Added support for messages with variable arguments

- Refactored GetMessage(locale, name) to Message(locale, name, args...)
- Refactored/expanded tests for Message

i18n.go

@@ -32,7 +32,7 @@ func MessageLocales() []string {
 // Perform a message look-up for the given locale and message.
 //
 // When either an unknown locale or message is detected, a specially formatted string is returned.
-func GetMessage(locale string, message string) (value string) {
+func Message(locale, message string, args ...interface{}) (value string) {
 	messageConfig, knownLocale := messages[locale]
 	if !knownLocale {
 		WARN.Printf("Unknown locale '%s' for message '%s'", locale, message)
@@ -45,6 +45,11 @@ func GetMessage(locale string, message string) (value string) {
 		return fmt.Sprintf(unknownValueFormat, message)
 	}
 
+	if len(args) > 0 {
+		TRACE.Printf("Arguments detected, formatting '%s' with %v", value, args)
+		value = fmt.Sprintf(value, args...)
+	}
+
 	return value
 }
 

i18n_test.go

@@ -17,38 +17,49 @@ func TestI8nLoadMessages(t *testing.T) {
 	}
 }
 
-func TestI8nGetMessage(t *testing.T) {
+func TestI8nMessage(t *testing.T) {
 	loadMessages(testDataPath)
 
 	// Assert that we can get a message and we get the expected return value
-	if message := GetMessage("nl", "greeting"); message != "Hallo" {
-		t.Error("Message 'greeting' for locale 'nl' does not have the expected value")
+	if message := Message("nl", "greeting"); message != "Hallo" {
+		t.Errorf("Message 'greeting' for locale 'nl' (%s) does not have the expected value", message)
 	}
-	if message := GetMessage("en", "greeting"); message != "Hello" {
-		t.Error("Message 'greeting' for locale 'en' does not have the expected value")
+	if message := Message("en", "greeting"); message != "Hello" {
+		t.Errorf("Message 'greeting' for locale 'en' (%s) does not have the expected value", message)
 	}
-	if message := GetMessage("en", "folded"); message != "Greeting is 'Hello'" {
+	if message := Message("en", "folded"); message != "Greeting is 'Hello'" {
 		t.Error("Unexpected unfolded message: ", message)
 	}
+	if message := Message("en", "arguments.string", "Vincent Hanna"); message != "My name is Vincent Hanna" {
+		t.Errorf("Message 'arguments.string' for locale 'en' (%s) does not have the expected value", message)
+	}
+	if message := Message("en", "arguments.hex", 1234567, 1234567); message != "The number 1234567 in hexadecimal notation would be 12d687" {
+		t.Errorf("Message 'arguments.hex' for locale 'en' (%s) does not have the expected value", message)
+	}
 
 	// TODO: re-enable this test once files merging has been implemented
-	/*if message := GetMessage("en", "greeting2"); message != "Yo!" {
+	/*if message := Message("en", "greeting2"); message != "Yo!" {
 		t.Error("Message 'greeting2' for locale 'en' does not have the expected value")
 	}*/
 
 	// Assert that we get the expected return value for a locale that doesn't exist
-	if message := GetMessage("unknown locale", "message"); message != "??? unknown locale ???" {
-		t.Error("Locale 'doesn't exist' is not supposed to exist")
+	if message := Message("unknown locale", "message"); message != "??? unknown locale ???" {
+		t.Error("Locale 'unknown locale' is not supposed to exist")
 	}
-
 	// Assert that we get the expected return value for a message that doesn't exist
-	if message := GetMessage("nl", "unknown message"); message != "??? unknown message ???" {
-		t.Error("Message 'doesn't exist' is not supposed to exist")
+	if message := Message("nl", "unknown message"); message != "??? unknown message ???" {
+		t.Error("Message 'unknown message' is not supposed to exist")
+	}
+}
+
+func BenchmarkI8nMessage(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Message("nl", "greeting")
 	}
 }
 
-func BenchmarkI8nGetMessage(b *testing.B) {
+func BenchmarkI8nMessageWithArguments(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		GetMessage("nl", "greeting")
+		Message("en", "greeting")
 	}
 }

testdata/i18n/messages/english_messages.en

@@ -4,6 +4,9 @@ greeting.suffix=, welcome to Revel!
 
 folded=Greeting is '%(greeting)s'
 
+arguments.string=My name is %s
+arguments.hex=The number %d in hexadecimal notation would be %x
+
 [AU]
 greeting=G'day