hi guys,
I am looking to be able to integrate a select in a form but I have already a map interface of my which can be browsed to fill it I saw this tutorial on the web ici
but what does not appropriate to me is the var constant that stock all the html as I try to separate header footer content…
Is there any other way to proceed to achieve the same result?
thank you all for your technical support for newbies like me
1 Like
You can have your html code in a separate file (recommended) and fill it with values from your golang code using html/template
1 Like
even to populate my select?
1 Like
Yes. In fact, the web page you refrence use html/template.
<select> // for loop in html template example
{{range $key, $value := .}}
{{ $key }}
{{end}}
1 Like
OK I see it’s the syntax that is problematic tell me if I’m in the right
package main
import (
"net/http"
"html/template"
)
var fruits = map[string]interface{}{
"Apple": "apple",
"Orange": "orange",
"Pear": "pear",
"Grape": "grape",
}
func handler(w http.ResponseWriter, r *http.Request) {
t, _ := template.ParseFiles("view.html") //setp 1
t.Execute(w, fruits) //step 2
}
func main() {
server := http.Server{
Addr: "127.0.0.1:8080",
}
http.HandleFunc("/view", handler)
server.ListenAndServe()
}
/htmlcode for view.html
<html>
<head>
<title>First Program</title>
</head>
<body>
<select>{{range $ key, $ value: =. Fruits}} <option>{{$ key}} </option></select>
{{end}}
</body>
does it seem to you that I do not take it well?
1 Like
Something like this ::
package main
import (
"net/http"
"html/template"
)
var fruits = map[string]interface{}{
"Apple": "apple",
"Orange": "orange",
"Pear": "pear",
"Grape": "grape",
}
func Handler(w http.ResponseWriter, r *http.Request) {
t, err := template.ParseFiles("view.html")
if err != nil {
panic(err)
}
t.Execute(w, fruits)
}
func main() {
http.HandleFunc("/view", Handler)
http.ListenAndServe(":8080", nil)
}
<html>
<head>
<title>First Program</title>
</head>
<body>
<select>
{{range $key, $value : =.Fruits }}
<option>{{ $key}}</option>
{{end}}
</select>
</body>
</html>
2 Likes
in the case where we have more selects how we indetify them in the ranges.
because if I put fruit after the point as in the example the selection is empty
1 Like
You need to have two values in your select. One for the key and the value to be show for the option.
In this case you have got a map so tke key of the map could be used as key of the option.
The value could be a string expression from the data in the map.
To get an option selected by defualt add the selected=“selected” clause to the option you want to appears selected.
1 Like
ok this is my html
<select>
{{range $key, $value := . fruits}}
<option value="{{ $value }}">{{ $key }}</option>
makes the selection empty unless I remove fruit I do not understand how to call fruti because if you have more select it is not functional
package main
import (
"html/template"
"net/http"
)
var fruits = map[string]interface{}{
"Apple": "apple",
"Orange": "orange",
"Pear": "pear",
"Grape": "grape",
}
func handler(w http.ResponseWriter, r *http.Request) {
t, err := template.ParseFiles("templates/view.html")
if err != nil {
panic(err)
}
t.Execute(w, fruits)
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
thank you for your patience and your explanation
1 Like
Maybe the parses is not understading your template. Change to
<select>
{{- range $key, $value := .}}
<option value="{{ $key }}">{{ $value }}</option>
{{- end}}
</select>
Also generate the output to StdOut to check if everything is right
t.Execute(os.Stdout, fruits)
t.Execute(w, fruits)
1 Like
Hi Yamil_Bracho,
i tested but it does not work
if I do not fruit this function but if I have more model like his how to know what he will take?
this work
<select>
{{- range $key, $value := .}}
<option value="{{ $key }}">{{ $value }}</option>
{{- end}}
</select>
doesnt work why?
<select>
{{- range $key, $value := .fruits}}
<option value="{{ $key }}">{{ $value }}</option>
{{- end}}
</select>
1 Like
OK it works but like her. I do not know if it’s the right method
<select>
{{range .Fruits}}
<option value="{{ .Name }}">{{ .Values }}</option>
{{end}}
</select>
so I do not use the interface map
package main
import (
"html/template"
"net/http"
)
type Fruit struct {
Name string
Values string
}
type Data struct {
Name string
Fruits []Fruit
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
func handler(w http.ResponseWriter, r *http.Request) {
t, err := template.ParseFiles("templates/view.html")
if err != nil {
panic(err)
}
//t.Execute(os.Stdout, Data)
t.Execute(w, Data{
Fruits: []Fruit{
Fruit{"Apple", "apple"},
Fruit{"Orange", "orange"},
},
})
}
how to get the same result with an interface map anwer not easy
1 Like
You can use a map of interface without problems. What made easier things for you is group all the vars you would need in a structure. For example:
iewData := struct {
Fruits map[string]interface{}
}{
fruits,
}
t.Execute(os.Stdout, viewData)
t.Execute(w, viewData)
And in your template
<select>
{{- range $key, $value := .Fruits}}
<option value="{{ $key }}">{{ $value }}</option>
{{- end}}
</select>
1 Like
salut,
peux tu me montrer un exemple plus complet sur golang play par exemple car le je vois pas trop l’implentation
1 Like
Certainly.
HTML
<!DOCTYPE html>
<html lang=“en”>
<head>
<meta charset=“UTF-8”>
<meta name=“viewport” content=“width=device-width, initial-scale=1.0”>
<meta http-equiv=“X-UA-Compatible” content=“ie=edge”>
<title>Document</title>
</head>
<body>
Fruits:
<select>
{{- range $key, $value := .Fruits}}
<option value="{{ $key }}">{{ $value }}</option>
{{- end}}
</select>
</body>
</html>
Go
`package main
import (
“html/template”
“net/http”
“os”
)
var fruits = map[string]interface{}{
“Apple”: “apple”,
“Orange”: “orange”,
“Pear”: “pear”,
“Grape”: “grape”,
}
func handler(w http.ResponseWriter, r *http.Request) {
t, err := template.ParseFiles(“templates/view.html”)
if err != nil {
panic(err)
}
viewData := struct {
Fruits map[string]interface{}
}{
fruits,
}
//t.Execute(os.Stdout, viewData)
t.Execute(w, viewData)
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
`
1 Like
super merci beaucoup pour l exemple je comprend mieux
1 Like
Good thing it was helpful … 
1 Like
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