Very basic Golang library for i18n. There are others that do the job, but this is my take on the problem.

1. Storing messages in JSON files.
2. Support for nested declarations.
3. Detecting language based on Request headers.
4. Very simple to use.

1. Import Lingo into your project

     import "github.com/kortem/lingo"

2. Create a dir to store translations, and write them in JSON files named [locale].json. For example:

     en_US.json
     sr_RS.json
     de.json
     ...
   

   You can write nested JSON too.

     {
       "main.title" : "CutleryPlus",
       "main.subtitle" : "Knives that put cut in cutlery.",
       "menu" : {
         "home" : "Home",
         "products": {
           "self": "Products",
           "forks" : "Forks",
           "knives" : "Knives",
           "spoons" : "Spoons"
         },
       }
     }

3. Initialize a Lingo like this:

     l := lingo.New("default_locale", "path/to/translations/dir")

4. Get bundle for specific locale via either string:

     t1 := l.TranslationsForLocale("en_US")
     t2 := l.TranslationsForLocale("de_DE")

   This way Lingo will return the bundle for specific locale, or default if given is not found. Alternatively (or primarily), you can get it with *http.Request:

     t := l.TranslationsForRequest(req)

   This way Lingo finds best suited locale via Accept-Language header, or if there is no match, returns default. Accept-Language header is set by the browser, so basically it will serve the language the user has set to his browser.

5. Once you get T instance just fire away!

     r1 := t1.Value("main.subtitle")
     // "Knives that put cut in cutlery."
     r1 := t2.Value("main.subtitle")
     // "Messer, die legte in Besteck geschnitten."
     r3 := t1.Value("menu.products.self")
     // "Products"
     r5 := t1.Value("error.404", req.URL.Path)
     // "Page index.html not found!"

I regard this little library as feature-complete, but if you have an idea on how to improve it, feel free to create issues. Also, pull requests are welcome. Enjoy!