talkUserCheckFlutter.dart

// Android HTTP 설정
// - Manifest : 
// (1) <uses-permission android:name="android.permission.INTERNET" />
// (2) <application
//        android:label="exmaplee"
//        android:icon="@mipmap/ic_launcher"
//       android:usesCleartextTraffic="true">

// IOS HTTP 설정
// - Info.plist
//  <key>NSAppTransportSecurity</key>
//	<dict>
//		<key>NSAllowsArbitraryLoads</key>
//		<true/>
//	</dict>

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:socket_io_client/socket_io_client.dart' as IO;

void main() => runApp(MaterialApp(home: Login(),));

// ignore: must_be_immutable
class Login extends StatelessWidget {
  TextEditingController controller = new TextEditingController(text: "");
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('로그인 '),),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.login),
        onPressed: () async{
          if(this.controller.text.isEmpty) return null;
          http.Response res = await http.get('http://127.0.0.1:3003/login?id=${this.controller.text}');
          bool check = json.decode(res.body);
          if(!check){
            await showDialog<void>(
              context: context,
              builder: (BuildContext context) => AlertDialog(
                title: Text("로그인 실패"),
                actions: [TextButton(child: Text("닫기"),onPressed: () => Navigator.of(context).pop<void>(),)],
              ),
            );
            this.controller.text = "";
            return;
          }
          await Navigator.of(context).push(
            MaterialPageRoute<void>(builder: (BuildContext context) => MyApp(id: controller.text)),
          );
          this.controller.text = "";
          return;
        },
      ),
      body: Center(
        child: Container(
          margin: EdgeInsets.all(20.0),
          child: TextField(controller: controller,),
        ),
      ),
    );
  }
}

// ignore: must_be_immutable
class MyApp extends StatefulWidget {
  String id;
  MyApp({@required this.id});
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {

  List fds;
  String serverURL = "http://127.0.0.1:3003";

  IO.Socket socket = IO.io("http://127.0.0.1/",<String, dynamic>{
    'transports': ['websocket'],
    'autoConnect': false,
  });
  @override
  void initState() {

    Future.microtask(() async{
      socket..connect()..on('userEvent', (data){
          Future.microtask(() async{
            http.Response res = await http.get("$serverURL/fds?id=${widget.id}");
            fds = json.decode(res.body);
            if(!mounted) return;
            setState(() {});
          });
        });
      http.Response res = await http.get("$serverURL/fds?id=${widget.id}");
      fds = json.decode(res.body);
      if(!mounted) return;
      setState(() {});
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("안녕하세요 ${widget.id} 님"),),
      body: this.fds == null
        ? Center(child: Text("로딩중"),)
        : ListView.builder(
          itemCount: this.fds.length,
          itemBuilder: (BuildContext context, int index){
            return ListTile(
              leading: CircleAvatar(
                child: Container(
                  decoration: BoxDecoration(
                    color: this.fds[index]['on'] ? Colors.blue : Colors.grey
                  ),
                ),
              ),
              title: Text(this.fds[index]['name'].toString()),
              subtitle: Text("상태명"),
              trailing: Icon(Icons.call),
            );
          }
        ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.send),
        onPressed: () async{
          http.Response res = await http.get('$serverURL/logout?id=${widget.id}');
          bool check = json.decode(res.body);
          if(!check) return print("로그아웃 실패");
          socket.emit("userLogout", "data");
          return Navigator.of(context).pop<void>();
        },
      ),
    );
  }
}