Flutter Community

State Persistence

pub package

Persist state across app launches. By default this library store state as a local JSON file called data.json in the applications data directory. You can change this filename by providing another storage mechanism.

If you do not want to store your persisted app state as a JSON file you can extend PersistedStateStorage and provide your own methods for saving and loading data. E.g shared_preferences or sqflite. For those of you that are ambitious you could even store your state on the web or even in Firebase.

Example

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

void main() => runApp(App());

class App extends StatefulWidget {
  @override
  _AppState createState() => _AppState();
}

class _AppState extends State<App> {
  TextEditingController _textController;

  @override
  Widget build(BuildContext context) {
    return PersistedAppState(
      storage: JsonFileStorage(),
      child: MaterialApp(
        title: 'Persistent TextField Example',
        theme: ThemeData(primarySwatch: Colors.indigo),
        home: Scaffold(
          appBar: AppBar(title: Text('Persistent TextField Example')),
          body: Container(
            padding: const EdgeInsets.all(32.0),
            alignment: Alignment.center,
            child: PersistedStateBuilder(
              builder: (BuildContext context, AsyncSnapshot<PersistedData> snapshot) {
                if (snapshot.hasData) {
                  if (_textController == null) {
                    _textController = TextEditingController(text: snapshot.data['text'] ?? '');
                  }
                  return TextField(
                    controller: _textController,
                    decoration: InputDecoration(
                      hintText: 'Enter some text',
                    ),
                    onChanged: (String value) => snapshot.data['text'] = value,
                  );
                } else {
                  return CircularProgressIndicator();
                }
              },
            ),
          ),
        ),
      ),
    );
  }
}

Libraries

state_persistence