i18n: import lingo

10 files changed, 584 insertions, 0 deletions

diff --git a/i18n/LICENSE.md b/i18n/LICENSE.md
new file mode 100644
index 0000000..c72833f
--- /dev/null
+++ b/i18n/LICENSE.md
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Dusan Lilic
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/i18n/README.md b/i18n/README.md
new file mode 100644
index 0000000..c260ea2
--- /dev/null
+++ b/i18n/README.md
@@ -0,0 +1,79 @@
+lingo
+=====
+
+Very basic Golang library for i18n. There are others that do the job, but this is my take on the problem.
+
+Features:
+---------
+1. Storing messages in JSON files.
+2. Support for nested declarations.
+2. Detecting language based on Request headers.
+3. Very simple to use.
+
+Usage:
+------
+  1. Import Lingo into your project
+
+      ```go
+        import "github.com/kortem/lingo"
+      ```
+  1. 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.
+      ```json
+        {
+          "main.title" : "CutleryPlus",
+          "main.subtitle" : "Knives that put cut in cutlery.",
+          "menu" : {
+            "home" : "Home",
+            "products": {
+              "self": "Products",
+              "forks" : "Forks",
+              "knives" : "Knives",
+              "spoons" : "Spoons"
+            },
+          }
+        }
+      ```
+  2. Initialize a Lingo like this:
+
+      ```go
+        l := lingo.New("default_locale", "path/to/translations/dir")
+      ```
+
+  3. Get bundle for specific locale via either `string`:
+
+      ```go
+        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`:
+
+      ```go
+        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.
+  4. Once you get T instance just fire away!
+
+      ```go
+        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!"
+      ```
+
+Contributions:
+-----
+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!
diff --git a/i18n/legal.go b/i18n/legal.go
new file mode 100644
index 0000000..7f68dff
--- /dev/null
+++ b/i18n/legal.go
@@ -0,0 +1,29 @@
+package i18n
+
+import "go4.org/legal"
+
+func init() {
+	legal.RegisterLicense(`i18n library of this software copyright:
+
+The MIT License (MIT)
+
+Copyright (c) 2014 Dusan Lilic
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.`)
+}
diff --git a/i18n/lingo.go b/i18n/lingo.go
new file mode 100644
index 0000000..4824c01
--- /dev/null
+++ b/i18n/lingo.go
@@ -0,0 +1,132 @@
+package i18n
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// L represents Lingo bundle, containing map of all Ts by locale,
+// as well as default locale and list of supported locales
+type L struct {
+	bundle    map[string]T
+	deflt     string
+	supported []Locale
+}
+
+func (l *L) exists(locale string) bool {
+	_, exists := l.bundle[locale]
+	return exists
+}
+
+// TranslationsForRequest will get the best matched T for given
+// Request. If no T is found, returns default T
+func (l *L) TranslationsForRequest(r *http.Request) T {
+	locales := GetLocales(r)
+	for _, locale := range locales {
+		t, exists := l.bundle[locales[0].Name()]
+		if exists {
+			return t
+		}
+		for _, sup := range l.supported {
+			if locale.Lang == sup.Lang {
+				return l.bundle[sup.Name()]
+			}
+		}
+	}
+	return l.bundle[l.deflt]
+}
+
+// TranslationsForLocale will get the T for specific locale.
+// If no locale is found, returns default T
+func (l *L) TranslationsForLocale(locale string) T {
+	t, exists := l.bundle[locale]
+	if exists {
+		return t
+	}
+	return l.bundle[l.deflt]
+}
+
+// T represents translations map for specific locale
+type T struct {
+	transl map[string]interface{}
+}
+
+// Value traverses the translations map and finds translation for
+// given key. If no translation is found, returns value of given key.
+func (t T) Value(key string, args ...string) string {
+	if t.exists(key) {
+		res, ok := t.transl[key].(string)
+		if ok {
+			return t.parseArgs(res, args)
+		}
+	}
+	ksplt := strings.Split(key, ".")
+	for i := range ksplt {
+		k1 := strings.Join(ksplt[0:i], ".")
+		k2 := strings.Join(ksplt[i:len(ksplt)], ".")
+		if t.exists(k1) {
+			newt := &T{
+				transl: t.transl[k1].(map[string]interface{}),
+			}
+			return newt.Value(k2, args...)
+		}
+	}
+	return key
+}
+
+// parseArgs replaces the argument placeholders with given arguments
+func (t T) parseArgs(value string, args []string) string {
+	res := value
+	for i := 0; i < len(args); i++ {
+		tok := "{" + strconv.Itoa(i) + "}"
+		res = strings.Replace(res, tok, args[i], -1)
+	}
+	return res
+}
+
+// exists checks if value exists for given key
+func (t T) exists(key string) bool {
+	_, ok := t.transl[key]
+	return ok
+}
+
+// New creates the Lingo bundle.
+// Params:
+// Default locale, to be used when requested locale
+// is not found.
+// Path, absolute or relative path to a folder where
+// translation .json files are kept
+func New(deflt, path string) *L {
+	files, _ := ioutil.ReadDir(path)
+	l := &L{
+		bundle:    make(map[string]T),
+		deflt:     deflt,
+		supported: make([]Locale, 0),
+	}
+	for _, f := range files {
+		fileName := f.Name()
+		dat, err := ioutil.ReadFile(path + "/" + fileName)
+		if err != nil {
+			log.Printf("Cannot read file %s, file corrupt.", fileName)
+			log.Printf("Error: %s", err)
+			continue
+		}
+		t := T{
+			transl: make(map[string]interface{}),
+		}
+		err = json.Unmarshal(dat, &t.transl)
+		if err != nil {
+			log.Printf("Cannot read file %s, invalid JSON.", fileName)
+			log.Printf("Error: %s", err)
+			continue
+		}
+		locale := strings.Split(fileName, ".")[0]
+		l.supported = append(l.supported, ParseLocale(locale))
+		l.bundle[locale] = t
+	}
+	return l
+}
diff --git a/i18n/lingo_test.go b/i18n/lingo_test.go
new file mode 100644
index 0000000..ca1f559
--- /dev/null
+++ b/i18n/lingo_test.go
@@ -0,0 +1,87 @@
+package i18n
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+)
+
+func TestLingo(t *testing.T) {
+	l := New("de_DE", "translations")
+	t1 := l.TranslationsForLocale("en_US")
+	r1 := t1.Value("main.subtitle")
+	r1Exp := "Knives that put cut in cutlery."
+	if r1 != r1Exp {
+		t.Errorf("Expected \""+r1Exp+"\", got %s", r1)
+		t.Fail()
+	}
+	r2 := t1.Value("home.title")
+	r2Exp := "Welcome to CutleryPlus!"
+	if r2 != r2Exp {
+		t.Errorf("Expected \""+r2Exp+"\", got %s", r2)
+		t.Fail()
+	}
+	r3 := t1.Value("menu.products.self")
+	r3Exp := "Products"
+	if r3 != r3Exp {
+		t.Errorf("Expected \""+r3Exp+"\", got %s", r3)
+		t.Fail()
+	}
+	r4 := t1.Value("menu.non.existant")
+	r4Exp := "non.existant"
+	if r4 != r4Exp {
+		t.Errorf("Expected \""+r4Exp+"\", got %s", r4)
+		t.Fail()
+	}
+	r5 := t1.Value("error.404", "idnex.html")
+	r5Exp := "Page idnex.html not found!"
+	if r5 != r5Exp {
+		t.Errorf("Expected \""+r5Exp+"\", got \"%s\"", r5)
+		t.Fail()
+	}
+}
+
+func TestLingoHttp(t *testing.T) {
+	l := New("en_US", "translations")
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		expected := r.Header.Get("Expected-Results")
+		t1 := l.TranslationsForRequest(r)
+		r1 := t1.Value("error.500")
+		if r1 != expected {
+			t.Errorf("Expected \""+expected+"\", got %s", r1)
+			t.Fail()
+		}
+	}))
+	defer srv.Close()
+	url, _ := url.Parse(srv.URL)
+
+	req1 := &http.Request{
+		Method: "GET",
+		Header: map[string][]string{
+			"Accept-Language":  {"sr, en-gb;q=0.8, en;q=0.7"},
+			"Expected-Results": {"Greska sa nase strane, pokusajte ponovo."},
+		},
+		URL: url,
+	}
+	req2 := &http.Request{
+		Method: "GET",
+		Header: map[string][]string{
+			"Accept-Language":  {"en-US, en-gb;q=0.8, en;q=0.7"},
+			"Expected-Results": {"Something is wrong on our side, please try again."},
+		},
+		URL: url,
+	}
+	req3 := &http.Request{
+		Method: "GET",
+		Header: map[string][]string{
+			"Accept-Language":  {"de-at, en-gb;q=0.8, en;q=0.7"},
+			"Expected-Results": {"Stimmt etwas nicht auf unserer Seite ist, versuchen Sie es erneut."},
+		},
+		URL: url,
+	}
+
+	http.DefaultClient.Do(req1)
+	http.DefaultClient.Do(req2)
+	http.DefaultClient.Do(req3)
+}
diff --git a/i18n/locale.go b/i18n/locale.go
new file mode 100644
index 0000000..6b4a793
--- /dev/null
+++ b/i18n/locale.go
@@ -0,0 +1,101 @@
+package i18n
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// Locale is locale value from the Accept-Language header in request
+type Locale struct {
+	Lang, Country string
+	Qual          float64
+}
+
+// Name returns the locale value in 'lang' or 'lang_country' format
+// eg: de_DE, en_US, gb
+func (l *Locale) Name() string {
+	if len(l.Country) > 0 {
+		return l.Lang + "_" + l.Country
+	}
+	return l.Lang
+}
+
+// ParseLocale creates a Locale from a locale string
+func ParseLocale(locale string) Locale {
+	locsplt := strings.Split(locale, "_")
+	resp := Locale{}
+	resp.Lang = locsplt[0]
+	if len(locsplt) > 1 {
+		resp.Country = locsplt[1]
+	}
+	return resp
+}
+
+const (
+	acceptLanguage = "Accept-Language"
+)
+
+func supportedLocales(alstr string) []Locale {
+	locales := make([]Locale, 0)
+	alstr = strings.Replace(alstr, " ", "", -1)
+	if alstr == "" {
+		return locales
+	}
+	al := strings.Split(alstr, ",")
+	for _, lstr := range al {
+		locales = append(locales, Locale{
+			Lang:    parseLang(lstr),
+			Country: parseCountry(lstr),
+			Qual:    parseQual(lstr),
+		})
+	}
+	return locales
+}
+
+// GetLocales returns supported locales for the given requet
+func GetLocales(r *http.Request) []Locale {
+	return supportedLocales(r.Header.Get(acceptLanguage))
+}
+
+// GetPreferredLocale return preferred locale for the given reuqest
+// returns error if there is no preferred locale
+func GetPreferredLocale(r *http.Request) (*Locale, error) {
+	locales := GetLocales(r)
+	if len(locales) == 0 {
+		return &Locale{}, errors.New("No locale found")
+	}
+	return &locales[0], nil
+}
+
+func parseLang(val string) string {
+	locale := strings.Split(val, ";")[0]
+	lang := strings.Split(locale, "-")[0]
+	return lang
+}
+
+func parseCountry(val string) string {
+	locale := strings.Split(val, ";")[0]
+	spl := strings.Split(locale, "-")
+	if len(spl) > 1 {
+		return spl[1]
+	}
+	return ""
+}
+
+func parseQual(val string) float64 {
+	spl := strings.Split(val, ";")
+	if len(spl) > 1 {
+		qualSpl := strings.Split(spl[1], "=")
+		if len(qualSpl) > 1 {
+			qual, err := strconv.ParseFloat(qualSpl[1], 64)
+			if err != nil {
+				return 1
+			}
+			return qual
+		}
+	}
+	return 1
+}
+
diff --git a/i18n/locale_test.go b/i18n/locale_test.go
new file mode 100644
index 0000000..6887064
--- /dev/null
+++ b/i18n/locale_test.go
@@ -0,0 +1,39 @@
+package i18n
+
+import (
+	"testing"
+)
+
+func TestLocale(t *testing.T) {
+	l0 := supportedLocales("ja-JP;q")
+	if len(l0) != 1 {
+		t.Errorf("Expected number of locales \"1\", got %d", len(l0))
+		t.Fail()
+	}
+	l1 := supportedLocales("en,de-AT; q=0.8,de;q=0.6,bg; q=0.4,en-US;q=0.2,sr;q=0.2")
+	if len(l1) != 6 {
+		t.Errorf("Expected number of locales \"6\", got %d", len(l1))
+		t.Fail()
+	}
+	l2 := supportedLocales("en")
+	if len(l2) != 1 {
+		t.Errorf("Expected number of locales \"1\", got %d", len(l2))
+		t.Fail()
+	}
+	l3 := supportedLocales("")
+	if len(l3) != 0 {
+		t.Errorf("Expected number of locales \"0\", got %d", len(l3))
+		t.Fail()
+	}
+	l4 := ParseLocale("en_US")
+	if l4.Lang != "en" || l4.Country != "US" {
+		t.Errorf("Expected \"en\" and \"US\", got %s and %s", l4.Lang, l4.Country)
+		t.Fail()
+	}
+	l5 := ParseLocale("en")
+	if l5.Lang != "en" || l5.Country != "" {
+		t.Errorf("Expected \"en\" and \"\", got %s and %s", l5.Lang, l5.Country)
+		t.Fail()
+	}
+
+}
diff --git a/i18n/translations/de_DE.json b/i18n/translations/de_DE.json
new file mode 100644
index 0000000..c12186d
--- /dev/null
+++ b/i18n/translations/de_DE.json
@@ -0,0 +1,32 @@
+{
+  "main.title" : "CutleryPlus",
+  "main.subtitle" : "Messer, die legte in Besteck geschnitten.",
+  "menu" : {
+    "home" : "Home",
+    "products": {
+      "self": "Produkte",
+      "forks" : "Gabeln",
+      "knives" : "Messer",
+      "spoons" : "Löffel"
+    },
+    "gallery" : "Galerie",
+    "about" :  "Über uns",
+    "contact" : "Kontakt"
+  },
+  "home" : {
+    "title": "Willkommen in CutleryPlus!",
+    "text" : {
+      "p1": "Lorem ipsum...",
+      "p2": "Ein weiterer ipsum lorem."
+    }
+  },
+  "error" : {
+    "404" : "Seite {0} wurde nicht gefunden.",
+    "500" : "Stimmt etwas nicht auf unserer Seite ist, versuchen Sie es erneut.",
+    "contact" : {
+      "name" : "Sie müssen Ihren Namen eingeben.",
+      "email" : "Sie müssen Ihre E-Mail ein.",
+      "text" : "Sie können eine leere Nachricht nicht zu senden."
+    }
+  }
+}
\ No newline at end of file
diff --git a/i18n/translations/en_US.json b/i18n/translations/en_US.json
new file mode 100644
index 0000000..6fa0b8f
--- /dev/null
+++ b/i18n/translations/en_US.json
@@ -0,0 +1,32 @@
+{
+  "main.title" : "CutleryPlus",
+  "main.subtitle" : "Knives that put cut in cutlery.",
+  "menu" : {
+    "home" : "Home",
+    "products": {
+      "self": "Products",
+      "forks" : "Forks",
+      "knives" : "Knives",
+      "spoons" : "Spoons"
+    },
+    "gallery" : "Gallery",
+    "about" : "About us",
+    "contact" : "Contact"
+  },
+  "home" : {
+    "title": "Welcome to CutleryPlus!",
+    "text" : {
+      "p1": "Lorem ipsum...",
+      "p2": "Another ipsum lorem."
+    }
+  },
+  "error" : {
+    "404" : "Page {0} not found!",
+    "500" : "Something is wrong on our side, please try again.",
+    "contact" : {
+      "name" : "You must enter your name.",
+      "email" : "You must enter your email.",
+      "text" : "You cannot send an empty message."
+    }
+  }
+}
\ No newline at end of file
diff --git a/i18n/translations/sr_RS.json b/i18n/translations/sr_RS.json
new file mode 100644
index 0000000..fe2bea5
--- /dev/null
+++ b/i18n/translations/sr_RS.json
@@ -0,0 +1,32 @@
+{
+  "main.title" : "CutleryPlus",
+  "main.subtitle" : "Escajg za svakoga",
+  "menu" : {
+    "home" : "Pocetna",
+    "products": {
+      "self": "Proizvodi",
+      "forks" : "Viljuske",
+      "knives" : "Nozevi",
+      "spoons" : "Kasike"
+    },
+    "gallery" : "Galerija",
+    "about" : "O nama",
+    "contact" : "Kontakt"
+  },
+  "home" : {
+    "title": "Dobrodosli u CutleryPlus!",
+    "text" : {
+      "p1": "Lorem ipsum...",
+      "p2": "Jos jedan ipsum lorem."
+    }
+  },
+  "error" : {
+    "404" : "Stranica {0} ne postoji.",
+    "500" : "Greska sa nase strane, pokusajte ponovo.",
+    "contact" : {
+      "name" : "Ime ne sme biti prazno.",
+      "email" : "Email ne sme biti prazan.",
+      "text" : "Ne mozete poslati praznu poruku."
+    }
+  }
+}
\ No newline at end of file