I know that in go templates I can call function named add for expression like 1 + 1. But how named function for expression like 2 - 1?
You could always define such a function:
package main
import (
"html/template"
"net/http"
"strconv"
)
var funcMap = template.FuncMap{
"minus": minus,
}
const tmpl = `
<html><body>
<div>
<span>{{minus 1 2}}</span>
</div>
</body></html>`
var tmplGet = template.Must(template.New("").Funcs(funcMap).Parse(tmpl))
func minus(a, b int64) string {
return strconv.FormatInt(a-b, 10)
}
func getPageHandler(w http.ResponseWriter, r *http.Request) {
if err := tmplGet.Execute(w, nil); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
func main() {
http.HandleFunc("/", getPageHandler)
http.ListenAndServe(":8080", nil)
}
There is no add function included by default. You can however, easily write such functions yourself. For example:
tmpl := template.Must(template.New("").Funcs(template.FuncMap{
"minus": func(a, b int) int {
return a - b
},
}).Parse("{{ minus 5 2 }}"))
tmpl.Execute(os.Stdout, nil)