Untitled

// Copyright 2015 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build ignore

package main

import (
    "flag"
    "html/template"
    "log"
    "net/http"

    "github.com/gorilla/websocket"
)

var addr = flag.String("addr", "127.0.0.1:8080", "http service address")

var upgrader = websocket.Upgrader{} // use default options

func echo(w http.ResponseWriter, r *http.Request) {
    c, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        log.Print("upgrade:", err)
        return
    }
    defer c.Close()
    for {
        mt, message, err := c.ReadMessage()
        if err != nil {
            log.Println("read:", err)
            break
        }
        log.Printf("recv: %s", message)
        err = c.WriteMessage(mt, message)
        if err != nil {
            log.Println("write:", err)
            break
        }
    }
}

func home(w http.ResponseWriter, r *http.Request) {
    homeTemplate.Execute(w, "ws://"+r.Host+"/echo")
}

func main() {

    flag.Parse()
    log.SetFlags(0)
    http.HandleFunc("/echo", echo)
    http.HandleFunc("/", home)
    log.Fatal(http.ListenAndServe(*addr, nil))
}

var homeTemplate = template.Must(template.New("").Parse(`
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
window.addEventListener("load", function(evt) {

    var output = document.getElementById("output");
    var input = document.getElementById("input");
    var ws;

    var print = function(message) {
        var d = document.createElement("div");
        d.innerHTML = message;
        output.appendChild(d);
    };

    document.getElementById("open").onclick = function(evt) {
        if (ws) {
            return false;
        }
        ws = new WebSocket("{{.}}");
        ws.onopen = function(evt) {
            print("OPEN");
        }
        ws.onclose = function(evt) {
            print("CLOSE");
            ws = null;
        }
        ws.onmessage = function(evt) {
            print("RESPONSE: " + evt.data);
        }
        ws.onerror = function(evt) {
            print("ERROR: " + evt.data);
        }
        return false;
    };

    document.getElementById("send").onclick = function(evt) {
        if (!ws) {
            return false;
        }
        print("SEND: " + input.value);
        ws.send(input.value);
        return false;
    };

    document.getElementById("close").onclick = function(evt) {
        if (!ws) {
            return false;
        }
        ws.close();
        return false;
    };

});
</script>
</head>
<body>
<table>
<tr><td valign="top" width="50%">
<p>Click "Open" to create a connection to the server,
"Send" to send a message to the server and "Close" to close the connection.
You can change the message and send multiple times.
<p>
<form>
<button id="open">Open</button>
<button id="close">Close</button>
<p><input id="input" type="text" value="Hello world!">
<button id="send">Send</button>
</form>
</td><td valign="top" width="50%">
<div id="output"></div>
</td></tr></table>
</body>
</html>
`))