Implement gobuffalo#723 localized views

middleware/i18n/i18n.go

@@ -2,6 +2,7 @@ package i18n
 
 import (
 	"log"
+	"strings"
 
 	"github.com/gobuffalo/buffalo"
 	"github.com/gobuffalo/packr"
@@ -21,7 +22,7 @@ type LanguageFinder func(*Translator, buffalo.Context) []string
 type Translator struct {
 	// Box - where are the files?
 	Box packr.Box
-	// DefaultLanguage - default is "en-US"
+	// DefaultLanguage - default is passed as a parameter on New.
 	DefaultLanguage string
 	// CookieName - name of the cookie to find the desired language.
 	// default is "lang"
@@ -32,6 +33,8 @@ type Translator struct {
 	// HelperName - name of the view helper. default is "t"
 	HelperName     string
 	LanguageFinder LanguageFinder
+	// LocalizedViews - enable localized views feature
+	LocalizedViews bool
 }
 
 // Load translations from the t.Box.
@@ -63,6 +66,7 @@ func New(box packr.Box, language string) (*Translator, error) {
 		SessionName:     "lang",
 		HelperName:      "t",
 		LanguageFinder:  defaultLanguageFinder,
+		LocalizedViews:  false,
 	}
 	return t, t.Load()
 }
@@ -92,6 +96,9 @@ func (t *Translator) Middleware() buffalo.MiddlewareFunc {
 			// set languages in context, if not set yet
 			if langs := c.Value("languages"); langs == nil {
 				c.Set("languages", t.LanguageFinder(t, c))
+				if t.LocalizedViews {
+					c.Set("templateSuffixes", c.Value("languages"))
+				}
 			}
 
 			// set translator
@@ -157,10 +164,26 @@ func defaultLanguageFinder(t *Translator, c buffalo.Context) []string {
 	// try to get the language from a header:
 	acceptLang := r.Header.Get("Accept-Language")
 	if acceptLang != "" {
-		langs = append(langs, acceptLang)
+		langs = append(langs, parseAcceptLanguage(acceptLang)...)
 	}
 
-	// try to get the language from the session:
+	// finally set the default app language as fallback
 	langs = append(langs, t.DefaultLanguage)
 	return langs
 }
+
+// Inspired from https://siongui.github.io/2015/02/22/go-parse-accept-language/
+// Parse an Accept-Language string to get usable lang values for i18n system
+func parseAcceptLanguage(acptLang string) []string {
+	var lqs []string
+
+	langQStrs := strings.Split(acptLang, ",")
+	for _, langQStr := range langQStrs {
+		trimedLangQStr := strings.Trim(langQStr, " ")
+
+		langQ := strings.Split(trimedLangQStr, ";")
+		lq := langQ[0]
+		lqs = append(lqs, lq)
+	}
+	return lqs
+}

middleware/i18n/i18n_test.go

@@ -16,7 +16,7 @@ type User struct {
 	LastName  string
 }
 
-func app() *buffalo.App {
+func app(localizedViews bool) *buffalo.App {
 	app := buffalo.New(buffalo.Options{})
 
 	r := render.New(render.Options{
@@ -28,6 +28,9 @@ func app() *buffalo.App {
 	if err != nil {
 		log.Fatal(err)
 	}
+	if localizedViews {
+		t.LocalizedViews = true
+	}
 	app.Use(t.Middleware())
 	app.GET("/", func(c buffalo.Context) error {
 		return c.Render(200, r.HTML("index.html"))
@@ -42,21 +45,24 @@ func app() *buffalo.App {
 		c.Set("Users", usersList)
 		return c.Render(200, r.HTML("format.html"))
 	})
+	app.GET("/localized", func(c buffalo.Context) error {
+		return c.Render(200, r.HTML("localized_view.html"))
+	})
 	return app
 }
 
 func Test_i18n(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	res := w.Request("/").Get()
 	r.Equal("Hello, World!\n", res.Body.String())
 }
 
 func Test_i18n_fr(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	req := w.Request("/")
 	// Set language as "french"
 	req.Headers["Accept-Language"] = "fr-fr"
@@ -67,15 +73,15 @@ func Test_i18n_fr(t *testing.T) {
 func Test_i18n_plural(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	res := w.Request("/plural").Get()
 	r.Equal("Hello, alone!\nHello, 5 people!\n", res.Body.String())
 }
 
 func Test_i18n_plural_fr(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	req := w.Request("/plural")
 	// Set language as "french"
 	req.Headers["Accept-Language"] = "fr-fr"
@@ -86,18 +92,39 @@ func Test_i18n_plural_fr(t *testing.T) {
 func Test_i18n_format(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	res := w.Request("/format").Get()
 	r.Equal("Hello Mark!\n\n\t* Mr. Mark Bates\n\n\t* Mr. Chuck Berry\n", res.Body.String())
 }
 
 func Test_i18n_format_fr(t *testing.T) {
 	r := require.New(t)
 
-	w := willie.New(app())
+	w := willie.New(app(false))
 	req := w.Request("/format")
 	// Set language as "french"
 	req.Headers["Accept-Language"] = "fr-fr"
 	res := req.Get()
 	r.Equal("Bonjour Mark !\n\n\t* M. Mark Bates\n\n\t* M. Chuck Berry\n", res.Body.String())
 }
+
+func Test_i18n_Localized_View(t *testing.T) {
+	r := require.New(t)
+
+	w := willie.New(app(true))
+	// Test with complex Accept-Language
+	req := w.Request("/localized")
+	req.Headers["Accept-Language"] = "en-US,en;q=0.5"
+	res := req.Get()
+	r.Equal("Hello!\n", res.Body.String())
+
+	// Test priority
+	req.Headers["Accept-Language"] = "fr,en"
+	res = req.Get()
+	r.Equal("Bonjour !\n", res.Body.String())
+
+	// Test fallback
+	req.Headers["Accept-Language"] = "ru"
+	res = req.Get()
+	r.Equal("Default\n", res.Body.String())
+}

middleware/i18n/templates/localized_view.html

@@ -0,0 +1 @@
+Default

middleware/i18n/templates/localized_view_en.html

@@ -0,0 +1 @@
+Hello!

middleware/i18n/templates/localized_view_fr.html

@@ -0,0 +1 @@
+Bonjour !

render/template.go

@@ -61,6 +61,21 @@ func (s templateRenderer) exec(name string, data Data) (template.HTML, error) {
 		}
 	}
 
+	// Try to use a suffixed version first (if provided)
+	if suffixes, ok := data["templateSuffixes"].([]string); ok {
+		ext := filepath.Ext(name)
+		rawName := strings.TrimSuffix(name, ext)
+
+		for _, suffix := range suffixes {
+			candidateName := rawName + "_" + suffix + ext
+			if s.TemplatesBox.Has(candidateName) {
+				// Replace name with the existing suffixed version
+				name = candidateName
+				break
+			}
+		}
+	}
+
 	source, err := s.TemplatesBox.MustBytes(name)
 	if err != nil {
 		return "", err

render/template_test.go

@@ -215,3 +215,46 @@ func Test_AssetPathManifestCorrupt(t *testing.T) {
 		os.Remove(tmpFile.Name())
 	}
 }
+
+func Test_Suffixes(t *testing.T) {
+	r := require.New(t)
+
+	tPath, err := ioutil.TempDir("", "test")
+	r.NoError(err)
+
+	tmpFile, err := os.Create(filepath.Join(tPath, "test"))
+	r.NoError(err)
+	defer os.Remove(tmpFile.Name())
+
+	tmpFileSuffixed, err := os.Create(tmpFile.Name() + "_alt")
+	r.NoError(err)
+	defer os.Remove(tmpFileSuffixed.Name())
+
+	_, err = tmpFile.Write([]byte("normal"))
+	r.NoError(err)
+
+	_, err = tmpFileSuffixed.Write([]byte("suffixed"))
+	r.NoError(err)
+
+	type ji func(string, ...string) render.Renderer
+
+	table := []ji{
+		render.New(render.Options{
+			TemplatesBox: packr.NewBox(tPath),
+		}).Template,
+	}
+
+	for _, j := range table {
+		re := j("foo/bar", filepath.Base(tmpFile.Name()))
+		r.Equal("foo/bar", re.ContentType())
+		bb1 := &bytes.Buffer{}
+		err = re.Render(bb1, render.Data{})
+		r.NoError(err)
+		r.Equal("normal", strings.TrimSpace(bb1.String()))
+
+		bb2 := &bytes.Buffer{}
+		err = re.Render(bb2, render.Data{"templateSuffixes": []string{"alt"}})
+		r.NoError(err)
+		r.Equal("suffixed", strings.TrimSpace(bb2.String()))
+	}
+}