I want to get user details such as id, email, username in my HomePage when the user login into the login page. I was able to get the data via this

SPUtil.putString('user', user); print(user);

Now, the issue is how should I pick it up in another page for usage or display those data. I have a file called sputils.dart where all the code that I used to get the data.

class AuthService {
  Future<String> login({
    required String username,
    required String password,
  }) async {
    try {
      final body = {
        'username': username,
        'password': password,
      };

      final response = await http.post(
        Uri.parse('$BASE_URL/login'),
        headers: {'Content-Type': 'application/json; charset=UTF-8'},
        body: jsonEncode(body),
      );

      if (response.statusCode != 200) {
        throw LoginError.unexpected;
      }
      Map<String, dynamic> data = jsonDecode(response.body);
      User loggedInUser = User.fromJson(data['user']);
      String user = jsonEncode(loggedInUser);

      SPUtil.putString('user', user);
      print(user);
      return jsonDecode(response.body)['token'];
    } on LoginError {
      print('login error');
      rethrow;
    } catch (e) {
      print(e);
      throw LoginError.unexpected;
    }
  }





import 'dart:async';
import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:synchronized/synchronized.dart';

// SharedPreferences
class SPUtil {
  static SPUtil? _singleton;
  static SharedPreferences? _prefs;
  static final Lock _lock = Lock();

  static Future<SPUtil> getInstance() async {
    if (_singleton == null) {
      await _lock.synchronized(() async {
        if (_singleton == null) {
          // keep local instance till it is fully initialized.
          final singleton = SPUtil._();
          await singleton._init();
          _singleton = singleton;
        }
      });
    }
    return _singleton!;
  }

  SPUtil._();

  Future _init() async {
    _prefs = await SharedPreferences.getInstance();
  }

  // put object
  static Future<bool> putObject(String key, Object value) {
    return _prefs!.setString(key, json.encode(value));
  }

  // get string
  static String getString(String key, {String defValue = ''}) {
    if (_prefs == null) return defValue;
    return _prefs!.getString(key) ?? defValue;
  }

  // put string
  static Future<bool> putString(String key, String value) async {
    return _prefs!.setString(key, value);
  }

  // get bool
  static bool getBool(String key, {bool defValue = false}) {
    if (_prefs == null) return defValue;
    return _prefs!.getBool(key) ?? defValue;
  }

  // put bool
  static Future<bool> putBool(String key, {bool value = false}) {
    return _prefs!.setBool(key, value);
  }

  // get int
  static int getInt(String key, {int defValue = 0}) {
    if (_prefs == null) return defValue;
    return _prefs!.getInt(key) ?? defValue;
  }

  // put int.
  static Future<bool> putInt(String key, int value) {
    return _prefs!.setInt(key, value);
  }

  // get double
  static double getDouble(String key, {double defValue = 0.0}) {
    if (_prefs == null) return defValue;
    return _prefs!.getDouble(key) ?? defValue;
  }

  // put double
  static Future<bool> putDouble(String key, double value) {
    return _prefs!.setDouble(key, value);
  }

  // get string list
  static List<String> getStringList(String key,
      {List<String> defValue = const []}) {
    if (_prefs == null) return defValue;
    return _prefs!.getStringList(key) ?? defValue;
  }

  // put string list
  static Future<bool> putStringList(String key, List<String> value) {
    return _prefs!.setStringList(key, value);
  }

  // clear
  static Future<bool> clear() {
    return _prefs!.clear();
  }

  // clear a string
  static Future<bool> clearString(String key) {
    return _prefs!.remove(key);
  }

  //Sp is initialized
  static bool isInitialized() {
    return _prefs != null;
  }
}

CodePudding user response：

you can use https://pub.dev/packages/shared_preferences

easier to use bro hehe

CodePudding user response：

To use saved data from another page,

1. make your data instance to global(static)
2. save the data inside of static class

If your application is simple and just test something, go to No.1.

Or else, go to No.2.

• make class static : https://dev.to/lucianojung/global-variable-access-in-flutter-3ijm

• Using getController is easier to make it global : https://pub.dev/packages/get