feat(ui): add support for translated message in MessageText

Signed-off-by: xsahil03x <[email protected]>

packages/stream_chat_flutter/lib/src/message_text.dart

@@ -29,12 +29,19 @@ class MessageText extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    //print(StreamChat.of(context).user);
+    final streamChat = StreamChat.of(context);
-    final text = _replaceMentions(message.text ?? '').replaceAll('\n', '\n\n');
+    assert(streamChat.currentUser != null, '');
-
+    return BetterStreamBuilder(
+      stream: streamChat.currentUserStream.map((it) => it!.language),
+      initialData: streamChat.currentUser!.language,
+      builder: (context, language) {
+        final translatedText =
+            message.i18n?['${language}_text'] ?? message.text;
+        final messageText =
+            _replaceMentions(translatedText ?? '').replaceAll('\n', '\n\n');
         final themeData = Theme.of(context);
         return MarkdownBody(
-      data: text,
+          data: messageText,
           onTapLink: (
             String link,
             String? href,
@@ -76,14 +83,17 @@ class MessageText extends StatelessWidget {
             p: messageTheme.messageText,
           ),
         );
+      },
+    );
   }
 
   String _replaceMentions(String text) {
-    message.mentionedUsers.map((u) => u.name).toSet().forEach((userName) {
+    var messageTextToRender = text;
-      // ignore: parameter_assignments
+    for (final user in message.mentionedUsers.toSet()) {
-      text = text.replaceAll(
+      final userName = user.name;
+      messageTextToRender = messageTextToRender.replaceAll(
           '@$userName', '[@$userName](@${userName.replaceAll(' ', '')})');
-    });
+    }
-    return text;
+    return messageTextToRender;
   }
 }

packages/stream_chat_flutter/test/src/message_text_test.dart

@@ -8,6 +8,28 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart';
 import 'mocks.dart';
 import 'simple_frame.dart';
 
+void expectTextStrings(Iterable<Widget> widgets, List<String> strings) {
+  var currentString = 0;
+  for (final widget in widgets) {
+    if (widget is RichText) {
+      final span = widget.text as TextSpan;
+      final text = _extractTextFromTextSpan(span);
+      expect(text, equals(strings[currentString]));
+      currentString += 1;
+    }
+  }
+}
+
+String _extractTextFromTextSpan(TextSpan span) {
+  var text = span.text ?? '';
+  if (span.children != null) {
+    for (final child in span.children! as Iterable<TextSpan>) {
+      text += _extractTextFromTextSpan(child);
+    }
+  }
+  return text;
+}
+
 void main() {
   testWidgets(
     'it should show correct message text',
@@ -54,6 +76,103 @@ void main() {
     },
   );
 
+  group('Message with i18n field', () {
+    final client = MockClient();
+    final clientState = MockClientState();
+    final channel = MockChannel();
+    final channelState = MockChannelState();
+    const messageTheme = MessageTheme();
+
+    final currentUser = OwnUser(
+      id: 'sahil',
+      language: 'hi',
+    );
+
+    setUp(() {
+      when(() => client.state).thenReturn(clientState);
+      when(() => clientState.currentUser).thenReturn(currentUser);
+      when(() => clientState.currentUserStream)
+          .thenAnswer((_) => Stream.value(currentUser));
+
+      when(() => channel.state).thenReturn(channelState);
+      when(() => channel.client).thenReturn(client);
+      when(() => channel.isMuted).thenReturn(false);
+      when(() => channel.isMutedStream).thenAnswer((_) => Stream.value(false));
+    });
+
+    testWidgets(
+      'should show correct translated message text as per user language',
+      (WidgetTester tester) async {
+        final message = Message(
+          text: 'Hello',
+          i18n: const {
+            'en_text': 'Hello',
+            'hi_text': 'नमस्ते',
+            'language': 'en',
+          },
+        );
+
+        await tester.pumpWidget(
+          MaterialApp(
+            home: StreamChat(
+              client: client,
+              child: StreamChannel(
+                channel: channel,
+                child: Scaffold(
+                  body: MessageText(
+                    message: message,
+                    messageTheme: messageTheme,
+                  ),
+                ),
+              ),
+            ),
+          ),
+        );
+
+        expect(find.byType(MarkdownBody), findsOneWidget);
+
+        final widgets = tester.allWidgets;
+        expectTextStrings(widgets, <String>['नमस्ते']);
+      },
+    );
+
+    testWidgets(
+      '''should show default text if i18n does not contain translations as per user language''',
+      (WidgetTester tester) async {
+        final message = Message(
+          text: 'Hello',
+          i18n: const {
+            'en_text': 'Hello',
+            'fr_text': 'Bonjour',
+            'language': 'en',
+          },
+        );
+
+        await tester.pumpWidget(
+          MaterialApp(
+            home: StreamChat(
+              client: client,
+              child: StreamChannel(
+                channel: channel,
+                child: Scaffold(
+                  body: MessageText(
+                    message: message,
+                    messageTheme: messageTheme,
+                  ),
+                ),
+              ),
+            ),
+          ),
+        );
+
+        expect(find.byType(MarkdownBody), findsOneWidget);
+
+        final widgets = tester.allWidgets;
+        expectTextStrings(widgets, <String>['Hello']);
+      },
+    );
+  });
+
   testGoldens(
     'control test',
     (WidgetTester tester) async {