goanna/request.go
func (r *Request) FormValueOrDefault(key string, def string) string {
	val := r.FormValue(key)
	if val == "" {
		val = def
	}

	return val
}
func (r *Request) FormValueOrDefault(key string, def string) string {
	val := r.FormValue(key)
	if val == "" {
		val = def
	}

	return val
}
// FormValueOrDefault returns the result of Request.FormValue,
// and if the result is empty returns the default string