launchdarkly_flutter 0.4.0

This is an unofficial LaunchDarkly SDK for Flutter, for anyone willing to use LaunchDarkly in a Flutter app.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter/services.dart';
import 'package:launchdarkly_flutter/launchdarkly_flutter.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool _shouldShow = false;
  bool _listenerRegistered = false;
  Map<String, dynamic> _allFlags = {};
  bool _listenerAllFlagsRegistered = false;
  LaunchdarklyFlutter launchdarklyFlutter;

  String mobileKey = 'YOUR_MOBILE_KEY';
  String userId = 'USER_ID';
  String flagKey = 'FLAG_KEY';

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

  // Platform messages are asynchronous, so we initialize in an async method.
  Future<void> initPlatformState() async {
    // Platform messages may fail, so we use a try/catch PlatformException.

    launchdarklyFlutter = LaunchdarklyFlutter();

    try {
      await launchdarklyFlutter.init(mobileKey, userId);
    } on PlatformException {}
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('LaunchDarkly Plugin'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text('Should show: $_shouldShow\n'),
              RaisedButton(
                onPressed: () async {
                  _verifyFlag(flagKey);
                },
                child: Text('Verify'),
              ),
              RaisedButton(
                onPressed: () async {
                  if (_listenerRegistered) {
                    try {
                      setState(() {
                        _listenerRegistered = false;
                      });
                      await launchdarklyFlutter
                          .unregisterFeatureFlagListener(flagKey);
                    } on PlatformException {
                      setState(() {
                        _listenerRegistered = true;
                      });
                    }
                  } else {
                    try {
                      setState(() {
                        _listenerRegistered = true;
                      });
                      await launchdarklyFlutter.registerFeatureFlagListener(
                          flagKey, _verifyFlag);
                    } on PlatformException {
                      setState(() {
                        _listenerRegistered = false;
                      });
                    }
                  }
                },
                child: Text(_listenerRegistered
                    ? 'Unregister listener'
                    : 'Register listener'),
              ),
              SizedBox(height: 30.0,),
              RaisedButton(
                onPressed: () async {
                  _verifyAllFlags([]);
                },
                child: Text('Verify all flags'),
              ),
              RaisedButton(
                onPressed: () async {
                  if (_listenerAllFlagsRegistered) {
                    try {
                      setState(() {
                        _listenerAllFlagsRegistered = false;
                      });
                      await launchdarklyFlutter
                          .unregisterAllFlagsListener('allFlags');
                    } on PlatformException {
                      setState(() {
                        _listenerAllFlagsRegistered = true;
                      });
                    }
                  } else {
                    try {
                      setState(() {
                        _listenerAllFlagsRegistered = true;
                      });
                      await launchdarklyFlutter.registerAllFlagsListener('allFlags', _verifyAllFlags);
                    } on PlatformException {
                      setState(() {
                        _listenerAllFlagsRegistered = false;
                      });
                    }
                  }
                },
                child: Text(_listenerAllFlagsRegistered
                    ? 'Unregister All Flags listener'
                    : 'Register All Flags listener'),
              ),
              Text('All flags: $_allFlags\n'),
            ],
          ),
        ),
      ),
    );
  }

  void _verifyFlag(String flagKey) async {
    bool shouldShow;
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      shouldShow = await launchdarklyFlutter.boolVariation(flagKey, false);
    } on PlatformException {
      shouldShow = false;
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      _shouldShow = shouldShow;
    });
  }

  void _verifyAllFlags(List<String> flagKeys) async {
    Map<String, dynamic> allFlags;
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      allFlags = await launchdarklyFlutter.allFlags();
    } on PlatformException {
      allFlags = {};
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      _allFlags = allFlags;
    });
  }
}