import 'package:demo_app/services/api.dart';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

class AuthProvider extends ChangeNotifier{
  bool isAuthenticated = false;
  late String token;
  late ApiService apiService;

  AuthProvider() {
    init();
  }

  Future<void> init() async {
    token = await getToken();
    if (token.isNotEmpty) {
      isAuthenticated = true;
    }
    apiService = ApiService(token);
    notifyListeners();
  }

  Future<void> register(String name, String email, String password, String passwordConfirm, String deviceName) async{
  token = await apiService.register(name, email, password, passwordConfirm, deviceName);
  isAuthenticated = true;
  setToken();
  notifyListeners();
  }

  Future<void> logIn(String email, String password, String deviceName) async{
  token = await apiService.login(email, password, deviceName);
  isAuthenticated = true;
  setToken();    
  notifyListeners();
  }

  Future<void> logOut() async{
  token = '';
  isAuthenticated = false;
  setToken();  
  notifyListeners();
  }

  Future<void> setToken() async{
    final pref = await SharedPreferences.getInstance();
    pref.setString('token', token);
  }

  Future<void> getToken() async{
    final pref = await SharedPreferences.getInstance();
    pref.getString('token') ?? '';
  }

}

token = await getToken();

gives this error

This expression has a type of 'void' so its value can't be used. Try checking to see if you're using the correct API; there might be a function or call that returns void you didn't expect. Also check type parameters and variables which might also be void.

Any clue on solving this issue?

CodePudding user response：

Try the following code:

Future<void> init() async {
  token = await getToken();
  if (token.isNotEmpty) {
    isAuthenticated = true;
  }
  apiService = ApiService(token);
  notifyListeners();
}

Future<String> getToken() async {
  final pref = await SharedPreferences.getInstance();
  final token = pref.getString("token") ?? "";
  return token;
}