Web development with Go; Minimal example

main.go

package main

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
)

type User struct {
	FirstName string `json:"first_name"`
	LastName  string `json:"last_name"`
	Email     string `json:"email"`
}

var users = []User{
	{"Martin", "Helmich", "martin@example.com"},
	{"Max", "Mustermann", "max@example.com"},
}

func main() {
	http.HandleFunc("/users.json", func(res http.ResponseWriter, req *http.Request) {
		res.Header().Set("Content-Type", "application/json;charset=utf-8")
		json.NewEncoder(res).Encode(users)
	})

	http.HandleFunc("/users.html", func(res http.ResponseWriter, req *http.Request) {
		t, err := template.ParseFiles("userlist.html")
		if err != nil {
			res.WriteHeader(500)
			fmt.Fprintf(res, "Fehler beim Laden des Templates: %s", err)
		} else {
			t.Execute(res, users)
		}
	})

	http.ListenAndServe(":8080", nil)
}

userlist.html

<h1>Nutzer</h1>

<ul>
    {{ range . }}
        <li><a href="mailto:{{ .Email }}">{{ .FirstName }} {{ .LastName }}</a></li>
    {{ end }}
</ul>