Passing address - but value is not updated (go chi middleware)

bundle := i18n.NewBundle(language.English)
	bundle.RegisterUnmarshalFunc("json", json.Unmarshal)

	lang := []string{"en-US", "fr"}

	for i := 0; i < len(lang); i++ {
		bundle.LoadMessageFile(fmt.Sprintf("json/%s.json", lang[I]))
	localizer := i18n.NewLocalizer(bundle, "en-US")
	appConfig := handler.AppConfig{T: t, Localizer: localizer}

	r.Use(middlewares.I18n(bundle, &appConfig))


func I18n(bundle *i18n.Bundle, appConfig *handler.AppConfig) func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		fn := func(w http.ResponseWriter, r *http.Request) {

			lang := r.URL.Query().Get("lang")

			if lang == "" {
				lang = "en-US"
				url, _ := common.FullUrl(r)

				q := url.Query()
				q.Add("lang", lang)
				url.RawQuery = q.Encode()

				http.Redirect(w, r, url.String(), http.StatusPermanentRedirect)

			accept := r.Header.Get("Accept-Language")
			fmt.Println("accept", accept)
			localizer := i18n.NewLocalizer(bundle, lang, accept)
			appConfig.Localizer = localizer
			appConfig.Lang = lang
			next.ServeHTTP(w, r)
		return http.HandlerFunc(fn)

inside some handlers...
fmt.Println(l.config.Lang) //it is empty - what is wrong here?


may you add some description beside the code?
Which packages are you using?

  • i18n
  • handler

where those packages come from ?

i18n => “
handler => custom package which contains the struct to hold the config

But it seems, by using middleware, it is not possible to change the value. Because everything compiled and I get the old data only. I don’t know exactly what happens.

Right now, I have created a new package to handle i18n (local package is also named as i18n. I have to think and rename it)

I have implemented the translate method for that package

func (i18 *I18n) Translate(text string) string {
	fmt.Println("Translate..", i18)
	localizer := i18n.NewLocalizer(i18.Bundle, i18.Lang)
	str, err := localizer.Localize(&i18n.LocalizeConfig{MessageID: text})
	if err != nil {
		return err.Error()

	return str

I pass the i18n struct to all my templates. Inside the templates, I call the function `translate

{{translate "login"}} //translated to Login
I made it working somehow.

//if you really need the code, I can create a simple go chi middleware and share the changing the value of a string. I tried that, That is also not working. (even after passing the address) Old value is printed

wondering if a better approach would be that the middleware adds the localizer to request’s Context instead of modifying the global appConfig.
I think thos would be a better approach to avoid that multiple requests change the global appConfigg in concurrent way

1 Like


I tried that approach. It is working good. with middleware’s context is the best solution.
Thanks a lot