gosocketio

README

golang socket.io

golang implementation of socket.io library, client and server

You can check working chat server, based on caller library, at http://funstream.tv

Examples directory contains simple client and server.

Installation

go get github.com/graarh/golang-socketio

Simple server usage

	//create
	server := gosocketio.NewServer(transport.GetDefaultWebsocketTransport())

	//handle connected
	server.On(gosocketio.OnConnection, func(c *gosocketio.Channel) {
		log.Println("New client connected")
		//join them to room
		c.Join("chat")
	})

	type Message struct {
		Name string `json:"name"`
		Message string `json:"message"`
	}

	//handle custom event
	server.On("send", func(c *gosocketio.Channel, msg Message) string {
		//send event to all in room
		c.BroadcastTo("chat", "message", msg)
		return "OK"
	})

	//setup http server
	serveMux := http.NewServeMux()
	serveMux.Handle("/socket.io/", server)
	log.Panic(http.ListenAndServe(":80", serveMux))

Javascript client for caller server

var socket = io('ws://yourdomain.com', {transports: ['websocket']});

    // listen for messages
    socket.on('message', function(message) {

        console.log('new message');
        console.log(message);
    });

    socket.on('connect', function () {

        console.log('socket connected');

        //send something
        socket.emit('send', {name: "my name", message: "hello"}, function(result) {

            console.log('sended successfully');
            console.log(result);
        });
    });

Server, detailed usage

    //create server instance, you can setup transport parameters or get the default one
    //look at websocket.go for parameters description
	server := gosocketio.NewServer(transport.GetDefaultWebsocketTransport())

	// --- caller is default handlers

	//on connection handler, occurs once for each connected client
	server.On(gosocketio.OnConnection, func(c *gosocketio.Channel, args interface{}) {
	    //client id is unique
		log.Println("New client connected, client id is ", c.Id())

		//you can join clients to rooms
		c.Join("room name")

		//of course, you can list the clients in the room, or account them
		channels := c.List(data.Channel)
		//or check the amount of clients in room
		amount := c.Amount(data.Channel)
		log.Println(amount, "clients in room")
	})
	//on disconnection handler, if client hangs connection unexpectedly, it will still occurs
	//you can omit function args if you do not need them
	//you can return string value for ack, or return nothing for emit
	server.On(gosocketio.OnDisconnection, func(c *gosocketio.Channel) {
		//caller is not necessary, client will be removed from rooms
		//automatically on disconnect
		//but you can remove client from room whenever you need to
		c.Leave("room name")

		log.Println("Disconnected")
	})
	//error catching handler
	server.On(gosocketio.OnError, func(c *gosocketio.Channel) {
		log.Println("Error occurs")
	})

	// --- caller is custom handler

	//custom event handler
	server.On("handle something", func(c *gosocketio.Channel, channel Channel) string {
		log.Println("Something successfully handled")

		//you can return result of handler, in caller case
		//handler will be converted from "emit" to "ack"
		return "result"
	})

    //you can get client connection by it's id
    channel, _ := server.GetChannel("client id here")
    //and send the event to the client
    type MyEventData struct {
        Data: string
    }
    channel.Emit("my event", MyEventData{"my data"})

    //or you can send ack to client and get result back
    result, err := channel.Ack("my custom ack", MyEventData{"ack data"}, time.Second * 5)

    //you can broadcast to all clients
    server.BroadcastToAll("my event", MyEventData{"broadcast"})

    //or for clients joined to room
    server.BroadcastTo("my room", "my event", MyEventData{"room broadcast"})

    //setup http server like caller for handling connections
	serveMux := http.NewServeMux()
	serveMux.Handle("/socket.io/", server)
	log.Panic(http.ListenAndServe(":80", serveMux))

Client

    //connect to server, you can use your own transport settings
	c, err := gosocketio.Dial(
		gosocketio.GetUrl("localhost", 80, false),
		transport.GetDefaultWebsocketTransport(),
	)

	//do something, handlers and functions are same as server ones

	//close connection
	c.Close()

Roadmap

1. Tests
2. Travis CI
3. http longpoll transport
4. pure http (short-timed queries) transport
5. binary format

Licence

Double licensed under GPL3 and MIT so you can use whichever you please.

Documentation

Index

• Constants
• Variables
• func AmountOfOverflooded() int64
• func GetUrl(host string, port int, secure bool) string
• type Channel
  • func (c *Channel) Ack(method string, args interface{}, timeout time.Duration) (string, error)
  • func (c *Channel) Amount(room string) int
  • func (c *Channel) BroadcastTo(room, method string, args interface{})
  • func (c *Channel) Close()
  • func (c *Channel) Emit(method string, args interface{}) error
  • func (c *Channel) Id() string
  • func (c *Channel) Ip() string
  • func (c *Channel) IsAlive() bool
  • func (c *Channel) Join(room string) error
  • func (c *Channel) Leave(room string) error
  • func (c *Channel) List(room string) []*Channel
  • func (c *Channel) RequestHeader() http.Header
• type Client
  • func Dial(url string, tr transport.Transport) (*Client, error)
  • func (c *Client) Close()
  • func (m *Client) On(method string, f interface{}) error
• type Header
• type Server
  • func NewServer(tr transport.Transport) *Server
  • func (s *Server) Amount(room string) int
  • func (s *Server) AmountOfRooms() int64
  • func (s *Server) AmountOfSids() int64
  • func (s *Server) BroadcastTo(room, method string, args interface{})
  • func (s *Server) BroadcastToAll(method string, args interface{})
  • func (s *Server) GetChannel(sid string) (*Channel, error)
  • func (s *Server) List(room string) []*Channel
  • func (m *Server) On(method string, f interface{}) error
  • func (s *Server) SendOpenSequence(c *Channel)
  • func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request)
  • func (s *Server) SetupEventLoop(conn transport.Connection, remoteAddr string, requestHeader http.Header)

Constants

const (
	OnConnection    = "connection"
	OnDisconnection = "disconnection"
	OnError         = "error"
)

const (
	HeaderForward = "X-Forwarded-For"
)

Variables

var (
	ErrorCallerNotFunc     = errors.New("f is not function")
	ErrorCallerNot2Args    = errors.New("f should have 1 or 2 args")
	ErrorCallerMaxOneValue = errors.New("f should return not more than one value")
)

var (
	ErrorSendTimeout     = errors.New("Timeout")
	ErrorSocketOverflood = errors.New("Socket overflood")
)

var (
	ErrorServerNotSet       = errors.New("Server not set")
	ErrorConnectionNotFound = errors.New("Connection not found")
)

var (
	ErrorWaiterNotFound = errors.New("Waiter not found")
)

var (
	ErrorWrongHeader = errors.New("Wrong header")
)

Functions

func AmountOfOverflooded

func AmountOfOverflooded() int64

func GetUrl

func GetUrl(host string, port int, secure bool) string

* Get ws/wss url by host and port

Types

type Channel

type Channel struct {
	// contains filtered or unexported fields
}

* socket.io connection handler

use IsAlive to check that handler is still working use Dial to connect to websocket use In and Out channels for message exchange Close message means channel is closed ping is automatic

func (*Channel) Ack

func (c *Channel) Ack(method string, args interface{}, timeout time.Duration) (string, error)

* Create ack packet based on given data and send it and receive response

func (*Channel) Amount

func (c *Channel) Amount(room string) int

* Get amount of channels, joined to given room, using channel

func (*Channel) BroadcastTo

func (c *Channel) BroadcastTo(room, method string, args interface{})

func (*Channel) Close

func (c *Channel) Close()

* Close current channel

func (*Channel) Emit

func (c *Channel) Emit(method string, args interface{}) error

* Create packet based on given data and send it

func (*Channel) Id

func (c *Channel) Id() string

* Get id of current socket connection

func (*Channel) Ip

func (c *Channel) Ip() string

* Get ip of socket client

func (*Channel) IsAlive

func (c *Channel) IsAlive() bool

* Checks that Channel is still alive

func (*Channel) Join

func (c *Channel) Join(room string) error

* Join this channel to given room

func (*Channel) Leave

func (c *Channel) Leave(room string) error

* Remove this channel from given room

func (*Channel) List

func (c *Channel) List(room string) []*Channel

* Get list of channels, joined to given room, using channel

func (*Channel) RequestHeader

func (c *Channel) RequestHeader() http.Header

* Get request header of this connection

type Client

type Client struct {
	Channel
	// contains filtered or unexported fields
}

* Socket.io client representation

func Dial

func Dial(url string, tr transport.Transport) (*Client, error)

* connect to host and initialise socket.io protocol

The correct ws protocol url example: ws://myserver.com/socket.io/?EIO=3&transport=websocket

You can use GetUrlByHost for generating correct url

func (*Client) Close

func (c *Client) Close()

* Close client connection

func (*Client) On

func (m *Client) On(method string, f interface{}) error

* Add message processing function, and bind it to given method

type Header

type Header struct {
	Sid          string   `json:"sid"`
	Upgrades     []string `json:"upgrades"`
	PingInterval int      `json:"pingInterval"`
	PingTimeout  int      `json:"pingTimeout"`
}

* engine.io header to send or receive

type Server

type Server struct {
	http.Handler
	// contains filtered or unexported fields
}

* socket.io server instance

func NewServer

func NewServer(tr transport.Transport) *Server

* Create new socket.io server

func (*Server) Amount

func (s *Server) Amount(room string) int

* Get amount of channels, joined to given room, using server

func (*Server) AmountOfRooms

func (s *Server) AmountOfRooms() int64

* Get amount of rooms with at least one channel(or sid) joined

func (*Server) AmountOfSids

func (s *Server) AmountOfSids() int64

* Get amount of current connected sids

func (*Server) BroadcastTo

func (s *Server) BroadcastTo(room, method string, args interface{})

* Broadcast message to all room channels

func (*Server) BroadcastToAll

func (s *Server) BroadcastToAll(method string, args interface{})

* Broadcast to all clients

func (*Server) GetChannel

func (s *Server) GetChannel(sid string) (*Channel, error)

* Get channel by it's sid

func (*Server) List

func (s *Server) List(room string) []*Channel

* Get list of channels, joined to given room, using server

func (*Server) On

func (m *Server) On(method string, f interface{}) error

* Add message processing function, and bind it to given method

func (*Server) SendOpenSequence

func (s *Server) SendOpenSequence(c *Channel)

func (*Server) ServeHTTP

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request)

* implements ServeHTTP function from http.Handler

func (*Server) SetupEventLoop

func (s *Server) SetupEventLoop(conn transport.Connection, remoteAddr string,
	requestHeader http.Header)

* Setup event loop for given connection