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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 string) {
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 string) {
p, err := loadPage(title)
if err != nil {
p = &page{title: title}
}
renderTemplate(w, "edit", p)
}
func saveHandler(w http.ResponseWriter, r *http.Request, title string) {
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)
}
var templates = make(map[string]*template.Template)
func init() {
for _, tmpl := range []string{"edit", "view"} {
templates[tmpl] = template.MustParseFile(tmpl+".html", nil)
}
}
func renderTemplate(w http.ResponseWriter, tmpl string, p *page) {
err := templates[tmpl].Execute(p, w)
if err != nil {
http.Error(w, err.String(), http.StatusInternalServerError)
}
}
const lenPath = len("/view/")
var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
title := r.URL.Path[lenPath:]
if !titleValidator.MatchString(title) {
http.NotFound(w, r)
return
}
fn(w, r, title)
}
}
func main() {
http.HandleFunc("/view/", makeHandler(viewHandler))
http.HandleFunc("/edit/", makeHandler(editHandler))
http.HandleFunc("/save/", makeHandler(saveHandler))
http.ListenAndServe(":8080", nil)
}
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