fix streaming error handling

Author: hahastudio

README.md

@@ -7,9 +7,22 @@ A new Flutter project which communicates with [OpenAI API](https://platform.open
 ![Screenshot 1](/document/readme_screenshot_01.png)
 ![Screenshot 2](/document/readme_screenshot_02.png)
 
-### Architecture
+## Features
 
-It uses [Flutter framework](https://flutter.dev/), and uses [BLoC pattern](https://pub.dev/packages/flutter_bloc) to implement state management.
+- Support [requesting organization](https://platform.openai.com/docs/api-reference/requesting-organization)
+- Support [system message](https://platform.openai.com/docs/guides/chat/introduction)
+- Support [streaming message](https://platform.openai.com/docs/api-reference/chat/create#chat/create-stream) like ChatGPT
+
+## How to use
+
+1. Get [OpenAI API Key](https://platform.openai.com/docs/api-reference/authentication)
+2. Tap setting button on top right corner to set API Key (required) and Organization (optional)
+3. Add a new conversation
+4. Chat with Open AI!
+
+## Architecture
+
+It uses [Flutter framework](https://flutter.dev/), and uses [BLoC pattern](https://bloclibrary.dev/) to implement state management.
 
 ## How to build
 
@@ -32,7 +45,7 @@ Mainly used Flutter packages:
 - [shared_preferences](https://pub.dev/packages/shared_preferences) to store app settings & conversations
 - [flutter_bloc](https://pub.dev/packages/flutter_bloc) for state management
 - [settings_ui](https://pub.dev/packages/settings_ui) for setting page
-- [flutter_spinkit](https://pub.dev/packages/flutter_spinkit) to show a fancy loading indicators
+- [flutter_markdown](https://pub.dev/packages/flutter_markdown) to render messages in markdown format
 
 ## License
 

document/readme_screenshot_02.png

@@ -76,9 +76,9 @@ class OpenAiApi {
         // data: [DONE]
         final String data = utf8.decode(value);
         final List<String> dataLines = data
-            .split('\n')
-            .where((element) => element.isNotEmpty)
-            .toList();
+          .split('\n')
+          .where((element) => element.isNotEmpty)
+          .toList();
         for (String line in dataLines) {
           if (line.startsWith('data: ')) {
             final String data = line.substring(6);
@@ -108,6 +108,9 @@ class OpenAiApi {
       onError: (error, stackTrace) {
         controller.addError(error, stackTrace);
       }); // response.stream.listen
+    },
+    onError: (error, stackTrace) {
+      controller.addError(error, stackTrace);
     }); // httpClient.send(request).then
 
     return controller.stream;

lib/api/openai_api.dart

@@ -29,7 +29,7 @@ class ChatMessage {
 
 class ChatRequest {
   /// ID of the model to use. Currently, only gpt-3.5-turbo and gpt-3.5-turbo-0301 are supported.
-  final String model = 'gpt-3.5-turbo-0301';
+  final String model = 'gpt-3.5-turbo';
   /// The messages to generate chat completions for
   final List<ChatMessage> messages;
   ///

lib/models/chat.dart

@@ -73,6 +73,15 @@ class ChatService {
     return conversation;
   }
 
+  Future _handleErrorGetResponseStream(dynamic error, Conversation conversation) async {
+    conversation.error = error.toString();
+    if (conversation.error.startsWith('Exception: '))
+      conversation.error = conversation.error.substring(11);
+    conversation.messages.last.isError = true;
+    conversation.lastUpdated = DateTime.now();
+    await updateConversation(conversation);
+  }
+
   Stream<Conversation> getResponseStreamFromServer(Conversation conversation) {
     final conversationStream = StreamController<Conversation>();
 
@@ -82,30 +91,23 @@ class ChatService {
     var messages = conversation.messages.map((e) => e.toChatMessage()).toList();
     messages.insert(0, systemMessage);
 
-    try {
-      var responseStream = _apiServer.chatCompletionStream(messages);
-      responseStream.listen((chatStream) {
-        if (chatStream.choices[0].delta.role.isNotEmpty)
-          conversation.messages.add(ConversationMessage(chatStream.choices[0].delta.role, ''));
-        if (chatStream.choices[0].delta.content.isNotEmpty)
-          conversation.messages.last.content += chatStream.choices[0].delta.content;
-        conversation.lastUpdated = DateTime.now();
-        updateConversation(conversation);
-        conversationStream.add(conversation);
-      },
-      onDone: () {
-        conversationStream.close();
-      });
-    } catch (e) {
-      // drop 'Exception: '
-      conversation.error = e.toString();
-      if (conversation.error.startsWith('Exception: '))
-        conversation.error = conversation.error.substring(11);
-      conversation.messages.last.isError = true;
+    var responseStream = _apiServer.chatCompletionStream(messages);
+    responseStream.listen((chatStream) {
+      if (chatStream.choices[0].delta.role.isNotEmpty)
+        conversation.messages.add(ConversationMessage(chatStream.choices[0].delta.role, ''));
+      if (chatStream.choices[0].delta.content.isNotEmpty)
+        conversation.messages.last.content += chatStream.choices[0].delta.content;
       conversation.lastUpdated = DateTime.now();
-      updateConversation(conversation);
       conversationStream.add(conversation);
-    }
+    },
+    onDone: () async {
+      await updateConversation(conversation);
+      conversationStream.close();
+    },
+    onError: (error) async {
+      await _handleErrorGetResponseStream(error, conversation);
+      conversationStream.add(conversation);
+    });
 
     return conversationStream.stream;
   }

lib/services/chat_service.dart

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.2+1
+version: 1.0.3+1
 
 environment:
   sdk: '>=2.19.3 <3.0.0'