Create custom helpers for HTML and XML templates in Go

custom_template_functions.go

content, err = ioutil.ReadFile("templates/rss.xml")
  if err != nil {
    panic(err)
  }

//Custom template helpers
  fm := template.FuncMap{"number": func(n int) string {
    return strconv.Itoa(n)
  }, "float": func(f float64) string {
    return strconv.FormatFloat(f, 'f', -1, 64)
  }, "objectid": func(id bson.ObjectId) string {
    return id.Hex()
  }}
  
  type Feed struct {
    Name string
    Item []string
  }
  var feed Feed = new Feed{Name: "Custom Feed"}
  
  t, err := template.New("rss").Funcs(fm).Parse(string(content))
  if err != nil {
    panic(err)
  }
  
  // The template output
  buffer := bytes.NewBuffer(nil)
  writer := io.Writer(buffer)
  t.Execute(writer, &feed)