add support for the go standard embed tag for locale files

_examples/i18n/template-embedded/locales/el-GR/other.ini

@@ -0,0 +1,10 @@
+[nav]
+User = Λογαριασμός
+
+[debug]
+Title = Μενού προγραμματιστή
+AccessLog = Πρόσβαση στο αρχείο καταγραφής
+AccessLogClear = Καθαρισμός {{tr "debug.AccessLog"}}
+
+[user.connections]
+Title = {{tr "nav.User"}} Συνδέσεις

_examples/i18n/template-embedded/locales/el-GR/user.ini

@@ -0,0 +1,4 @@
+[forms]
+member = μέλος
+register = Γίνε {{uppercase (tr "forms.member") }}
+registered = εγγεγραμμένοι

_examples/i18n/template-embedded/locales/en-US/other.ini

@@ -0,0 +1,12 @@
+# just an example of some more nested keys,
+# see /other endpoint.
+[nav]
+User = Account
+
+[debug]
+Title = Developer Menu
+AccessLog = Access Log
+AccessLogClear = Clear {{tr "debug.AccessLog"}}
+
+[user.connections]
+Title = {{tr "nav.User"}} Connections

_examples/i18n/template-embedded/locales/en-US/user.ini

@@ -0,0 +1,4 @@
+[forms]
+member = member
+register = Become a {{uppercase (tr "forms.member") }}
+registered = registered

_examples/i18n/template-embedded/main.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"embed"
+	"strings"
+	"text/template"
+
+	"github.com/kataras/iris/v12"
+)
+
+//go:embed locales/*
+var filesystem embed.FS
+
+func main() {
+	app := newApp()
+	app.Listen(":8080")
+}
+
+func newApp() *iris.Application {
+	app := iris.New()
+
+	// Set custom functions per locale!
+	app.I18n.Loader.Funcs = func(current iris.Locale) template.FuncMap {
+		return template.FuncMap{
+			"uppercase": func(word string) string {
+				return strings.ToUpper(word)
+			},
+		}
+	}
+
+	// Instead of:
+	// err := app.I18n.Load("./locales/*/*.ini", "en-US", "el-GR")
+	// Apply the below in order to build with embedded locales inside your executable binary.
+	err := app.I18n.LoadFS(filesystem, ".", "en-US", "el-GR")
+	if err != nil {
+		panic(err)
+	}
+
+	app.Get("/", func(ctx iris.Context) {
+		text := ctx.Tr("forms.register") // en-US: prints "Become a MEMBER".
+		ctx.WriteString(text)
+	})
+
+	app.Get("/title", func(ctx iris.Context) {
+		text := ctx.Tr("user.connections.Title") // en-US: prints "Accounts Connections".
+		ctx.WriteString(text)
+	})
+
+	return app
+}

_examples/i18n/template-embedded/main_test.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/kataras/iris/v12/httptest"
+)
+
+func TestI18nLoaderFuncMap(t *testing.T) {
+	app := newApp()
+
+	e := httptest.New(t, app)
+	e.GET("/").Expect().Status(httptest.StatusOK).
+		Body().Equal("Become a MEMBER")
+	e.GET("/title").Expect().Status(httptest.StatusOK).
+		Body().Equal("Account Connections")
+	e.GET("/").WithHeader("Accept-Language", "el").Expect().Status(httptest.StatusOK).
+		Body().Equal("Γίνε ΜΈΛΟΣ")
+	e.GET("/title").WithHeader("Accept-Language", "el").Expect().Status(httptest.StatusOK).
+		Body().Equal("Λογαριασμός Συνδέσεις")
+}