Add Context (msgctxt) support

README.md

@@ -12,11 +12,12 @@ Version: [0.9.1](https://github.com/leonelquinteros/gotext/releases/tag/v0.9.1)
 - Implements GNU gettext support in native Go.
 - Safe for concurrent use across multiple goroutines. 
 - It works with UTF-8 encoding as it's the default for Go language.
-- Unit tests available 
+- Unit tests available.
 - Language codes are automatically simplified from the form "en_UK" to "en" if the first isn't available.
 - Ready to use inside Go templates.
-- Support for pluralization rules.
-- Support for variables inside translation strings using Go's [fmt package syntax](https://golang.org/pkg/fmt/)
+- Support for [pluralization rules](https://www.gnu.org/software/gettext/manual/html_node/Plural-forms.html).
+- Support for [message context](https://www.gnu.org/software/gettext/manual/html_node/Contexts.html).
+- Support for variables inside translation strings using Go's [fmt package syntax](https://golang.org/pkg/fmt/).
 
 
 

gotext.go

@@ -124,3 +124,32 @@ func GetND(dom, str, plural string, n int, vars ...interface{}) string {
 	// Return translation
 	return storage.GetND(dom, str, plural, n, vars...)
 }
+
+// GetC uses the default domain globally set to return the corresponding translation of the given string in the given context.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func GetC(str, ctx string, vars ...interface{}) string {
+	return GetDC(domain, str, ctx, vars...)
+}
+
+// GetNC retrieves the (N)th plural form translation for the given string in the given context in the "default" domain.
+// If n == 0, usually the singular form of the string is returned as defined in the PO file.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
+	return GetNDC("default", str, plural, n, ctx, vars...)
+}
+
+// GetDC returns the corresponding translation in the given domain for the given string in the given context.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func GetDC(dom, str, ctx string, vars ...interface{}) string {
+	return GetNDC(dom, str, str, 0, ctx, vars...)
+}
+
+// GetNDC retrieves the (N)th plural form translation in the given domain for a given string.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func GetNDC(dom, str, plural string, n int, ctx string, vars ...interface{}) string {
+	// Try to load default package Locale storage
+	loadStorage(false)
+
+	// Return translation
+	return storage.GetNDC(dom, str, plural, n, ctx, vars...)
+}

gotext_test.go

@@ -45,20 +45,41 @@ msgstr[0] "This one is the singular: %s"
 msgstr[1] "This one is the plural: %s"
 msgstr[2] "And this is the second plural form: %s"
 
+msgid "This one has invalid syntax translations"
+msgid_plural "Plural index"
+msgstr[abc] "Wrong index"
+msgstr[1 "Forgot to close brackets"
+msgstr[0] "Badly formatted string'
+
+msgid "Invalid formatted id[] with no translations
+
+msgctxt "Ctx"
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular in a Ctx context: %s"
+msgstr[1] "This one is the plural in a Ctx context: %s"
+
+msgid "Some random"
+msgstr "Some random translation"
+
+msgctxt "Ctx"
+msgid "Some random in a context"
+msgstr "Some random translation in a context"
+
+msgid "More"
+msgstr "More translation"
+
     `
 
-	// Set default configuration
-	Configure("/tmp", "en_US", "default")
-
 	// Create Locales directory on default location
-	dirname := path.Clean(library + string(os.PathSeparator) + "en_US")
+	dirname := path.Clean("/tmp" + string(os.PathSeparator) + "en_US")
 	err := os.MkdirAll(dirname, os.ModePerm)
 	if err != nil {
 		t.Fatalf("Can't create test directory: %s", err.Error())
 	}
 
 	// Write PO content to default domain file
-	filename := path.Clean(dirname + string(os.PathSeparator) + domain + ".po")
+	filename := path.Clean(dirname + string(os.PathSeparator) + "default.po")
 
 	f, err := os.Create(filename)
 	if err != nil {
@@ -71,6 +92,9 @@ msgstr[2] "And this is the second plural form: %s"
 		t.Fatalf("Can't write to test file: %s", err.Error())
 	}
 
+	// Set package configuration
+	Configure("/tmp", "en_US", "default")
+
 	// Test translations
 	tr := Get("My text")
 	if tr != "Translated text" {
@@ -88,6 +112,23 @@ msgstr[2] "And this is the second plural form: %s"
 	if tr != "And this is the second plural form: Variable" {
 		t.Errorf("Expected 'And this is the second plural form: Variable' but got '%s'", tr)
 	}
+
+	// Test context translations
+	tr = GetC("Some random in a context", "Ctx")
+	if tr != "Some random translation in a context" {
+		t.Errorf("Expected 'Some random translation in a context' but got '%s'", tr)
+	}
+
+	v = "Variable"
+	tr = GetC("One with var: %s", "Ctx", v)
+	if tr != "This one is the singular in a Ctx context: Variable" {
+		t.Errorf("Expected 'This one is the singular in a Ctx context: Variable' but got '%s'", tr)
+	}
+
+	tr = GetNC("One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	if tr != "This one is the plural in a Ctx context: Variable" {
+		t.Errorf("Expected 'This one is the plural in a Ctx context: Variable' but got '%s'", tr)
+	}
 }
 
 func TestPackageRace(t *testing.T) {

locale.go

@@ -99,13 +99,13 @@ func (l *Locale) GetN(str, plural string, n int, vars ...interface{}) string {
 	return l.GetND("default", str, plural, n, vars...)
 }
 
-// GetD returns the corresponding translation in the given domain for a given string.
+// GetD returns the corresponding translation in the given domain for the given string.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetD(dom, str string, vars ...interface{}) string {
 	return l.GetND(dom, str, str, 0, vars...)
 }
 
-// GetND retrieves the (N)th plural form translation in the given domain for a given string.
+// GetND retrieves the (N)th plural form translation in the given domain for the given string.
 // If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetND(dom, str, plural string, n int, vars ...interface{}) string {
@@ -124,3 +124,42 @@ func (l *Locale) GetND(dom, str, plural string, n int, vars ...interface{}) stri
 	// Return the same we received by default
 	return fmt.Sprintf(plural, vars...)
 }
+
+// GetC uses a domain "default" to return the corresponding translation of the given string in the given context.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (l *Locale) GetC(str, ctx string, vars ...interface{}) string {
+	return l.GetDC("default", str, ctx, vars...)
+}
+
+// GetNC retrieves the (N)th plural form translation for the given string in the given context in the "default" domain.
+// If n == 0, usually the singular form of the string is returned as defined in the PO file.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (l *Locale) GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
+	return l.GetNDC("default", str, plural, n, ctx, vars...)
+}
+
+// GetDC returns the corresponding translation in the given domain for the given string in the given context.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (l *Locale) GetDC(dom, str, ctx string, vars ...interface{}) string {
+	return l.GetNDC(dom, str, str, 0, ctx, vars...)
+}
+
+// GetNDC retrieves the (N)th plural form translation in the given domain for the given string in the given context.
+// If n == 0, usually the singular form of the string is returned as defined in the PO file.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (l *Locale) GetNDC(dom, str, plural string, n int, ctx string, vars ...interface{}) string {
+	// Sync read
+	l.RLock()
+	defer l.RUnlock()
+
+	if l.domains != nil {
+		if _, ok := l.domains[dom]; ok {
+			if l.domains[dom] != nil {
+				return l.domains[dom].GetNC(str, plural, n, ctx, vars...)
+			}
+		}
+	}
+
+	// Return the same we received by default
+	return fmt.Sprintf(plural, vars...)
+}

locale_test.go

@@ -22,6 +22,30 @@ msgstr[0] "This one is the singular: %s"
 msgstr[1] "This one is the plural: %s"
 msgstr[2] "And this is the second plural form: %s"
 
+msgid "This one has invalid syntax translations"
+msgid_plural "Plural index"
+msgstr[abc] "Wrong index"
+msgstr[1 "Forgot to close brackets"
+msgstr[0] "Badly formatted string'
+
+msgid "Invalid formatted id[] with no translations
+
+msgctxt "Ctx"
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular in a Ctx context: %s"
+msgstr[1] "This one is the plural in a Ctx context: %s"
+
+msgid "Some random"
+msgstr "Some random translation"
+
+msgctxt "Ctx"
+msgid "Some random in a context"
+msgstr "Some random translation in a context"
+
+msgid "More"
+msgstr "More translation"
+
     `
 
 	// Create Locales directory with simplified language code
@@ -82,6 +106,47 @@ msgstr[2] "And this is the second plural form: %s"
 	if tr != "Several with vars: Variable" {
 		t.Errorf("Expected 'Several with vars: Variable' but got '%s'", tr)
 	}
+
+	// Test inexistent translations
+	tr = l.Get("This is a test")
+	if tr != "This is a test" {
+		t.Errorf("Expected 'This is a test' but got '%s'", tr)
+	}
+
+	tr = l.GetN("This is a test", "This are tests", 1)
+	if tr != "This are tests" {
+		t.Errorf("Expected 'This are tests' but got '%s'", tr)
+	}
+
+	// Test syntax error parsed translations
+	tr = l.Get("This one has invalid syntax translations")
+	if tr != "This one has invalid syntax translations" {
+		t.Errorf("Expected 'This one has invalid syntax translations' but got '%s'", tr)
+	}
+
+	tr = l.GetN("This one has invalid syntax translations", "This are tests", 1)
+	if tr != "This are tests" {
+		t.Errorf("Expected 'Plural index' but got '%s'", tr)
+	}
+
+	// Test context translations
+	v = "Test"
+	tr = l.GetDC("my_domain", "One with var: %s", "Ctx", v)
+	if tr != "This one is the singular in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the singular in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test plural
+	tr = l.GetNDC("my_domain", "One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	if tr != "This one is the plural in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the plural in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test last translation
+	tr = l.GetD("my_domain", "More")
+	if tr != "More translation" {
+		t.Errorf("Expected 'More translation' but got '%s'", tr)
+	}
 }
 
 func TestLocaleRace(t *testing.T) {

po.go

@@ -66,6 +66,7 @@ Example:
 type Po struct {
 	// Storage
 	translations map[string]*translation
+	contexts     map[string]map[string]*translation
 
 	// Sync Mutex
 	sync.RWMutex
@@ -95,16 +96,23 @@ func (po *Po) ParseFile(f string) {
 
 // Parse loads the translations specified in the provided string (str)
 func (po *Po) Parse(str string) {
+	// Init storage
 	if po.translations == nil {
 		po.Lock()
 		po.translations = make(map[string]*translation)
+		po.contexts = make(map[string]map[string]*translation)
 		po.Unlock()
 	}
 
+	// Get lines
 	lines := strings.Split(str, "\n")
 
+	// Translation buffer
 	tr := newTranslation()
 
+	// Context buffer
+	ctx := ""
+
 	for _, l := range lines {
 		// Trim spaces
 		l = strings.TrimSpace(l)
@@ -115,19 +123,59 @@ func (po *Po) Parse(str string) {
 		}
 
 		// Skip invalid lines
-		if !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
+		if !strings.HasPrefix(l, "msgctxt") && !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
+			continue
+		}
+
+		// Buffer context and continue
+		if strings.HasPrefix(l, "msgctxt") {
+			// Save current translation buffer.
+			po.Lock()
+			// No context
+			if ctx == "" {
+				po.translations[tr.id] = tr
+			} else {
+				// Save context
+				if _, ok := po.contexts[ctx]; !ok {
+					po.contexts[ctx] = make(map[string]*translation)
+				}
+				po.contexts[ctx][tr.id] = tr
+			}
+			po.Unlock()
+
+			// Flush buffer
+			tr = newTranslation()
+			ctx = ""
+
+			// Buffer context
+			ctx, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgctxt")))
+
+			// Loop
 			continue
 		}
 
 		// Buffer msgid and continue
 		if strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") {
-			// Save current translation buffer.
-			po.Lock()
-			po.translations[tr.id] = tr
-			po.Unlock()
+			// Save current translation buffer if not inside a context.
+			if ctx == "" {
+				po.Lock()
+				po.translations[tr.id] = tr
+				po.Unlock()
 
-			// Flush buffer
-			tr = newTranslation()
+				// Flush buffer
+				tr = newTranslation()
+				ctx = ""
+			} else if ctx != "" && tr.id != "" {
+				// Save current translation buffer inside a context
+				if _, ok := po.contexts[ctx]; !ok {
+					po.contexts[ctx] = make(map[string]*translation)
+				}
+				po.contexts[ctx][tr.id] = tr
+
+				// Flush buffer
+				tr = newTranslation()
+				ctx = ""
+			}
 
 			// Set id
 			tr.id, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgid")))
@@ -178,7 +226,15 @@ func (po *Po) Parse(str string) {
 	// Save last translation buffer.
 	if tr.id != "" {
 		po.Lock()
-		po.translations[tr.id] = tr
+		if ctx == "" {
+			po.translations[tr.id] = tr
+		} else {
+			// Save context
+			if _, ok := po.contexts[ctx]; !ok {
+				po.contexts[ctx] = make(map[string]*translation)
+			}
+			po.contexts[ctx][tr.id] = tr
+		}
 		po.Unlock()
 	}
 }
@@ -217,3 +273,46 @@ func (po *Po) GetN(str, plural string, n int, vars ...interface{}) string {
 	// Return the plural string we received by default
 	return fmt.Sprintf(plural, vars...)
 }
+
+// GetC retrieves the corresponding translation for a given string in the given context.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (po *Po) GetC(str, ctx string, vars ...interface{}) string {
+	// Sync read
+	po.RLock()
+	defer po.RUnlock()
+
+	if po.contexts != nil {
+		if _, ok := po.contexts[ctx]; ok {
+			if po.contexts[ctx] != nil {
+				if _, ok := po.contexts[ctx][str]; ok {
+					return fmt.Sprintf(po.contexts[ctx][str].get(), vars...)
+				}
+			}
+		}
+	}
+
+	// Return the string we received by default
+	return fmt.Sprintf(str, vars...)
+}
+
+// GetNC retrieves the (N)th plural form translation for the given string in the given context.
+// If n == 0, usually the singular form of the string is returned as defined in the PO file.
+// Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
+func (po *Po) GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
+	// Sync read
+	po.RLock()
+	defer po.RUnlock()
+
+	if po.contexts != nil {
+		if _, ok := po.contexts[ctx]; ok {
+			if po.contexts[ctx] != nil {
+				if _, ok := po.contexts[ctx][str]; ok {
+					return fmt.Sprintf(po.contexts[ctx][str].getN(n), vars...)
+				}
+			}
+		}
+	}
+
+	// Return the plural string we received by default
+	return fmt.Sprintf(plural, vars...)
+}

po_test.go

@@ -28,7 +28,25 @@ msgstr[abc] "Wrong index"
 msgstr[1 "Forgot to close brackets"
 msgstr[0] "Badly formatted string'
 
+msgid "Invalid formatted id[] with no translations
+
+msgctxt "Ctx"
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular in a Ctx context: %s"
+msgstr[1] "This one is the plural in a Ctx context: %s"
+
+msgid "Some random"
+msgstr "Some random translation"
+
+msgctxt "Ctx"
+msgid "Some random in a context"
+msgstr "Some random translation in a context"
+
+msgid "More"
+msgstr "More translation"
     `
+
 	// Write PO content to file
 	filename := path.Clean(os.TempDir() + string(os.PathSeparator) + "default.po")
 
@@ -91,6 +109,26 @@ msgstr[0] "Badly formatted string'
 	if tr != "Plural index" {
 		t.Errorf("Expected 'Plural index' but got '%s'", tr)
 	}
+
+	// Test context translations
+	v = "Test"
+	tr = po.GetC("One with var: %s", "Ctx", v)
+	if tr != "This one is the singular in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the singular in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test plural
+	tr = po.GetNC("One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	if tr != "This one is the plural in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the plural in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test last translation
+	tr = po.Get("More")
+	if tr != "More translation" {
+		t.Errorf("Expected 'More translation' but got '%s'", tr)
+	}
+
 }
 
 func TestTranslationObject(t *testing.T) {