✨ add i18n support

common/i18n/bundle.go

@@ -0,0 +1,16 @@
+package i18n
+
+import (
+	i18n2 "github.com/nicksnyder/go-i18n/v2/i18n"
+	"github.com/pelletier/go-toml/v2"
+	"golang.org/x/text/language"
+)
+
+func NewBundle(tag language.Tag, configs ...string) *i18n2.Bundle {
+	bundle := i18n2.NewBundle(tag)
+	bundle.RegisterUnmarshalFunc("toml", toml.Unmarshal)
+	for _, file := range configs {
+		bundle.LoadMessageFile(file)
+	}
+	return bundle
+}

common/i18n/cache.go

@@ -0,0 +1,62 @@
+package i18n
+
+import (
+	"context"
+	"net/http"
+
+	i18n2 "github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
+	"google.golang.org/grpc/metadata"
+)
+
+/*
+type Cache interface {
+	GetLocalizer() (*i18n2.Localizer, bool)
+	SetLocalizer(l *i18n2.Localizer)
+}
+*/
+
+func getLocalizer(ctx context.Context) (*i18n2.Localizer, bool) {
+	v := ctx.Value(I18nKey)
+	if l, b := v.(*i18n2.Localizer); b {
+		return l, true
+	}
+	return nil, false
+}
+
+func withRequest(r *http.Request, currentLang language.Tag, bundle *i18n2.Bundle) *http.Request {
+
+	accept := r.Header.Get(defaultLangHeaderKey)
+	localizer := i18n2.NewLocalizer(bundle, accept)
+	ctx := setLocalizer(r.Context(), localizer)
+	ctx = setCurrentLang(ctx, currentLang)
+	ctx = metadata.AppendToOutgoingContext(ctx, defaultLangHeaderKey, accept)
+	return r.WithContext(ctx)
+}
+
+func setCurrentLang(ctx context.Context, currentLang language.Tag) context.Context {
+	return context.WithValue(ctx, I18nCurrentLangKey, currentLang)
+}
+
+func setLocalizer(ctx context.Context, l *i18n2.Localizer) context.Context {
+	return context.WithValue(ctx, I18nKey, l)
+}
+
+func IsHasI18n(ctx context.Context) bool {
+	v := ctx.Value(I18nKey)
+	if v != nil {
+		return true
+	}
+	return false
+}
+
+// func isHasI18n(ctx context.Context) bool {
+//	if use, exist := ctx.Value(isUseI18n).(bool); exist {
+//		return use
+//	}
+//	return false
+// }
+//
+// func setHasI18n(ctx context.Context, use bool) context.Context {
+//	return context.WithValue(ctx, isUseI18n, use)
+// }

common/i18n/i18n.go

@@ -0,0 +1,61 @@
+package i18n
+
+import (
+	"context"
+
+	i18n2 "github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
+)
+
+func FormatText(ctx context.Context, msgId string, defaultText string) string {
+	return FormatTextWithData(ctx, msgId, defaultText, nil)
+}
+
+func FormatTextWithData(ctx context.Context, msgId string, defaultText string, args map[string]interface{}) string {
+	return FormatMessage(ctx, &i18n2.Message{
+		ID:    msgId,
+		Other: defaultText,
+	}, args)
+}
+
+func FormatMessage(ctx context.Context, message *i18n2.Message, args map[string]interface{}) string {
+	if localizer, ok := getLocalizer(ctx); ok {
+		return localizer.MustLocalize(&i18n2.LocalizeConfig{
+			DefaultMessage: message,
+			TemplateData:   args,
+		})
+	}
+	return formatInternalMessage(message, args)
+}
+
+func formatInternalMessage(message *i18n2.Message, args map[string]interface{}) string {
+	if args == nil {
+		return message.Other
+	}
+	tpl := i18n2.NewMessageTemplate(message)
+	msg, err := tpl.Execute("other", args, nil)
+	if err != nil {
+		panic(err)
+	}
+	return msg
+}
+
+func FetchCurrentLanguageFromCtx(ctx context.Context) (*language.Tag, bool) {
+	v := ctx.Value(I18nCurrentLangKey)
+	if l, b := v.(language.Tag); b {
+		return &l, true
+	}
+	return nil, false
+}
+
+func LocalizedString(ctx context.Context, defaultValue string, langMap map[language.Tag]string) string {
+	langTag, tagExists := FetchCurrentLanguageFromCtx(ctx)
+	if !tagExists {
+		return defaultValue
+	}
+	str, ok := langMap[*langTag]
+	if !ok {
+		return defaultValue
+	}
+	return str
+}

common/i18n/keys.go

@@ -0,0 +1,21 @@
+package i18n
+
+const I18nKey = "i18n"
+const I18nCurrentLangKey = "lang"
+
+var (
+	defaultLangHeaderKey        = "Accept-Language"
+	defaultErrCode       uint32 = 10001
+)
+
+// SetDefaultLangHeaderKey sets the default value of the lang header key.
+// need to be set before use
+func SetDefaultLangHeaderKey(key string) {
+	defaultLangHeaderKey = key
+}
+
+// SetDefaultErrCode sets the default value of the err code.
+// need to be set before use
+func SetDefaultErrCode(code uint32) {
+	defaultErrCode = code
+}

common/i18n/middleware.go

@@ -0,0 +1,28 @@
+package i18n
+
+import (
+	"net/http"
+
+	"golang.org/x/text/language"
+)
+
+type I18nMiddleware struct {
+	supportTags       []language.Tag
+	localizationFiles []string
+}
+
+func NewI18nMiddleware(supportTags []language.Tag, localizationFiles []string) *I18nMiddleware {
+	return &I18nMiddleware{
+		supportTags:       supportTags,
+		localizationFiles: localizationFiles,
+	}
+}
+
+func (m *I18nMiddleware) Handle(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		lang := r.Header.Get(defaultLangHeaderKey)
+		langTag := MatchCurrentLanguageTag(lang, m.supportTags)
+		bundle := NewBundle(langTag, m.localizationFiles...)
+		next(w, withRequest(r, langTag, bundle))
+	}
+}

common/i18n/parse.go

@@ -0,0 +1,14 @@
+package i18n
+
+import "golang.org/x/text/language"
+
+func MatchCurrentLanguageTag(accept string, supportTags []language.Tag) language.Tag {
+	langTags, _, err := language.ParseAcceptLanguage(accept)
+	if err != nil {
+		langTags = []language.Tag{language.English}
+	}
+	var matcher = language.NewMatcher(supportTags)
+	_, i, _ := matcher.Match(langTags...)
+	tag := supportTags[i]
+	return tag
+}

common/i18n/rpc_interceptor.go

@@ -0,0 +1,74 @@
+package i18n
+
+import (
+	"context"
+	"log"
+
+	i18n2 "github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+var rpcInterceptorDebug = false
+
+func WithRpcInterceptorDebug(debug bool) {
+	rpcInterceptorDebug = debug
+}
+
+type I18nGrpcInterceptor struct {
+	supportTags       []language.Tag
+	localizationFiles []string
+}
+
+func NewI18nGrpcInterceptor(supportTags []language.Tag, localizationFiles []string) *I18nGrpcInterceptor {
+	if len(supportTags) == 0 {
+		panic("supportTags can not be empty")
+	}
+	return &I18nGrpcInterceptor{
+		supportTags:       supportTags,
+		localizationFiles: localizationFiles,
+	}
+}
+
+func (i *I18nGrpcInterceptor) Interceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+	ctx, err = i.saveLocalize(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return handler(ctx, req)
+}
+
+func (i *I18nGrpcInterceptor) saveLocalize(ctx context.Context) (context.Context, error) {
+	respHeader, ok := metadata.FromIncomingContext(ctx)
+	// lang := "en-US" //language.English
+	langTag := i.supportTags[0]
+	lang := langTag.String()
+	if ok {
+		langs := respHeader.Get(defaultLangHeaderKey)
+		if len(langs) == 0 {
+			// return nil, status.Error(codes.Code(defaultErrCode), "can not correct get language")
+			if rpcInterceptorDebug {
+				log.Printf("can not correct get language")
+			}
+		} else {
+			lang = langs[0]
+			langTag = MatchCurrentLanguageTag(lang, i.supportTags)
+		}
+	} else {
+		if rpcInterceptorDebug {
+			log.Printf("can not correct get metadata1")
+		}
+		// return nil, status.Error(codes.Code(defaultErrCode), "can not correct get metadata1")
+	}
+
+	// lang := langs[0]
+	// langTag := MatchCurrentLanguageTag(lang, i.supportTags)
+	bundle := NewBundle(langTag, i.localizationFiles...)
+	localizer := i18n2.NewLocalizer(bundle, lang)
+	ctx = setLocalizer(ctx, localizer)
+
+	// Append the language metadata to the outgoing context
+	ctx = metadata.AppendToOutgoingContext(ctx, defaultLangHeaderKey, lang)
+	return ctx, nil
+}