Go HTTP Server Responding to an HTTP Request using Templates
Example
Responses can be written to a http.ResponseWriter using templates in Go. This proves as a handy tool if you wish to create dynamic pages.
(To learn how Templates work in Go, please visit the Go Templates Documentation page.)
Continuing with a simple example to utilise the html/template to respond to an HTTP Request:
package main
import(
"html/template"
"net/http"
"log"
)
func main(){
http.HandleFunc("/",WelcomeHandler)
http.ListenAndServe(":8080",nil)
}
type User struct{
Name string
nationality string //unexported field.
}
func check(err error){
if err != nil{
log.Fatal(err)
}
}
func WelcomeHandler(w http.ResponseWriter, r *http.Request){
if r.Method == "GET"{
t,err := template.ParseFiles("welcomeform.html")
check(err)
t.Execute(w,nil)
}else{
r.ParseForm()
myUser := User{}
myUser.Name = r.Form.Get("entered_name")
myUser.nationality = r.Form.Get("entered_nationality")
t, err := template.ParseFiles("welcomeresponse.html")
check(err)
t.Execute(w,myUser)
}
}
Where, the contents of
welcomeform.htmlare:
<head>
<title> Help us greet you </title>
</head>
<body>
<form method="POST" action="/">
Enter Name: <input type="text" name="entered_name">
Enter Nationality: <input type="text" name="entered_nationality">
<input type="submit" value="Greet me!">
</form>
</body>
welcomeresponse.htmlare:
<head>
<title> Greetings, {{.Name}} </title>
</head>
<body>
Greetings, {{.Name}}.<br>
We know you are a {{.nationality}}!
</body>
Note:
-
Make sure that the
.htmlfiles are in the correct directory. -
When
http://localhost:8080/can be visited after starting the server. -
As it can be seen after submitting the form, the unexported nationality field of the struct could not be parsed by the template package, as expected.
