simple txt copy via web

main.go

package main

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"net/http"
)

var txt = ""
const html = `<div><textarea style="width:100%" id="t">{{.Text}}</textarea></div>
<div><button id="b">update</button></div>
<script>
const t = document.querySelector('#t');
const b = document.querySelector('#b');
b.addEventListener('click', ()=>{
    fetch('/msg', {
  method: 'post',
  body: t.value});
});
</script>
`
func main(){
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Content-Type", "text/html")
		t, err := template.New("webpage").Parse(html)
		if(err != nil){
			fmt.Println(w, err)
			return;
		}
		data := struct{
			Text string
		}{
			Text: txt,
		}
		err = t.Execute(w, data)
		if(err != nil){
			fmt.Println(w, err)
			return;
		}
	})
	http.HandleFunc("/msg", func(w http.ResponseWriter, r *http.Request) {
		if(r.Method == "POST"){
			defer r.Body.Close();
			b, _ := ioutil.ReadAll(r.Body)
			txt = string(b)
			return
		}

		fmt.Fprintln(w, txt)
	})

	s := &http.Server{
		Addr: ":1999",
	}
	s.ListenAndServe()
}