Flutter trên iOS, Android và web

flutter pub add dart_pusher_channels

// lib/realtime.dart
import 'package:dart_pusher_channels/dart_pusher_channels.dart';

final realtime = PusherChannelsClient.websocket(
  options: PusherChannelsOptions.fromHost(
    scheme: 'wss',
    host: 'ws.hibira.io',
    port: 443,
    key: const String.fromEnvironment('HIBIRA_KEY'),
  ),
  connectionErrorHandler: (error, trace, refresh) => refresh(),
);

// lib/order_screen.dart
import 'dart:async';
import 'package:dart_pusher_channels/dart_pusher_channels.dart';
import 'package:flutter/material.dart';
import 'realtime.dart';

class OrderScreen extends StatefulWidget {
  const OrderScreen({super.key, required this.orderId, required this.token});
  final String orderId;
  final String token;

  @override
  State<OrderScreen> createState() => _OrderScreenState();
}

class _OrderScreenState extends State<OrderScreen> {
  late final PrivateChannel channel;
  final subs = <StreamSubscription>[];
  String status = '…';

  @override
  void initState() {
    super.initState();
    channel = realtime.privateChannel(
      'private-order-${widget.orderId}',
      authorizationDelegate: EndpointAuthorizableChannelTokenAuthorizationDelegate.forPrivateChannel(
        authorizationEndpoint: Uri.parse('https://api.example.com/pusher/auth'),
        headers: {'Authorization': 'Bearer ${widget.token}'},
      ),
    );
    subs.add(channel.bind('status').listen((event) {
      setState(() => status = event.tryGetDataAsMap()?['status'] ?? status);
    }));
    subs.add(realtime.onConnectionEstablished.listen((_) => channel.subscribeIfNotUnsubscribed()));
    channel.subscribeIfNotUnsubscribed();
  }

  @override
  void dispose() {
    for (final s in subs) {
      s.cancel();
    }
    channel.unsubscribe();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => Text(status);
}

class _AppState extends State<App> with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    realtime.connect();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.paused) realtime.disconnect();
    if (state == AppLifecycleState.resumed) realtime.connect();
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => const MaterialApp(home: HomeScreen());
}