I have connected firebase login to my test app and want to use local authentication there. I have seen many examples that are based on local_auth package but they only show how to authenticate locally, but I wanted to use email and password after authenticating .
for more clrity, I read a post from medium where it says:
** When a user after first sign-in/signup decides to activate authentication using the above methods, he/she practically says save my login credentials in a local host where nobody without a registered fingerprint and face ID can access. So when the users come into login and decide to use this method it basically fetches the login credentials from where it was locally stored. **
But how can I implement this in flutter?
CodePudding user response：
You need to Store Your Credentials Like this Example . Kindly Have a Look
dependencies:
flutter_secure_storage: ^5.0.2
import 'dart:async';
import 'dart:io';
import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
void main() {
runApp(const MaterialApp(home: ItemsWidget()));
}
class ItemsWidget extends StatefulWidget {
const ItemsWidget({Key? key}) : super(key: key);
@override
_ItemsWidgetState createState() => _ItemsWidgetState();
}
enum _Actions { deleteAll }
enum _ItemActions { delete, edit, containsKey }
class _ItemsWidgetState extends State<ItemsWidget> {
final _storage = const FlutterSecureStorage();
final _accountNameController =
TextEditingController(text: 'flutter_secure_storage_service');
List<_SecItem> _items = [];
@override
void initState() {
super.initState();
_accountNameController.addListener(() => _readAll());
_readAll();
}
Future<void> _readAll() async {
final all = await _storage.readAll(
iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
setState(() {
_items = all.entries
.map((entry) => _SecItem(entry.key, entry.value))
.toList(growable: false);
});
}
void _deleteAll() async {
await _storage.deleteAll(
iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
_readAll();
}
void _addNewItem() async {
final String key = _randomValue();
final String value = _randomValue();
await _storage.write(
key: key,
value: value,
iOptions: _getIOSOptions(),
aOptions: _getAndroidOptions());
_readAll();
}
IOSOptions _getIOSOptions() => IOSOptions(
accountName: _getAccountName(),
);
AndroidOptions _getAndroidOptions() => const AndroidOptions(
encryptedSharedPreferences: true,
);
String? _getAccountName() =>
_accountNameController.text.isEmpty ? null : _accountNameController.text;
@override
Widget build(BuildContext context) => Scaffold(
appBar: AppBar(
title: const Text('Plugin example app'),
actions: <Widget>[
IconButton(
key: const Key('add_random'),
onPressed: _addNewItem,
icon: const Icon(Icons.add)),
PopupMenuButton<_Actions>(
key: const Key('popup_menu'),
onSelected: (action) {
switch (action) {
case _Actions.deleteAll:
_deleteAll();
break;
}
},
itemBuilder: (BuildContext context) =>
<PopupMenuEntry<_Actions>>[
const PopupMenuItem(
key: Key('delete_all'),
value: _Actions.deleteAll,
child: Text('Delete all'),
),
])
],
),
body: Column(
children: [
if (!kIsWeb && Platform.isIOS)
Padding(
padding: const EdgeInsets.symmetric(horizontal: 16),
child: TextFormField(
controller: _accountNameController,
decoration:
const InputDecoration(labelText: 'kSecAttrService'),
),
),
Expanded(
child: ListView.builder(
itemCount: _items.length,
itemBuilder: (BuildContext context, int index) => ListTile(
trailing: PopupMenuButton(
key: Key('popup_row_$index'),
onSelected: (_ItemActions action) =>
_performAction(action, _items[index], context),
itemBuilder: (BuildContext context) =>
<PopupMenuEntry<_ItemActions>>[
PopupMenuItem(
value: _ItemActions.delete,
child: Text(
'Delete',
key: Key('delete_row_$index'),
),
),
PopupMenuItem(
value: _ItemActions.edit,
child: Text(
'Edit',
key: Key('edit_row_$index'),
),
),
PopupMenuItem(
value: _ItemActions.containsKey,
child: Text(
'Contains Key',
key: Key('contains_row_$index'),
),
),
]),
title: Text(
_items[index].value,
key: Key('title_row_$index'),
),
subtitle: Text(
_items[index].key,
key: Key('subtitle_row_$index'),
),
),
),
),
],
),
);
Future<void> _performAction(
_ItemActions action, _SecItem item, BuildContext context) async {
switch (action) {
case _ItemActions.delete:
await _storage.delete(
key: item.key,
iOptions: _getIOSOptions(),
aOptions: _getAndroidOptions());
_readAll();
break;
case _ItemActions.edit:
final result = await showDialog<String>(
context: context,
builder: (context) => _EditItemWidget(item.value));
if (result != null) {
await _storage.write(
key: item.key,
value: result,
iOptions: _getIOSOptions(),
aOptions: _getAndroidOptions());
_readAll();
}
break;
case _ItemActions.containsKey:
final result = await _storage.containsKey(key: item.key);
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text('Contains Key: $result'),
// backgroundColor: Colors.green,
duration: const Duration(seconds: 4),
));
break;
}
}
String _randomValue() {
final rand = Random();
final codeUnits = List.generate(20, (index) {
return rand.nextInt(26) 65;
});
return String.fromCharCodes(codeUnits);
}
}
class _EditItemWidget extends StatelessWidget {
_EditItemWidget(String text)
: _controller = TextEditingController(text: text);
final TextEditingController _controller;
@override
Widget build(BuildContext context) {
return AlertDialog(
title: const Text('Edit item'),
content: TextField(
key: const Key('title_field'),
controller: _controller,
autofocus: true,
),
actions: <Widget>[
TextButton(
key: const Key('cancel'),
onPressed: () => Navigator.of(context).pop(),
child: const Text('Cancel')),
TextButton(
key: const Key('save'),
onPressed: () => Navigator.of(context).pop(_controller.text),
child: const Text('Save')),
],
);
}
}
class _SecItem {
_SecItem(this.key, this.value);
final String key;
final String value;
}