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|
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(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.String(), http.StatusInternalServerError)
return
}
http.Redirect(w, r, "/view/"+title, http.StatusFound)
}
func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
t, err := template.ParseFile(tmpl+".html")
if err != nil {
http.Error(w, err.String(), http.StatusInternalServerError)
return
}
err = t.Execute(w, p)
if err != nil {
http.Error(w, err.String(), http.StatusInternalServerError)
}
}
const lenPath = len("/view/")
var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
func getTitle(w http.ResponseWriter, r *http.Request) (title string, err os.Error) {
title = r.URL.Path[lenPath:]
if !titleValidator.MatchString(title) {
http.NotFound(w, 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)
}
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