How to store data in shared preference when retrieve from database firestore in flutter?

Question

In my code at the home page fetch user name from firestore database and that's display nicely in UI. I want pass that name to shared preference function and store there and use that name in another pages also.

Code

home page code ( initstate and send name to saveNameToSharedPreferences() method )

  @override
  void initState() {
    super.initState();
    getData();
    fetchName();
    storeName();
  }

  void storeName() {
    String displayName = '${user?.displayName}';
    return displayName.saveNameToSharedPreferences();
  }

SharedPreferences code

import 'package:shared_preferences/shared_preferences.dart';

String? _displayName;

String? get displayName => _displayName;

Future saveNameToSharedPreferences() async {
  final SharedPreferences sn = await SharedPreferences.getInstance();

  await sn.setString('displayName', _displayName!);
}

Future getNameFromSharedPreferences() async {
  final SharedPreferences sn = await SharedPreferences.getInstance();

  _displayName = sn.getString('displayName');
}

How to solve this ?

Answer 1

You are calling function as an extension. Try to pass parameter instead.

Make the following changes

Future saveNameToSharedPreferences(String displayName) async {
  final SharedPreferences sn = await SharedPreferences.getInstance();

  await sn.setString('displayName', displayName);
}

And call it as

 void storeName() {
    String displayName = '${user?.displayName}';
    saveNameToSharedPreferences(displayName);
  }