i18n

Package i18n provides internationalization utilities.

Installing

1. Get package:

   go get -u github.com/gowww/i18n

2. Import it in your code with dependencies:

   import (
   	"github.com/gowww/i18n"
   	"golang.org/x/text/language"
   )

Usage

Make the Locales (string to string, for each language):

locales := i18n.Locales{
	language.English: {
		"hello": "Hello!",
	},
	language.French: {
		"hello": "Bonjour !",
	},
}

You're ready to make a handler with these locales, the default locale and the request parsers (matching the client language) you want to use.

Inside a handler, use RequestTranslator to get the translator containing the best locale for client.
Use Translator.T, Translator.THTML, Translator.Tn or Translator.TnHTML to retrieve the translation from a key.

i18n.RequestTranslator(r).T("hello")

So, to wrap an http.Handler, use Handle:

mux := http.NewServeMux()

mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
	rt := i18n.RequestTranslator(r)
	fmt.Fprint(w, rt.T("hello"))
})

http.ListenAndServe(":8080", i18n.Handle(mux, locales, language.English, i18n.ParseAcceptLanguage))

To wrap an http.HandlerFunc, use HandleFunc:

http.Handle("/", i18n.HandleFunc(func(w http.ResponseWriter, r *http.Request) {
	rt := i18n.RequestTranslator(r)
	fmt.Fprint(w, rt.T("hello"))
}, locales, language.English, i18n.ParseAcceptLanguage))

http.ListenAndServe(":8080", nil)

Functioning

1. The i18n handler receives a request.
2. It must solve one question: what's the best locale for the user?
3. To determine this, it has one or more Parsers (the ones you provided). They have their own way to find a result.
4. So the i18n handler questions each parser (in the same order you provided them) and each one gives no, one or more potential locale.
5. The i18n handler takes the first locale having a certains confidence threshold, adds a translator to the request context and serves your own handler.

References

• Proposal: Localization support in Go
• Accept-Language used for locale setting — W3C
• Multi-regional and multilingual sites — Google
• Use hreflang for language and regional URLs — Google
• New markup for multilingual content — Google
• Crawling and indexing of locale-adaptive pages — Google
• SEO for multilingual sites: language-specific results without changing URL?
• Geotargeting based on IP address is broken