I18n (internationalisation) support closes #249

generators/newapp/templates/actions/app.go.tmpl

@@ -1,8 +1,10 @@
 package actions
 
 import (
+  "log"
   "github.com/gobuffalo/buffalo"
   "github.com/gobuffalo/buffalo/middleware"
+  "github.com/gobuffalo/buffalo/middleware/i18n"
   {{ if .withPop }}
   "{{.modelsPath}}"
   {{ end }}
@@ -35,6 +37,13 @@ func App() *buffalo.App {
     app.Use(middleware.PopTransaction(models.DB))
     {{ end }}
 
+		// Setup and use translations:
+		t, err := i18n.New(packr.NewBox("../locales"), "en-US")
+		if err != nil {
+			log.Fatal(err)
+		}
+		app.Use(t.Middleware())
+
     app.GET("/", HomeHandler)
 
     app.ServeFiles("/assets", packr.NewBox("../public/assets"))

generators/newapp/templates/locales/all.en-us.yaml.tmpl

@@ -0,0 +1,2 @@
+- id: welcome_greeting
+  translation: "Welcome to Buffalo (EN)"

generators/newapp/templates/templates/index.html.tmpl

@@ -3,7 +3,7 @@
     <img src="/assets/images/logo.svg" alt="" />
   </div>
   <div class="col-md-10">
-    <h1>Welcome to Buffalo! [v{{.version}}]</h1>
+    <h1><%= t("welcome_greeting") %> [v{{.version}}]</h1>
     <h2>
       <a href="https://github.com/gobuffalo/buffalo"><i class="fa fa-github" aria-hidden="true"></i> https://github.com/gobuffalo/buffalo</a>
     </h2>

middleware/i18n/i18n.go

@@ -0,0 +1,126 @@
+package i18n
+
+import (
+	"log"
+
+	"github.com/gobuffalo/buffalo"
+	"github.com/gobuffalo/packr"
+	"github.com/gobuffalo/plush"
+	"github.com/nicksnyder/go-i18n/i18n"
+	"github.com/nicksnyder/go-i18n/i18n/language"
+	"github.com/nicksnyder/go-i18n/i18n/translation"
+	"github.com/pkg/errors"
+)
+
+// LanguageFinder can be implemented for custom finding of search
+// languages. This can be useful if you want to load a user's langugage
+// from something like a database. See Middleware() for more information
+// on how the default implementation searches for languages.
+type LanguageFinder func(*Translator, buffalo.Context) []string
+
+// Translator for handling all your i18n needs.
+type Translator struct {
+	// Box - where are the files?
+	Box packr.Box
+	// DefaultLanguage - default is "en-US"
+	DefaultLanguage string
+	// CookieName - name of the cookie to find the desired language.
+	// default is "lang"
+	CookieName string
+	// HelperName - name of the view helper. default is "t"
+	HelperName     string
+	LanguageFinder LanguageFinder
+}
+
+// Load translations from the t.Box.
+func (t *Translator) Load() error {
+	return t.Box.Walk(func(path string, f packr.File) error {
+		b, err := t.Box.MustBytes(path)
+		if err != nil {
+			log.Fatal(err)
+			return errors.WithStack(err)
+		}
+		return i18n.ParseTranslationFileBytes(path, b)
+	})
+}
+
+// AddTranslation directly, without using a file. This is useful if you wish to load translations
+// from a database, instead of disk.
+func (t *Translator) AddTranslation(lang *language.Language, translations ...translation.Translation) {
+	i18n.AddTranslation(lang, translations...)
+}
+
+// New Translator. Requires a packr.Box that points to the location
+// of the translation files, as well as a default language. This will
+// also call t.Load() and load the translations from disk.
+func New(box packr.Box, language string) (*Translator, error) {
+	t := &Translator{
+		Box:             box,
+		DefaultLanguage: language,
+		CookieName:      "lang",
+		HelperName:      "t",
+		LanguageFinder:  defaultLanguageFinder,
+	}
+	return t, t.Load()
+}
+
+// Middleware for loading the translations for the language(s)
+// selected. By default languages are loaded in the following order:
+//
+// Cookie - "lang"
+// Header - "Accept-Language"
+// Default - "en-US"
+//
+// These values can be changed on the Translator itself. In development
+// model the translation files will be reloaded on each request.
+func (t *Translator) Middleware() buffalo.MiddlewareFunc {
+	return func(next buffalo.Handler) buffalo.Handler {
+		return func(c buffalo.Context) error {
+
+			// in development reload the translations
+			if c.Value("env").(string) == "development" {
+				err := t.Load()
+				if err != nil {
+					return err
+				}
+			}
+
+			langs := t.LanguageFinder(t, c)
+
+			c.Set("languages", langs)
+
+			// set up the helper function for the views:
+			c.Set(t.HelperName, func(s string, help plush.HelperContext) (string, error) {
+				T, err := i18n.Tfunc(langs[0], langs[1:]...)
+				if err != nil {
+					return "", err
+				}
+				return T(s), nil
+			})
+			return next(c)
+		}
+	}
+}
+
+func defaultLanguageFinder(t *Translator, c buffalo.Context) []string {
+	langs := []string{}
+
+	r := c.Request()
+
+	// try to get the language from a cookie:
+	if cookie, err := r.Cookie(t.CookieName); err == nil {
+		if cookie.Value != "" {
+			langs = append(langs, cookie.Value)
+		}
+	}
+
+	// try to get the language from a header:
+	acceptLang := r.Header.Get("Accept-Language")
+	if acceptLang != "" {
+		langs = append(langs, acceptLang)
+	}
+
+	// try to get the language from the session:
+	langs = append(langs, t.DefaultLanguage)
+	return langs
+}

middleware/i18n/i18n_test.go

@@ -0,0 +1,39 @@
+package i18n
+
+import (
+	"log"
+	"testing"
+
+	"github.com/gobuffalo/buffalo"
+	"github.com/gobuffalo/buffalo/render"
+	"github.com/gobuffalo/packr"
+	"github.com/markbates/willie"
+	"github.com/stretchr/testify/require"
+)
+
+func app() *buffalo.App {
+	app := buffalo.Automatic(buffalo.Options{})
+
+	r := render.New(render.Options{
+		TemplatesBox: packr.NewBox("./templates"),
+	})
+
+	// Setup and use translations:
+	t, err := New(packr.NewBox("./locales"), "en-US")
+	if err != nil {
+		log.Fatal(err)
+	}
+	app.Use(t.Middleware())
+	app.GET("/", func(c buffalo.Context) error {
+		return c.Render(200, r.HTML("index.html"))
+	})
+	return app
+}
+
+func Test_i18n(t *testing.T) {
+	r := require.New(t)
+
+	w := willie.New(app())
+	res := w.Request("/").Get()
+	r.Equal("Hello, World!\n", res.Body.String())
+}

middleware/i18n/locales/test.en-us.yaml

@@ -0,0 +1,2 @@
+- id: greeting
+  translation: "Hello, World!"

middleware/i18n/templates/index.html

@@ -0,0 +1 @@
+<%= t("greeting") %>