Version info

Usage

Dart Server

import'package:socket_io/socket_io.dart';main() {// Dart servervar io=Server();var nsp= io.of('/some');  nsp.on('connection', (client) {print('connection /some');    client.on('msg', (data) {print('data from /some => $data');      client.emit('fromServer',"ok 2");    });  });  io.on('connection', (client) {print('connection default namespace');    client.on('msg', (data) {print('data from default => $data');      client.emit('fromServer',"ok");    });  });  io.listen(3000);}

Dart Client

import'package:socket_io_client/socket_io_client.dart'as IO;main() {// Dart clientIO.Socket socket=IO.io('http://localhost:3000');  socket.onConnect((_) {print('connect');    socket.emit('msg','test');  });  socket.on('event', (data)=>print(data));  socket.onDisconnect((_)=>print('disconnect'));  socket.on('fromServer', (_)=>print(_));}

Connect manually

Update the extra headers

Socket socket= ...// Create socket.socket.io.options['extraHeaders']= {'foo':'bar'};// Update the extra headers.socket.io..disconnect()..connect();// Reconnect the socket manually.

Emit with acknowledgement

Socket socket= ...// Create socket.socket.onConnect((_) {print('connect');    socket.emitWithAck('msg','init', ack: (data) {print('ack $data') ;if (data!=null) {print('from server $data');        }else {print("Null") ;        }    });});

Socket connection events

constListEVENTS= ['connect','connect_error','disconnect','error','reconnect','reconnect_attempt','reconnect_failed','reconnect_error','ping','pong'];// Replace 'onConnect' with any of the above events.socket.onConnect((_) {print('connect');});

Acknowledge with the socket server that an event has been received

socket.on('eventName', (data) {final dataList= dataasList;final ack= dataList.lastasFunction;ack(null);});

Usage (Flutter)

IO.Socket socket=IO.io('http://localhost:3000',OptionBuilder()      .setTransports(['websocket'])// for Flutter or Dart VM      .setExtraHeaders({'foo':'bar'})// optional      .build());

Usage with stream and StreamBuilder in Flutter

import'dart:async';// STEP1:  Stream setupclassStreamSocket{final _socketResponse=StreamController<String>();voidFunction(String)get addResponse=> _socketResponse.sink.add;Stream<String>get getResponse=> _socketResponse.stream;voiddispose(){    _socketResponse.close();  }}StreamSocket streamSocket=StreamSocket();//STEP2: Add this function in main function in main.dart file and add incoming data to the streamvoidconnectAndListen(){IO.Socket socket=IO.io('http://localhost:3000',OptionBuilder()       .setTransports(['websocket']).build());    socket.onConnect((_) {print('connect');     socket.emit('msg','test');    });//When an event received from server, data is added to the stream    socket.on('event', (data)=> streamSocket.addResponse);    socket.onDisconnect((_)=>print('disconnect'));}//Step3: Build widgets with StreamBuilderclassBuildWithSocketStreamextendsStatelessWidget {constBuildWithSocketStream({Key key}):super(key: key);@overrideWidgetbuild(BuildContext context) {returnContainer(      child:StreamBuilder(        stream: streamSocket.getResponse ,        builder: (BuildContext context,AsyncSnapshot<String> snapshot){returnContainer(            child: snapshot.data,          );        },      ),    );  }}

Important Notice: Handling Socket Cache and subsequent lookups

Lookup protocol

Examples

_socket= io.io(        host,        io.OptionBuilder()            .setTransports(['websocket'])            .setExtraHeaders({'id': userId,'name': username})            .disableAutoConnect()            .enableReconnection()            .build());

Troubleshooting

Cannot connect "https" server or self-signed certificate server

classMyHttpOverridesextendsHttpOverrides {@overrideHttpClientcreateHttpClient(SecurityContext? context) {returnsuper.createHttpClient(context)      ..badCertificateCallback=          (X509Certificate cert,String host,int port)=>true;  }}voidmain() {HttpOverrides.global=MyHttpOverrides();runApp(MyApp());}

Memory leak issues in iOS when closing socket

Connect_error on MacOS with SocketException: Connection failed

<key>com.apple.security.network.client</key><true/>

Can't connect socket server on Flutter with Insecure HTTP connection

Notes to Contributors

Fork socket.io-client-dart

Who Uses

Socket.io Dart Server

Contributors