flutter_secure_storage 3.2.1

Flutter Secure Storage provides API to store data in secure storage. Keychain is used in iOS, KeyStore based solution is used in Android.

example/lib/main.dart

import 'dart:async';
import 'dart:math';

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

void main() {
  runApp(new MaterialApp(home: new ItemsWidget()));
}

class ItemsWidget extends StatefulWidget {
  @override
  _ItemsWidgetState createState() => new _ItemsWidgetState();
}

enum _Actions { deleteAll }
enum _ItemActions { delete, edit }

class _ItemsWidgetState extends State<ItemsWidget> {
  final _storage = new FlutterSecureStorage();

  List<_SecItem> _items = [];

  @override
  void initState() {
    super.initState();

    _readAll();
  }

  Future<Null> _readAll() async {
    final all = await _storage.readAll();
    setState(() {
      return _items = all.keys
          .map((key) => new _SecItem(key, all[key]))
          .toList(growable: false);
    });
  }

  void _deleteAll() async {
    await _storage.deleteAll();
    _readAll();
  }

  void _addNewItem() async {
    final String key = _randomValue();
    final String value = _randomValue();

    await _storage.write(key: key, value: value);
    _readAll();
  }

  @override
  Widget build(BuildContext context) => new Scaffold(
        appBar: new AppBar(
          title: new Text('Plugin example app'),
          actions: <Widget>[
            new IconButton(onPressed: _addNewItem, icon: new Icon(Icons.add)),
            new PopupMenuButton<_Actions>(
                onSelected: (action) {
                  switch (action) {
                    case _Actions.deleteAll:
                      _deleteAll();
                      break;
                  }
                },
                itemBuilder: (BuildContext context) =>
                    <PopupMenuEntry<_Actions>>[
                      new PopupMenuItem(
                        value: _Actions.deleteAll,
                        child: new Text('Delete all'),
                      ),
                    ])
          ],
        ),
        body: new ListView.builder(
          itemCount: _items.length,
          itemBuilder: (BuildContext context, int index) => new ListTile(
                trailing: new PopupMenuButton(
                    onSelected: (_ItemActions action) =>
                        _performAction(action, _items[index]),
                    itemBuilder: (BuildContext context) =>
                        <PopupMenuEntry<_ItemActions>>[
                          new PopupMenuItem(
                            value: _ItemActions.delete,
                            child: new Text('Delete'),
                          ),
                          new PopupMenuItem(
                            value: _ItemActions.edit,
                            child: new Text('Edit'),
                          ),
                        ]),
                title: new Text(_items[index].value),
                subtitle: new Text(_items[index].key),
              ),
        ),
      );

  Future<Null> _performAction(_ItemActions action, _SecItem item) async {
    switch (action) {
      case _ItemActions.delete:
        await _storage.delete(key: item.key);
        _readAll();

        break;
      case _ItemActions.edit:
        final result = await showDialog<String>(
            context: context,
            builder: (context) => new _EditItemWidget(item.value));
        if (result != null) {
          _storage.write(key: item.key, value: result);
          _readAll();
        }
        break;
    }
  }

  String _randomValue() {
    final rand = new Random();
    final codeUnits = new List.generate(20, (index) {
      return rand.nextInt(26) + 65;
    });

    return new String.fromCharCodes(codeUnits);
  }
}

class _EditItemWidget extends StatelessWidget {
  final TextEditingController _controller;

  _EditItemWidget(String text)
      : _controller = new TextEditingController(text: text);

  @override
  Widget build(BuildContext context) {
    return new AlertDialog(
      title: new Text('Edit item'),
      content: new TextField(
        controller: _controller,
        autofocus: true,
      ),
      actions: <Widget>[
        new FlatButton(
            onPressed: () => Navigator.of(context).pop(),
            child: new Text('Cancel')),
        new FlatButton(
            onPressed: () => Navigator.of(context).pop(_controller.text),
            child: new Text('Save')),
      ],
    );
  }
}

class _SecItem {
  final String key;
  final String value;

  _SecItem(this.key, this.value);
}