Support keepalive PING messages on the socket

client.go

@@ -15,7 +15,9 @@ type Client struct {
 	id     string
 	ws     *websocket.Conn
 	server *Server
-	ch     chan *Message
+	ch     chan *ChatMessage
+	pingch chan *PingMessage
+
 	doneCh chan bool
 }
 
@@ -30,17 +32,18 @@ func NewClient(ws *websocket.Conn, server *Server) *Client {
 		panic("server cannot be nil")
 	}
 
-	ch := make(chan *Message, channelBufSize)
+	ch := make(chan *ChatMessage, channelBufSize)
 	doneCh := make(chan bool)
+	pingch := make(chan *PingMessage)
 	clientID := getClientIDFromRequest(ws.Request())
-	return &Client{clientID, ws, server, ch, doneCh}
+	return &Client{clientID, ws, server, ch, pingch, doneCh}
 }
 
 func (c *Client) Conn() *websocket.Conn {
 	return c.ws
 }
 
-func (c *Client) Write(msg *Message) {
+func (c *Client) Write(msg *ChatMessage) {
 	select {
 	case c.ch <- msg:
 	default:
@@ -64,9 +67,12 @@ func (c *Client) Listen() {
 func (c *Client) listenWrite() {
 	for {
 		select {
-
+		// Send a PING keepalive
+		case msg := <-c.pingch:
+			websocket.JSON.Send(c.ws, msg)
 		// send message to the client
 		case msg := <-c.ch:
+			msg.MessageType = "CHAT"
 			log.Println("Send:", msg)
 			websocket.JSON.Send(c.ws, msg)
 
@@ -92,7 +98,7 @@ func (c *Client) listenRead() {
 
 		// read data from websocket connection
 		default:
-			var msg Message
+			var msg ChatMessage
 			err := websocket.JSON.Receive(c.ws, &msg)
 			if err == io.EOF {
 				c.doneCh <- true

message.go

@@ -1,12 +1,25 @@
 package main
 
-type Message struct {
+type ChatMessage struct {
 	Author      string `json:"author"`
 	Body        string `json:"body"`
 	Image       string `json:"image"`
-	Id     string `json:"id"`
+	ID          string `json:"id"`
+	MessageType string `json:"type"`
 }
 
-func (self *Message) String() string {
-	return self.Author + " says " + self.Body
+func (s *ChatMessage) AsJson() string {
+	return s.Author + " says " + s.Body
+}
+
+func (s *ChatMessage) String() string {
+	return s.Author + " says " + s.Body
+}
+
+type PingMessage struct {
+	MessageType string `json:"type"`
+}
+
+func (self *PingMessage) AsJson() string {
+	return "{type: \"PING\"}"
 }

server.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"net/http"
+	"time"
 
 	"golang.org/x/net/websocket"
 )
@@ -10,43 +12,58 @@ import (
 // Chat server.
 type Server struct {
 	pattern   string
-	messages  []*Message
+	messages  []*ChatMessage
 	clients   map[string]*Client
 	addCh     chan *Client
 	delCh     chan *Client
-	sendAllCh chan *Message
+	sendAllCh chan *ChatMessage
+	pingCh    chan *PingMessage
 	doneCh    chan bool
 	errCh     chan error
 }
 
 // Create new chat server.
 func NewServer(pattern string) *Server {
-	messages := []*Message{}
+	messages := []*ChatMessage{}
 	clients := make(map[string]*Client)
 	addCh := make(chan *Client)
 	delCh := make(chan *Client)
-	sendAllCh := make(chan *Message)
+	sendAllCh := make(chan *ChatMessage)
+	pingCh := make(chan *PingMessage)
 	doneCh := make(chan bool)
 	errCh := make(chan error)
 
 	// Demo messages only.  Remove me eventually!!!
-	messages = append(messages, &Message{"Tom Nook", "I'll be there with Bells on! Ho ho!", "https://gamepedia.cursecdn.com/animalcrossingpocketcamp_gamepedia_en/thumb/4/4f/Timmy_Icon.png/120px-Timmy_Icon.png?version=87b38d7d6130411d113486c2db151385", "demo-message-1"})
-	messages = append(messages, &Message{"Redd", "Fool me once, shame on you. Fool me twice, stop foolin' me.", "https://vignette.wikia.nocookie.net/animalcrossing/images/3/3d/Redd2.gif/revision/latest?cb=20100710004252", "demo-message-2"})
-	messages = append(messages, &Message{"Kevin", "You just caught me before I was about to go work out weeweewee!", "https://vignette.wikia.nocookie.net/animalcrossing/images/2/20/NH-Kevin_poster.png/revision/latest/scale-to-width-down/100?cb=20200410185817", "demo-message-3"})
-	messages = append(messages, &Message{"Isabelle", " Isabelle is the mayor's highly capable secretary. She can be forgetful sometimes, but you can always count on her for information about the town. She wears her hair up in a bun that makes her look like a shih tzu. Mostly because she is one! She also has a twin brother named Digby.", "https://dodo.ac/np/images/thumb/7/7b/IsabelleTrophyWiiU.png/200px-IsabelleTrophyWiiU.png", "demo-message-4"})
-	messages = append(messages, &Message{"Judy", "myohmy, I'm dancing my dreams away.", "https://vignette.wikia.nocookie.net/animalcrossing/images/5/50/NH-Judy_poster.png/revision/latest/scale-to-width-down/100?cb=20200522063219", "demo-message-5"})
-	messages = append(messages, &Message{"Blathers", "Blathers is an owl with brown feathers. His face is white and he has a yellow beak. His arms are wing shaped and he has yellow talons. His eyes are very big with small black irises. He also has big pink cheek circles on his cheeks. His belly appears to be checkered in diamonds with light brown and white squares, similar to an argyle vest, which is traditionally associated with academia. His green bowtie further alludes to his academic nature.", "https://vignette.wikia.nocookie.net/animalcrossing/images/b/b3/NH-character-Blathers.png/revision/latest?cb=20200229053519", "demo-message-6"})
-
-	return &Server{
+	messages = append(messages, &ChatMessage{"Tom Nook", "I'll be there with Bells on! Ho ho!", "https://gamepedia.cursecdn.com/animalcrossingpocketcamp_gamepedia_en/thumb/4/4f/Timmy_Icon.png/120px-Timmy_Icon.png?version=87b38d7d6130411d113486c2db151385", "demo-message-1", "ChatMessage"})
+	messages = append(messages, &ChatMessage{"Redd", "Fool me once, shame on you. Fool me twice, stop foolin' me.", "https://vignette.wikia.nocookie.net/animalcrossing/images/3/3d/Redd2.gif/revision/latest?cb=20100710004252", "demo-message-2", "ChatMessage"})
+	messages = append(messages, &ChatMessage{"Kevin", "You just caught me before I was about to go work out weeweewee!", "https://vignette.wikia.nocookie.net/animalcrossing/images/2/20/NH-Kevin_poster.png/revision/latest/scale-to-width-down/100?cb=20200410185817", "demo-message-3", "ChatMessage"})
+	messages = append(messages, &ChatMessage{"Isabelle", " Isabelle is the mayor's highly capable secretary. She can be forgetful sometimes, but you can always count on her for information about the town. She wears her hair up in a bun that makes her look like a shih tzu. Mostly because she is one! She also has a twin brother named Digby.", "https://dodo.ac/np/images/thumb/7/7b/IsabelleTrophyWiiU.png/200px-IsabelleTrophyWiiU.png", "demo-message-4", "ChatMessage"})
+	messages = append(messages, &ChatMessage{"Judy", "myohmy, I'm dancing my dreams away.", "https://vignette.wikia.nocookie.net/animalcrossing/images/5/50/NH-Judy_poster.png/revision/latest/scale-to-width-down/100?cb=20200522063219", "demo-message-5", "ChatMessage"})
+	messages = append(messages, &ChatMessage{"Blathers", "Blathers is an owl with brown feathers. His face is white and he has a yellow beak. His arms are wing shaped and he has yellow talons. His eyes are very big with small black irises. He also has big pink cheek circles on his cheeks. His belly appears to be checkered in diamonds with light brown and white squares, similar to an argyle vest, which is traditionally associated with academia. His green bowtie further alludes to his academic nature.", "https://vignette.wikia.nocookie.net/animalcrossing/images/b/b3/NH-character-Blathers.png/revision/latest?cb=20200229053519", "demo-message-6", "ChatMessage"})
+
+	server := &Server{
 		pattern,
 		messages,
 		clients,
 		addCh,
 		delCh,
 		sendAllCh,
+		pingCh,
 		doneCh,
 		errCh,
 	}
+
+	ticker := time.NewTicker(30 * time.Second)
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				server.ping()
+			}
+		}
+	}()
+
+	return server
 }
 
 func (s *Server) ClientCount() int {
@@ -61,7 +78,7 @@ func (s *Server) Del(c *Client) {
 	s.delCh <- c
 }
 
-func (s *Server) SendAll(msg *Message) {
+func (s *Server) SendAll(msg *ChatMessage) {
 	s.sendAllCh <- msg
 }
 
@@ -79,12 +96,21 @@ func (s *Server) sendPastMessages(c *Client) {
 	}
 }
 
-func (s *Server) sendAll(msg *Message) {
+func (s *Server) sendAll(msg *ChatMessage) {
 	for _, c := range s.clients {
 		c.Write(msg)
 	}
 }
 
+func (s *Server) ping() {
+	// fmt.Println("Start pinging....", len(s.clients))
+
+	ping := &PingMessage{"PING"}
+	for _, c := range s.clients {
+		c.pingch <- ping
+	}
+}
+
 // Listen and serve.
 // It serves client connection and broadcast request.
 func (s *Server) Listen() {
@@ -123,6 +149,9 @@ func (s *Server) Listen() {
 			s.messages = append(s.messages, msg)
 			s.sendAll(msg)
 
+		case ping := <-s.pingCh:
+			fmt.Println("PING?", ping)
+
 		case err := <-s.errCh:
 			log.Println("Error:", err.Error())
 
@@ -130,4 +159,5 @@ func (s *Server) Listen() {
 			return
 		}
 	}
+
 }

webroot/js/app.js

@@ -33,7 +33,7 @@ function setupApp() {
 }
 
 async function getStatus() {
-  let url = "https://util.real-ity.com:8042/status";
+  let url = "https://goth.land/status";
 
   try {
     const response = await fetch(url);
@@ -57,11 +57,18 @@ var websocketReconnectTimer;
 function setupWebsocket() {
   clearTimeout(websocketReconnectTimer)
 
-  const protocol = location.protocol == "https:" ? "wss" : "ws"
-  var ws = new WebSocket("wss://util.real-ity.com:8042/entry")
+  // Uncomment to point to somewhere other than goth.land
+  // const protocol = location.protocol == "https:" ? "wss" : "ws"
+  // var ws = new WebSocket(protocol + "://" + location.host + "/entry")
+
+  var ws = new WebSocket("wss://goth.land/entry")
 
   ws.onmessage = (e) => {
     const model = JSON.parse(e.data)
+
+    // Ignore non-chat messages (such as keepalive PINGs)
+    if (model.type !== SocketMessageTypes.CHAT) { return; }
+
     const message = new Message(model)
 
     const existing = this.messagesContainer.messages.filter(function (item) {

webroot/js/config.js

@@ -11,8 +11,6 @@ class Config {
       const response = await fetch(configFileLocation);
       const configData = await response.json();
       Object.assign(this, configData);
-      console.log(this);
-
     } catch(error) {
       console.log(error);
       // No config file present.  That's ok.  It's not required.

webroot/js/message.js

@@ -1,9 +1,15 @@
+const SocketMessageTypes = {
+	CHAT: "CHAT",
+	PING: "PING"
+}
+
 class Message {
 	constructor(model) {
 		this.author = model.author;
 		this.body = model.body;
 		this.image = model.image || "https://robohash.org/" + model.author;
 		this.id = model.id;
+		this.type = model.type;
 	}
 
 	addNewlines(str) {