _prefs.setBool('theme', isDarkTheme);
  }

  void loadPrefs() async {
    SharedPreferences _prefs = await SharedPreferences.getInstance();
    isDarkTheme = _prefs.getBool('theme') ?? false;
    notifyListeners();
  }
}

main.dart file

import 'package:chatapp/home.dart';
import 'package:chatapp/login.dart';
import 'package:chatapp/themes.dart';
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:shared_preferences/shared_preferences.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

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

class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
  Future<String> getSharedPrefs() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    String _email = prefs.getString('email') ?? '';
    return _email;
  }

  @override
  void initState() {
    super.initState();
    customTheme.addListener(() {
      setState(() {});
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: customTheme.currentTheme,
      home: FutureBuilder<String>(
        future: getSharedPrefs(),
        builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return Scaffold(
              body: Center(
                child: CircularProgressIndicator(),
              ),
            );
          } else if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.hasError) {
              return const Text('Error');
            } else if (snapshot.hasData && snapshot.data!.isNotEmpty) {
              return Home();
            } else {
              return Login();
            }
          } else {
            return Text('State: ${snapshot.connectionState}');
          }
        },
      ),
    );
  }
}

Upvotes: 0

Views: 648

Answers (1)

Ravindra S. Patil
Ravindra S. Patil

Reputation: 14785

Try below code hope its helpful to you.used Future.wait([]) method for that refer here

FutureBuilder(
          future: Future.wait([
            getSharedPrefs(),
            // call your extra future method here
          ]),
          builder:
 ),

Upvotes: 1

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