Add lang.HasTranslation

Fixes #10538

Author: bep

deps/deps.go

@@ -1,3 +1,16 @@
+// Copyright 2022 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package deps
 
 import (
@@ -69,8 +82,8 @@ type Deps struct {
 	// The file cache to use.
 	FileCaches filecache.Caches
 
-	// The translation func to use
-	Translate func(translationID string, templateData any) string `json:"-"`
+	// The translator interface  to use
+	Translator langs.Translator `json:"-"`
 
 	// The language in use. TODO(bep) consolidate with site
 	Language *langs.Language

langs/i18n/i18n.go

@@ -1,4 +1,4 @@
-// Copyright 2017 The Hugo Authors. All rights reserved.
+// Copyright 2022 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -24,54 +24,76 @@ import (
 	"github.com/gohugoio/hugo/common/loggers"
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/langs"
 
 	"github.com/gohugoio/go-i18n/v2/i18n"
 )
 
+type translator struct {
+	translate      func(translationID string, templateData any) string
+	hasTranslation func(translationID string) bool
+}
+
+var nopTranslator = translator{}
+
+func (t translator) Translate(translationID string, templateData any) string {
+	if t.translate == nil {
+		return ""
+	}
+	return t.translate(translationID, templateData)
+}
+
+func (t translator) HasTranslation(translationID string) bool {
+	if t.hasTranslation == nil {
+		return false
+	}
+	return t.hasTranslation(translationID)
+}
+
 type translateFunc func(translationID string, templateData any) string
 
 var i18nWarningLogger = helpers.NewDistinctErrorLogger()
 
-// Translator handles i18n translations.
-type Translator struct {
-	translateFuncs map[string]translateFunc
-	cfg            config.Provider
-	logger         loggers.Logger
+// Translators handles i18n translations.
+type Translators struct {
+	translators map[string]langs.Translator
+	cfg         config.Provider
+	logger      loggers.Logger
 }
 
 // NewTranslator creates a new Translator for the given language bundle and configuration.
-func NewTranslator(b *i18n.Bundle, cfg config.Provider, logger loggers.Logger) Translator {
-	t := Translator{cfg: cfg, logger: logger, translateFuncs: make(map[string]translateFunc)}
+func NewTranslator(b *i18n.Bundle, cfg config.Provider, logger loggers.Logger) Translators {
+	t := Translators{cfg: cfg, logger: logger, translators: make(map[string]langs.Translator)}
 	t.initFuncs(b)
 	return t
 }
 
-// Func gets the translate func for the given language, or for the default
+// Get gets the Translator for the given language, or for the default
 // configured language if not found.
-func (t Translator) Func(lang string) translateFunc {
-	if f, ok := t.translateFuncs[lang]; ok {
-		return f
+func (ts Translators) Get(lang string) langs.Translator {
+	if t, ok := ts.translators[lang]; ok {
+		return t
 	}
-	t.logger.Infof("Translation func for language %v not found, use default.", lang)
-	if f, ok := t.translateFuncs[t.cfg.GetString("defaultContentLanguage")]; ok {
-		return f
+	ts.logger.Infof("Translation func for language %v not found, use default.", lang)
+	if tt, ok := ts.translators[ts.cfg.GetString("defaultContentLanguage")]; ok {
+		return tt
 	}
 
-	t.logger.Infoln("i18n not initialized; if you need string translations, check that you have a bundle in /i18n that matches the site language or the default language.")
-	return func(translationID string, args any) string {
-		return ""
-	}
+	ts.logger.Infoln("i18n not initialized; if you need string translations, check that you have a bundle in /i18n that matches the site language or the default language.")
+
+	return nopTranslator
 }
 
-func (t Translator) initFuncs(bndl *i18n.Bundle) {
-	enableMissingTranslationPlaceholders := t.cfg.GetBool("enableMissingTranslationPlaceholders")
+func (ts Translators) initFuncs(bndl *i18n.Bundle) {
+	enableMissingTranslationPlaceholders := ts.cfg.GetBool("enableMissingTranslationPlaceholders")
 	for _, lang := range bndl.LanguageTags() {
 		currentLang := lang
 		currentLangStr := currentLang.String()
 		// This may be pt-BR; make it case insensitive.
 		currentLangKey := strings.ToLower(strings.TrimPrefix(currentLangStr, artificialLangTagPrefix))
 		localizer := i18n.NewLocalizer(bndl, currentLangStr)
-		t.translateFuncs[currentLangKey] = func(translationID string, templateData any) string {
+
+		translate := func(translationID string, templateData any) (string, error) {
 			pluralCount := getPluralCount(templateData)
 
 			if templateData != nil {
@@ -90,10 +112,12 @@ func (t Translator) initFuncs(bndl *i18n.Bundle) {
 				PluralCount:  pluralCount,
 			})
 
+			fmt.Println("translatedLang", translatedLang, "currentLang", currentLang, "err", err, "translated", translated)
+
 			sameLang := currentLang == translatedLang
 
 			if err == nil && sameLang {
-				return translated
+				return translated, nil
 			}
 
 			if err != nil && sameLang && translated != "" {
@@ -102,24 +126,41 @@ func (t Translator) initFuncs(bndl *i18n.Bundle) {
 				// but currently we get an error even if the fallback to
 				// "other" succeeds.
 				if fmt.Sprintf("%T", err) == "i18n.pluralFormNotFoundError" {
-					return translated
+					return translated, nil
 				}
 			}
 
+			return translated, err
+
+		}
+
+		translateAndLogIfNeeded := func(translationID string, templateData any) string {
+			translated, err := translate(translationID, templateData)
+			if err == nil {
+				return translated
+			}
+
 			if _, ok := err.(*i18n.MessageNotFoundErr); !ok {
-				t.logger.Warnf("Failed to get translated string for language %q and ID %q: %s", currentLangStr, translationID, err)
+				ts.logger.Warnf("Failed to get translated string for language %q and ID %q: %s", currentLangStr, translationID, err)
 			}
 
-			if t.cfg.GetBool("logI18nWarnings") {
+			if ts.cfg.GetBool("logI18nWarnings") {
 				i18nWarningLogger.Printf("i18n|MISSING_TRANSLATION|%s|%s", currentLangStr, translationID)
 			}
 
 			if enableMissingTranslationPlaceholders {
 				return "[i18n] " + translationID
 			}
-
 			return translated
 		}
+
+		ts.translators[currentLangKey] = translator{
+			translate: translateAndLogIfNeeded,
+			hasTranslation: func(translationID string) bool {
+				_, err := translate(translationID, nil)
+				return err == nil
+			},
+		}
 	}
 }
 

langs/i18n/i18n_test.go

@@ -1,4 +1,4 @@
-// Copyright 2017 The Hugo Authors. All rights reserved.
+// Copyright 2022 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -407,10 +407,10 @@ other = "{{ . }} miesiąca"
 			c.Assert(err, qt.IsNil)
 			c.Assert(d.LoadResources(), qt.IsNil)
 
-			f := tp.t.Func(test.lang)
+			f := tp.t.Get(test.lang)
 
 			for _, variant := range test.variants {
-				c.Assert(f(test.id, variant.Key), qt.Equals, variant.Value, qt.Commentf("input: %v", variant.Key))
+				c.Assert(f.Translate(test.id, variant.Key), qt.Equals, variant.Value, qt.Commentf("input: %v", variant.Key))
 				c.Assert(int(depsCfg.Logger.LogCounters().WarnCounter.Count()), qt.Equals, 0)
 			}
 
@@ -421,8 +421,8 @@ other = "{{ . }} miesiąca"
 
 func doTestI18nTranslate(t testing.TB, test i18nTest, cfg config.Provider) string {
 	tp := prepareTranslationProvider(t, test, cfg)
-	f := tp.t.Func(test.lang)
-	return f(test.id, test.args)
+	f := tp.t.Get(test.lang)
+	return f.Translate(test.id, test.args)
 }
 
 type countField struct {
@@ -541,8 +541,8 @@ func BenchmarkI18nTranslate(b *testing.B) {
 			tp := prepareTranslationProvider(b, test, v)
 			b.ResetTimer()
 			for i := 0; i < b.N; i++ {
-				f := tp.t.Func(test.lang)
-				actual := f(test.id, test.args)
+				f := tp.t.Get(test.lang)
+				actual := f.Translate(test.id, test.args)
 				if actual != test.expected {
 					b.Fatalf("expected %v got %v", test.expected, actual)
 				}

langs/i18n/integration_test.go

@@ -55,3 +55,41 @@ l1: {{ i18n "l1"  }}|l2: {{ i18n "l2"  }}|l3: {{ i18n "l3"  }}
 l1: l1main|l2: l2main|l3: l3theme
 	`)
 }
+
+func TestHasLanguage(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- config.toml --
+baseURL = "https://example.org"
+defaultContentLanguage = "en"
+defaultContentLanguageInSubDir = true
+[languages]
+[languages.en]
+weight=10
+[languages.nn]
+weight=20
+-- i18n/en.toml --
+key1.other = "en key1"
+key2.other = "en key2"
+
+-- i18n/nn.toml --
+key1.other = "nn key1"
+key3.other = "nn key2"
+-- layouts/index.html --
+key1: {{ lang.HasTranslation "key1" }}|
+key2: {{ lang.HasTranslation "key2" }}|
+key3: {{ lang.HasTranslation "key3" }}|
+
+  `
+
+	b := hugolib.NewIntegrationTestBuilder(
+		hugolib.IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+		},
+	).Build()
+
+	b.AssertFileContent("public/en/index.html", "key1: true|\nkey2: true|\nkey3: false|")
+	b.AssertFileContent("public/nn/index.html", "key1: true|\nkey2: false|\nkey3: true|")
+}

langs/i18n/translationProvider.go

@@ -1,4 +1,4 @@
-// Copyright 2017 The Hugo Authors. All rights reserved.
+// Copyright 2022 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"github.com/gohugoio/hugo/common/paths"
+	"github.com/gohugoio/hugo/deps"
 
 	"github.com/gohugoio/hugo/common/herrors"
 	"golang.org/x/text/language"
@@ -28,15 +29,14 @@ import (
 	"github.com/gohugoio/hugo/helpers"
 	toml "github.com/pelletier/go-toml/v2"
 
-	"github.com/gohugoio/hugo/deps"
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/gohugoio/hugo/source"
 )
 
 // TranslationProvider provides translation handling, i.e. loading
 // of bundles etc.
 type TranslationProvider struct {
-	t Translator
+	t Translators
 }
 
 // NewTranslationProvider creates a new translation provider.
@@ -73,7 +73,7 @@ func (tp *TranslationProvider) Update(d *deps.Deps) error {
 
 	tp.t = NewTranslator(bundle, d.Cfg, d.Log)
 
-	d.Translate = tp.t.Func(d.Language.Lang)
+	d.Translator = tp.t.Get(d.Language.Lang)
 
 	return nil
 }
@@ -119,7 +119,7 @@ func addTranslationFile(bundle *i18n.Bundle, r source.File) error {
 
 // Clone sets the language func for the new language.
 func (tp *TranslationProvider) Clone(d *deps.Deps) error {
-	d.Translate = tp.t.Func(d.Language.Lang)
+	d.Translator = tp.t.Get(d.Language.Lang)
 
 	return nil
 }

langs/language.go

@@ -329,3 +329,8 @@ type Collator struct {
 func (c *Collator) CompareStrings(a, b string) int {
 	return c.c.CompareString(a, b)
 }
+
+type Translator interface {
+	Translate(translationID string, templateData any) string
+	HasTranslation(translationID string) bool
+}

tpl/lang/lang.go

@@ -60,7 +60,16 @@ func (ns *Namespace) Translate(id any, args ...any) (string, error) {
 		return "", nil
 	}
 
-	return ns.deps.Translate(sid, templateData), nil
+	return ns.deps.Translator.Translate(sid, templateData), nil
+}
+
+// HasTranslation returns true if the translation key is translated in the current language.
+func (ns *Namespace) HasTranslation(key any) bool {
+	keys, err := cast.ToStringE(key)
+	if err != nil {
+		return false
+	}
+	return ns.deps.Translator.HasTranslation(keys)
 }
 
 // FormatNumber formats number with the given precision for the current language.