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 "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 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) { 63 t, err := template.ParseFiles(tmpl + ".html") 64 if err != nil { 65 http.Error(w, err.Error(), http.StatusInternalServerError) 66 return 67 } 68 err = t.Execute(w, p) 69 if err != nil { 70 http.Error(w, err.Error(), http.StatusInternalServerError) 71 } 72 } 73 74 var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$") 75 76 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc { 77 return func(w http.ResponseWriter, r *http.Request) { 78 m := validPath.FindStringSubmatch(r.URL.Path) 79 if m == nil { 80 http.NotFound(w, r) 81 return 82 } 83 fn(w, r, m[2]) 84 } 85 } 86 87 func main() { 88 http.HandleFunc("/view/", makeHandler(viewHandler)) 89 http.HandleFunc("/edit/", makeHandler(editHandler)) 90 http.HandleFunc("/save/", makeHandler(saveHandler)) 91 log.Fatal(http.ListenAndServe(":8080", nil)) 92 } 93
