Base example with using std net/http

package main

import (
	"fmt"
	"log"
	"net/http"

	socketio "github.com/googollee/go-socket.io"
)

func main() {
	server := socketio.NewServer(nil)
	
	server.OnConnect("/", func(s socketio.Conn) error {
		s.SetContext("")
		fmt.Println("connected:", s.ID())
		return nil
	})

	server.OnEvent("/", "notice", func(s socketio.Conn, msg string) {
		fmt.Println("notice:", msg)
		s.Emit("reply", "have "+msg)
	})

	server.OnEvent("/chat", "msg", func(s socketio.Conn, msg string) string {
		s.SetContext(msg)
		return "recv " + msg
	})

	server.OnEvent("/", "bye", func(s socketio.Conn) string {
		last := s.Context().(string)
		s.Emit("bye", last)
		s.Close()
		return last
	})

	server.OnError("/", func(s socketio.Conn, e error) {
		// server.Remove(s.ID())
		fmt.Println("meet error:", e)
	})

	server.OnDisconnect("/", func(s socketio.Conn, reason string) {
		// Add the Remove session id. Fixed the connection & mem leak
		server.Remove(s.ID())
		fmt.Println("closed", reason)
	})

	go server.Serve()
	defer server.Close()

	http.Handle("/socket.io/", server)
	http.Handle("/", http.FileServer(http.Dir("./asset")))
	log.Println("Serving at localhost:8000...")
	log.Fatal(http.ListenAndServe(":8000", nil))
}

How to use the client

This is still very beta code and should not be relied upon.

package main

import (
	...
	socketio "github.com/googollee/go-socket.io"
)

func main() {
	uri := "http://127.0.0.1:8000"

	client, _ := socketio.NewClient(uri, nil)

	// Handle an incoming event
	client.OnEvent("reply", func(s socketio.Conn, msg string) {
		log.Println("Receive Message /reply: ", "reply", msg)
	})

	client.Connect()
	client.Emit("notice", "hello")
	client.Close()
}

How to use Redis broadcast adapter

server := socketio.NewServer(nil)

_, err := server.Adapter(&socketio.RedisAdapterOptions{
    Addr:   "127.0.0.1:6379",
    Host:   "127.0.0.1",
    Port:   "6379",
    Prefix: "socket.io", 
    DB: 1,
})
if err != nil {
    log.Fatal("error:", err)
}

Acknowledgements in go-socket.io 1.X.X

See documentation about acknowledgements

Sending ACK with data from SERVER to CLIENT

• Client-side

 //using client-side socket.io-1.X.X.js
socket.emit('some:event', JSON.stringify(someData), function(data){
   console.log('ACK from server wtih data: ', data);
});

• Server-side

// The return type may vary depending on whether you will return
// In golang implementation of Socket.IO don't used callbacks for acknowledgement,
// but used return value, which wrapped into ack package and returned to the client's callback in JavaScript
server.On("some:event", func(msg string) string {
	return msg //Sending ack with data in msg back to client, using "return statement"
})

Sending ACK with data from CLIENT to SERVER

• Client-side

//using client-side socket.io-1.X.X.js
//last parameter of "on" handler is callback for sending ack to server with data or without data
socket.on('some:event', function (msg, sendAckCb) {
    //Sending ACK with data to server after receiving some:event from server
    sendAckCb(JSON.stringify(data)); // for example used serializing to JSON
}

• Server-side

//You can use Emit or BroadcastTo with last parameter as callback for handling ack from client
//Sending packet to room "room_name" and event "some:event"
server.BroadcastTo("room_name", "some:event", dataForClient, func (so socketio.Socket, data string) {
	log.Println("Client ACK with data: ", data)
})

// Or

server.Emit("some:event", dataForClient, func (so socketio.Socket, data string) {
	log.Println("Client ACK with data: ", data)
})

Broadcast to All connected Client

• Server-side

//Add all connected user to a room, in example? "bcast"
server.OnConnect("/", func(s socketio.Conn) error {
	s.SetContext("")
	fmt.Println("connected:", s.ID())
	s.Join("bcast")
	return nil
})

//Broadcast message to all connected user
server.BroadcastToRoom("", "bcast", "event:name", msg)

• Client-side

socket.on('some:event', function (msg) {
	console.log(msg);
});

Catch Disconnected reason

• Server-side

server.OnDisconnect("/", func(so socketio.Conn, reason string) {
  	log.Println("closed", reason)
})

Possible reasons:

Reason	Side	Description
client namespace disconnect	Client Side	Got disconnect packet from client