1
2
3
4
5 package main
6
7 import (
8 "html/template"
9 "io/ioutil"
10 "log"
11 "net/http"
12 "regexp"
13 )
14
15 type Page struct {
16 Title string
17 Body []byte
18 }
19
20 func (p *Page) save() error {
21 filename := p.Title + ".txt"
22 return ioutil.WriteFile(filename, p.Body, 0600)
23 }
24
25 func loadPage(title string) (*Page, error) {
26 filename := title + ".txt"
27 body, err := ioutil.ReadFile(filename)
28 if err != nil {
29 return nil, err
30 }
31 return &Page{Title: title, Body: body}, nil
32 }
33
34 func viewHandler(w http.ResponseWriter, r *http.Request, title string) {
35 p, err := loadPage(title)
36 if err != nil {
37 http.Redirect(w, r, "/edit/"+title, http.StatusFound)
38 return
39 }
40 renderTemplate(w, "view", p)
41 }
42
43 func editHandler(w http.ResponseWriter, r *http.Request, title string) {
44 p, err := loadPage(title)
45 if err != nil {
46 p = &Page{Title: title}
47 }
48 renderTemplate(w, "edit", p)
49 }
50
51 func saveHandler(w http.ResponseWriter, r *http.Request, title string) {
52 body := r.FormValue("body")
53 p := &Page{Title: title, Body: []byte(body)}
54 err := p.save()
55 if err != nil {
56 http.Error(w, err.Error(), http.StatusInternalServerError)
57 return
58 }
59 http.Redirect(w, r, "/view/"+title, http.StatusFound)
60 }
61
62 var templates = template.Must(template.ParseFiles("edit.html", "view.html"))
63
64 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
65 err := templates.ExecuteTemplate(w, tmpl+".html", p)
66 if err != nil {
67 http.Error(w, err.Error(), http.StatusInternalServerError)
68 }
69 }
70
71 var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
72
73 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
74 return func(w http.ResponseWriter, r *http.Request) {
75 m := validPath.FindStringSubmatch(r.URL.Path)
76 if m == nil {
77 http.NotFound(w, r)
78 return
79 }
80 fn(w, r, m[2])
81 }
82 }
83
84 func main() {
85 http.HandleFunc("/view/", makeHandler(viewHandler))
86 http.HandleFunc("/edit/", makeHandler(editHandler))
87 http.HandleFunc("/save/", makeHandler(saveHandler))
88
89 log.Fatal(http.ListenAndServe(":8080", nil))
90 }
91
View as plain text