socket.io

Install

go get github.com/googollee/go-socket.io

import "github.com/googollee/go-socket.io"

Example

package main
import (
	"log"
	"net/http"
	"github.com/googollee/go-socket.io"
)
func main() {
	server, err := socketio.NewServer(nil)
	if err != nil {
		log.Fatal(err)
	}
	server.On("connection", func(so socketio.Socket) {
		log.Println("on connection")
		so.Join("chat")
		so.On("chat message", func(msg string) {
			log.Println("emit:", so.Emit("chat message", msg))
			so.BroadcastTo("chat", "chat message", msg)
		})
		so.On("disconnection", func() {
			log.Println("on disconnect")
		})
	})
	server.On("error", func(so socketio.Socket, err error) {
		log.Println("error:", err)
	})
	http.Handle("/socket.io/", server)
	http.Handle("/", http.FileServer(http.Dir("./asset")))
	log.Println("Serving at localhost:5000...")
	log.Fatal(http.ListenAndServe(":5000", nil))
}

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

Sending ACK with data from SERVER to CLIENT

 //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));
 });

// 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
so.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

//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
}

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

License