| package main |
| |
| import ( |
| "http" |
| "io/ioutil" |
| "os" |
| "regexp" |
| "template" |
| ) |
| |
| type page struct { |
| title string |
| body []byte |
| } |
| |
| func (p *page) save() os.Error { |
| filename := p.title + ".txt" |
| return ioutil.WriteFile(filename, p.body, 0600) |
| } |
| |
| func loadPage(title string) (*page, os.Error) { |
| filename := title + ".txt" |
| body, err := ioutil.ReadFile(filename) |
| if err != nil { |
| return nil, err |
| } |
| return &page{title: title, body: body}, nil |
| } |
| |
| func viewHandler(c *http.Conn, r *http.Request) { |
| title, err := getTitle(c, r) |
| if err != nil { |
| return |
| } |
| p, err := loadPage(title) |
| if err != nil { |
| http.Redirect(c, "/edit/"+title, http.StatusFound) |
| return |
| } |
| renderTemplate(c, "view", p) |
| } |
| |
| func editHandler(c *http.Conn, r *http.Request) { |
| title, err := getTitle(c, r) |
| if err != nil { |
| return |
| } |
| p, err := loadPage(title) |
| if err != nil { |
| p = &page{title: title} |
| } |
| renderTemplate(c, "edit", p) |
| } |
| |
| func saveHandler(c *http.Conn, r *http.Request) { |
| title, err := getTitle(c, r) |
| if err != nil { |
| return |
| } |
| body := r.FormValue("body") |
| p := &page{title: title, body: []byte(body)} |
| err = p.save() |
| if err != nil { |
| http.Error(c, err.String(), http.StatusInternalServerError) |
| return |
| } |
| http.Redirect(c, "/view/"+title, http.StatusFound) |
| } |
| |
| func renderTemplate(c *http.Conn, tmpl string, p *page) { |
| t, err := template.ParseFile(tmpl+".html", nil) |
| if err != nil { |
| http.Error(c, err.String(), http.StatusInternalServerError) |
| return |
| } |
| err = t.Execute(p, c) |
| if err != nil { |
| http.Error(c, err.String(), http.StatusInternalServerError) |
| } |
| } |
| |
| const lenPath = len("/view/") |
| |
| var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$") |
| |
| func getTitle(c *http.Conn, r *http.Request) (title string, err os.Error) { |
| title = r.URL.Path[lenPath:] |
| if !titleValidator.MatchString(title) { |
| http.NotFound(c, r) |
| err = os.NewError("Invalid Page Title") |
| } |
| return |
| } |
| |
| func main() { |
| http.HandleFunc("/view/", viewHandler) |
| http.HandleFunc("/edit/", editHandler) |
| http.HandleFunc("/save/", saveHandler) |
| http.ListenAndServe(":8080", nil) |
| } |