add retry last chat message button

app.py

@@ -77,6 +77,7 @@ class RAGDemo(object):
             documents=docs, embedding=self.embedding
         )
         gr.Info("Vector database built successfully.")
+        print("Vector database built successfully.")
 
     def _init_settings(self, model_name, api_key, embedding_model, embedding_api_key, data_file):
         self._init_chat_model(model_name, api_key)
@@ -94,6 +95,8 @@ class RAGDemo(object):
         return resp['result']
 
     def _chat_qa(self, message, chat_history):
+        if not message:
+            return "", chat_history
         memory = ConversationBufferMemory(
             chat_memory=ChatMessageHistory(
                 messages=convert_chat_history_to_messages(chat_history)
@@ -108,9 +111,16 @@ class RAGDemo(object):
             verbose=True,
         )
         resp = qa.invoke(message)
+        print(f">>> {resp}")
         chat_history.append((message, resp['answer']))
         return "", chat_history
 
+    def _retry_chat_qa(self, chat_history):
+        message = ""
+        if chat_history:
+            message, _ = chat_history.pop()
+        return self._chat_qa(message, chat_history)
+
     def __call__(self):
         with gr.Blocks(title="🔥 RAG Demo") as demo:
             gr.Markdown("# RAG Demo\n\nbase on the [RAG learning note](https://www.jianshu.com/p/9792f1e6c3f9) and "
@@ -144,7 +154,9 @@ class RAGDemo(object):
             with gr.Tab("Chat RAG"):
                 chatbot = gr.Chatbot(label="chat with pdf")
                 input_msg = gr.Textbox(placeholder="input your question...", label="input")
-                clear_btn = gr.ClearButton([chatbot, input_msg])
+                with gr.Row():
+                    clear_btn = gr.ClearButton([chatbot, input_msg], value="🧹 Clear")
+                    retry_btn = gr.Button("♻️ Retry")
             initial_btn.click(
                 self._init_settings,
                 inputs=[model_name, api_key, embedding_model, embedding_api_key, data_file]
@@ -161,6 +173,12 @@ class RAGDemo(object):
                 inputs=[input_msg, chatbot],
                 outputs=[input_msg, chatbot]
             )
+
+            retry_btn.click(
+                self._retry_chat_qa,
+                inputs=chatbot,
+                outputs=[input_msg, chatbot]
+            )
         return demo