1 // Copyright 2010 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package main 6 7 import ( 8 "html/template" 9 "io/ioutil" 10 "net/http" 11 "regexp" 12 ) 13 14 type Page struct { 15 Title string 16 Body []byte 17 } 18 19 func (p *Page) save() error { 20 filename := p.Title + ".txt" 21 return ioutil.WriteFile(filename, p.Body, 0600) 22 } 23 24 func loadPage(title string) (*Page, error) { 25 filename := title + ".txt" 26 body, err := ioutil.ReadFile(filename) 27 if err != nil { 28 return nil, err 29 } 30 return &Page{Title: title, Body: body}, nil 31 } 32 33 func viewHandler(w http.ResponseWriter, r *http.Request, title string) { 34 p, err := loadPage(title) 35 if err != nil { 36 http.Redirect(w, r, "/edit/"+title, http.StatusFound) 37 return 38 } 39 renderTemplate(w, "view", p) 40 } 41 42 func editHandler(w http.ResponseWriter, r *http.Request, title string) { 43 p, err := loadPage(title) 44 if err != nil { 45 p = &Page{Title: title} 46 } 47 renderTemplate(w, "edit", p) 48 } 49 50 func saveHandler(w http.ResponseWriter, r *http.Request, title string) { 51 body := r.FormValue("body") 52 p := &Page{Title: title, Body: []byte(body)} 53 err := p.save() 54 if err != nil { 55 http.Error(w, err.Error(), http.StatusInternalServerError) 56 return 57 } 58 http.Redirect(w, r, "/view/"+title, http.StatusFound) 59 } 60 61 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) { 62 t, err := template.ParseFiles(tmpl + ".html") 63 if err != nil { 64 http.Error(w, err.Error(), http.StatusInternalServerError) 65 return 66 } 67 err = t.Execute(w, p) 68 if err != nil { 69 http.Error(w, err.Error(), http.StatusInternalServerError) 70 } 71 } 72 73 var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$") 74 75 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc { 76 return func(w http.ResponseWriter, r *http.Request) { 77 m := validPath.FindStringSubmatch(r.URL.Path) 78 if m == nil { 79 http.NotFound(w, r) 80 return 81 } 82 fn(w, r, m[2]) 83 } 84 } 85 86 func main() { 87 http.HandleFunc("/view/", makeHandler(viewHandler)) 88 http.HandleFunc("/edit/", makeHandler(editHandler)) 89 http.HandleFunc("/save/", makeHandler(saveHandler)) 90 http.ListenAndServe(":8080", nil) 91 } 92
