packages/shared_preferences/README.md

# Shared preferences plugin

[![pub package](https://img.shields.io/pub/v/shared_preferences.svg)](https://pub.dartlang.org/packages/shared_preferences)

Wraps NSUserDefaults (on iOS) and SharedPreferences (on Android), providing
a persistent store for simple data. Data is persisted to disk automatically
and asynchronously.

## Usage
To use this plugin, add `shared_preferences` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/).

### Example

``` dart
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

void main() {
  runApp(new MaterialApp(
    home: new Scaffold(
      body: new Center(
      child: new RaisedButton(
        onPressed: _incrementCounter,
        child: new Text('Increment Counter'),
        ),
      ),
    ),
  ));
}

_incrementCounter() async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  int counter = (prefs.getInt('counter') ?? 0) + 1;
  print('Pressed $counter times.');
  prefs.setInt('counter', counter);
}
```

### Testing

You can populate `SharedPreferences` with initial values in your tests by running this code:

```
const MethodChannel('plugins.flutter.io/shared_preferences')
  .setMockMethodCallHandler((MethodCall methodCall) async {
    if (methodCall.method == 'getAll') {
      return <String, dynamic>{}; // set initial values here if desired
    }
    return null;
  });
```