Tự động điền string ' ' nếu chat text empty

app.py

@@ -285,7 +285,7 @@ class ChatService:
                 else:
                     # For text messages, use form-data format as expected by API
                     data = {
-                        "message": message,
+                        "message": message if message and message.strip() else " ",
                         "session_id": state.session_id,
                         "debug": "Normal",
                         "product_model_search": str(state.product_model_search).lower(),
@@ -1064,13 +1064,15 @@ async def main(message: cl.Message):
                 image_path = element.path
                 break
     
+    user_message = message.content if message.content and message.content.strip() else " "
+    
     # Create initial message for animation
     msg = cl.Message(content="", author="assistant")
     await msg.send()
     
     # Create concurrent tasks for animation and API call
     animation_task = asyncio.create_task(run_typing_animation(msg))
-    api_task = asyncio.create_task(ChatService.respond_to_chat(app_state, message.content, image_path))
+    api_task = asyncio.create_task(ChatService.respond_to_chat(app_state, user_message, image_path))
     
     try:
         # Wait for API response (this will complete first usually)