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- // Copyright 2010 The Go Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style
- // license that can be found in the LICENSE file.
- package main
- import (
- "errors"
- "html/template"
- "io/ioutil"
- "log"
- "net/http"
- "regexp"
- )
- type Page struct {
- Title string
- Body []byte
- }
- func (p *Page) save() error {
- filename := p.Title + ".txt"
- return ioutil.WriteFile(filename, p.Body, 0600)
- }
- func loadPage(title string) (*Page, error) {
- filename := title + ".txt"
- body, err := ioutil.ReadFile(filename)
- if err != nil {
- return nil, err
- }
- return &Page{Title: title, Body: body}, nil
- }
- func viewHandler(w http.ResponseWriter, r *http.Request) {
- title, err := getTitle(w, r)
- if err != nil {
- return
- }
- p, err := loadPage(title)
- if err != nil {
- http.Redirect(w, r, "/edit/"+title, http.StatusFound)
- return
- }
- renderTemplate(w, "view", p)
- }
- func editHandler(w http.ResponseWriter, r *http.Request) {
- title, err := getTitle(w, r)
- if err != nil {
- return
- }
- p, err := loadPage(title)
- if err != nil {
- p = &Page{Title: title}
- }
- renderTemplate(w, "edit", p)
- }
- func saveHandler(w http.ResponseWriter, r *http.Request) {
- title, err := getTitle(w, r)
- if err != nil {
- return
- }
- body := r.FormValue("body")
- p := &Page{Title: title, Body: []byte(body)}
- err = p.save()
- if err != nil {
- http.Error(w, err.Error(), http.StatusInternalServerError)
- return
- }
- http.Redirect(w, r, "/view/"+title, http.StatusFound)
- }
- func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
- t, err := template.ParseFiles(tmpl + ".html")
- if err != nil {
- http.Error(w, err.Error(), http.StatusInternalServerError)
- return
- }
- err = t.Execute(w, p)
- if err != nil {
- http.Error(w, err.Error(), http.StatusInternalServerError)
- }
- }
- var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
- func getTitle(w http.ResponseWriter, r *http.Request) (string, error) {
- m := validPath.FindStringSubmatch(r.URL.Path)
- if m == nil {
- http.NotFound(w, r)
- return "", errors.New("Invalid Page Title")
- }
- return m[2], nil // The title is the second subexpression.
- }
- func main() {
- http.HandleFunc("/view/", viewHandler)
- http.HandleFunc("/edit/", editHandler)
- http.HandleFunc("/save/", saveHandler)
- log.Fatal(http.ListenAndServe(":8080", nil))
- }
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