capexample/main.go (view raw)
1// Copyright 2011 Dmitry Chestnykh. All rights reserved.
2// Use of this source code is governed by a MIT-style
3// license that can be found in the LICENSE file.
4
5// example of HTTP server that uses the captcha package.
6package main
7
8import (
9 "fmt"
10 "github.com/dchest/captcha"
11 "io"
12 "log"
13 "net/http"
14 "text/template"
15)
16
17var formTemplate = template.Must(template.New("example").Parse(formTemplateSrc))
18
19func showFormHandler(w http.ResponseWriter, r *http.Request) {
20 if r.URL.Path != "/" {
21 http.NotFound(w, r)
22 return
23 }
24 d := struct {
25 CaptchaId string
26 }{
27 captcha.New(),
28 }
29 if err := formTemplate.Execute(w, &d); err != nil {
30 http.Error(w, err.Error(), http.StatusInternalServerError)
31 }
32}
33
34func processFormHandler(w http.ResponseWriter, r *http.Request) {
35 w.Header().Set("Content-Type", "text/html; charset=utf-8")
36 if !captcha.VerifyString(r.FormValue("captchaId"), r.FormValue("captchaSolution")) {
37 io.WriteString(w, "Wrong captcha solution! No robots allowed!\n")
38 } else {
39 io.WriteString(w, "Great job, human! You solved the captcha.\n")
40 }
41 io.WriteString(w, "<br><a href='/'>Try another one</a>")
42}
43
44func main() {
45 http.HandleFunc("/", showFormHandler)
46 http.HandleFunc("/process", processFormHandler)
47 http.Handle("/captcha/", captcha.Server(captcha.StdWidth, captcha.StdHeight))
48 fmt.Println("Server is at localhost:8666")
49 if err := http.ListenAndServe("localhost:8666", nil); err != nil {
50 log.Fatal(err)
51 }
52}
53
54const formTemplateSrc = `<!doctype html>
55<head><title>Captcha Example</title></head>
56<body>
57<script>
58function setSrcQuery(e, q) {
59 var src = e.src;
60 var p = src.indexOf('?');
61 if (p >= 0) {
62 src = src.substr(0, p);
63 }
64 e.src = src + "?" + q
65}
66
67function playAudio() {
68 var le = document.getElementById("lang");
69 var lang = le.options[le.selectedIndex].value;
70 var e = document.getElementById('audio')
71 setSrcQuery(e, "lang=" + lang)
72 e.style.display = 'block';
73 e.autoplay = 'true';
74 return false;
75}
76
77function changeLang() {
78 var e = document.getElementById('audio')
79 if (e.style.display == 'block') {
80 playAudio();
81 }
82}
83
84function reload() {
85 setSrcQuery(document.getElementById('image'), "reload=" + (new Date()).getTime());
86 setSrcQuery(document.getElementById('audio'), (new Date()).getTime());
87 return false;
88}
89</script>
90<select id="lang" onchange="changeLang()">
91 <option value="en">English</option>
92 <option value="ja">Japanese</option>
93 <option value="ru">Russian</option>
94 <option value="zh">Chinese</option>
95</select>
96<form action="/process" method=post>
97<p>Type the numbers you see in the picture below:</p>
98<p><img id=image src="/captcha/{{.CaptchaId}}.png" alt="Captcha image"></p>
99<a href="#" onclick="reload()">Reload</a> | <a href="#" onclick="playAudio()">Play Audio</a>
100<audio id=audio controls style="display:none" src="/captcha/{{.CaptchaId}}.wav" preload=none>
101 You browser doesn't support audio.
102 <a href="/captcha/download/{{.CaptchaId}}.wav">Download file</a> to play it in the external player.
103</audio>
104<input type=hidden name=captchaId value="{{.CaptchaId}}"><br>
105<input name=captchaSolution>
106<input type=submit value=Submit>
107</form>
108`