stroum/index.html

## index.html
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script>
		function lp() {
			var http = new XMLHttpRequest();
			http.open('GET', '/lp', true);
			http.onreadystatechange = function(event) {
				if (this.readyState == 4) {
					if (this.status == 200) {
						if (http.responseText.length) {
							document.querySelector('.messages').innerHTML += '<div class="message">' + http.responseText + '</div>';
							down();
						}
						lp();
					}
				}
			}
			http.send(null);
		}
		lp();

		window.onload = function() {
			down();

			document.getElementById("send").onclick = function() {
				var http = new XMLHttpRequest();
				http.onreadystatechange = function() {
					if (this.readyState == 4) {
						if (this.status == 200) {
							console.log(http.responseText);
						}
					}
				}
				msg = document.getElementById('msg').value;
				http.open('GET', '/msg?msg=' + msg);
				http.send(null);
				document.getElementById('msg').value = '';
				return false;
			}
		}

        function down() {
            document.querySelector(".messages").scrollTop += 99999;
        }
	</script>
	<style>
		.messages {
			overflow-y: auto;
			height: 500px;
			border: 1px solid #000;
		}
		.message {
			background: #f5f5f5;
			border: 1px solid #ccc;
			padding:10px;
		}
	</style>
</head>
<body>
	<div class="hello">Hello, World!</div>
	<form action="/lp">
		<textarea id="msg" name="msg" rows="3" style="width: 50%;"></textarea><br>
		<input id="send" type="submit" value="OK">
	</form>
	<br>
	<div class="chat">
		<div class="messages">

		</div>
	</div>
</body>
</html>

## longpoll.go
package main

import (
	"fmt"
	"html"
	"io"
	"log"
	"net/http"
	"time"
)

var lpchan = make(chan chan string)

func MakeLPHandler(w http.ResponseWriter, r *http.Request) {
	myRequestChan := make(chan string)

	select {
	case lpchan <- myRequestChan:
		io.WriteString(w, html.EscapeString(<-myRequestChan))
	case <-time.After(30 * time.Second):
		return
	}
}

func NewMsgHandler(w http.ResponseWriter, r *http.Request) {
	msg := r.FormValue("msg")
	if len(msg) > 0 {
		for {
			select {
			case clientchan := <-lpchan:
				clientchan <- msg
			default:
				return
			}
		}
	}
}

func handler(w http.ResponseWriter, req *http.Request) {
	/*w.Header().Set("Content-type", "text/html")
	t, _ := template.ParseFiles("index.html")
	t.Execute(w, nil)*/
	http.ServeFile(w, req, "index.html")
}

func main() {
	fmt.Println("Starting server on http://127.0.0.1:3000/")
	s := &http.Server{
		Addr:           ":3000",
		ReadTimeout:    1000 * time.Second,
		WriteTimeout:   1000 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	http.HandleFunc("/", handler)
	http.HandleFunc("/lp", MakeLPHandler)
	http.HandleFunc("/msg", NewMsgHandler)
	log.Fatal(s.ListenAndServe())
}
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script>
	function lp() {
	var http = new XMLHttpRequest();
	http.open('GET', '/lp', true);
	http.onreadystatechange = function(event) {
	if (this.readyState == 4) {
	if (this.status == 200) {
	if (http.responseText.length) {
	document.querySelector('.messages').innerHTML += '<div class="message">' + http.responseText + '</div>';
	down();
	}
	lp();
	}
	}
	}
	http.send(null);
	}
	lp();

	window.onload = function() {
	down();

	document.getElementById("send").onclick = function() {
	var http = new XMLHttpRequest();
	http.onreadystatechange = function() {
	if (this.readyState == 4) {
	if (this.status == 200) {
	console.log(http.responseText);
	}
	}
	}
	msg = document.getElementById('msg').value;
	http.open('GET', '/msg?msg=' + msg);
	http.send(null);
	document.getElementById('msg').value = '';
	return false;
	}
	}

	function down() {
	document.querySelector(".messages").scrollTop += 99999;
	}
	</script>
	<style>
	.messages {
	overflow-y: auto;
	height: 500px;
	border: 1px solid #000;
	}
	.message {
	background: #f5f5f5;
	border: 1px solid #ccc;
	padding:10px;
	}
	</style>
	</head>
	<body>
	<div class="hello">Hello, World!</div>
	<form action="/lp">
	<textarea id="msg" name="msg" rows="3" style="width: 50%;"></textarea><br>
	<input id="send" type="submit" value="OK">
	</form>
	<br>
	<div class="chat">
	<div class="messages">

	</div>
	</div>
	</body>
	</html>
	package main

	import (
	"fmt"
	"html"
	"io"
	"log"
	"net/http"
	"time"
	)

	var lpchan = make(chan chan string)

	func MakeLPHandler(w http.ResponseWriter, r *http.Request) {
	myRequestChan := make(chan string)

	select {
	case lpchan <- myRequestChan:
	io.WriteString(w, html.EscapeString(<-myRequestChan))
	case <-time.After(30 * time.Second):
	return
	}
	}

	func NewMsgHandler(w http.ResponseWriter, r *http.Request) {
	msg := r.FormValue("msg")
	if len(msg) > 0 {
	for {
	select {
	case clientchan := <-lpchan:
	clientchan <- msg
	default:
	return
	}
	}
	}
	}

	func handler(w http.ResponseWriter, req *http.Request) {
	/*w.Header().Set("Content-type", "text/html")
	t, _ := template.ParseFiles("index.html")
	t.Execute(w, nil)*/
	http.ServeFile(w, req, "index.html")
	}

	func main() {
	fmt.Println("Starting server on http://127.0.0.1:3000/")
	s := &http.Server{
	Addr: ":3000",
	ReadTimeout: 1000 * time.Second,
	WriteTimeout: 1000 * time.Second,
	MaxHeaderBytes: 1 << 20,
	}
	http.HandleFunc("/", handler)
	http.HandleFunc("/lp", MakeLPHandler)
	http.HandleFunc("/msg", NewMsgHandler)
	log.Fatal(s.ListenAndServe())
	}