Go Examples #golang #go #code

wiki.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strings"
)

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 listHandler(w http.ResponseWriter, r *http.Request) {
	files, _ := ioutil.ReadDir(".")
	for _, file := range files {
		if strings.HasSuffix(file.Name(), ".txt") {
			page := strings.TrimSuffix(file.Name(), ".txt")
			fmt.Fprintf(w, "<div><a href=\"/view/%s\">%[1]s</a></div>", page)
		}
	}
}

func viewHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/view/"):]
	p, _ := loadPage(title)
	fmt.Fprintf(w, "<h1>%s</h1><div>%s</div><div><a href=\"/edit/%s\">edit?</a></div>", p.Title, p.Body, title)
}

func saveHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/view/"):]
	if err := r.ParseForm(); err != nil {
		fmt.Fprintf(w, "ParseForm() err: %v", err)
		return
	}
	body := r.FormValue("body")
	p := &Page{Title: title, Body: []byte(body)}
	if err := p.save(); err != nil {
		fmt.Fprintf(w, "save error: %v", err)
	} else {
		http.Redirect(w, r, "/view/"+title, http.StatusMovedPermanently)
	}
}

func editHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/view/"):]
	p, err := loadPage(title)
	if err != nil {
		p = &Page{Title: title, Body: []byte("")}
	}
	fmt.Fprintf(w, "<h1>Editing %s</h1><form action=\"/save/%[1]s\" method=\"POST\"><textarea name=\"body\">%s</textarea><br><input type=\"submit\" value=\"Save\"></form>", p.Title, string(p.Body))
}

func main() {
	http.HandleFunc("/", listHandler)
	http.HandleFunc("/view/", viewHandler)
	http.HandleFunc("/edit/", editHandler)
	http.HandleFunc("/save/", saveHandler)
	log.Fatal(http.ListenAndServe(":8080", nil))
}