Fix: Refactor demo creation into function for better error handling

app.py

@@ -921,40 +921,39 @@ IS_SPACES = (
     os.getenv("HF_SPACE_ID") is not None
 )
 
-# Create demo at module level (like HF docs example)
-# Initialize demo variable to None first (safety measure)  
+# CRITICAL: Initialize demo variable FIRST before any try/except
+# This ensures it always exists, even if initialization fails
 demo = None
 
-# Create demo at module level (like HF docs example)
-# This ensures Spaces can always find it when importing the module
-try:
-    if IS_SPACES:
-        logger.info("Initializing for Hugging Face Spaces...")
-    else:
-        logger.info("Initializing for local execution...")
-    
-    # Initialize with default args
-    parser = argparse.ArgumentParser()
-    parser.add_argument('--model', type=str, default='meta-llama/Llama-3.2-3B-Instruct')
-    parser.add_argument('--vector-db-dir', default='./chroma_db')
-    parser.add_argument('--data-dir', default='./Data Resources')
-    parser.add_argument('--max-new-tokens', type=int, default=1024)
-    parser.add_argument('--temperature', type=float, default=0.2)
-    parser.add_argument('--top-p', type=float, default=0.9)
-    parser.add_argument('--repetition-penalty', type=float, default=1.1)
-    parser.add_argument('--k', type=int, default=5)
-    parser.add_argument('--skip-indexing', action='store_true', default=True)
-    parser.add_argument('--verbose', action='store_true', default=False)
-    parser.add_argument('--share', action='store_true', default=False)
-    parser.add_argument('--server-name', type=str, default='0.0.0.0')
-    parser.add_argument('--server-port', type=int, default=7860)
-    parser.add_argument('--seed', type=int, default=42)
-    
-    args = parser.parse_args([])  # Empty args
-    args.skip_model_loading = IS_SPACES  # Skip model loading on Spaces, use Inference API
-    
-    # Create bot - handle initialization errors gracefully
+def _create_demo():
+    """Create the demo - separated into function for better error handling"""
     try:
+        logger.info("=" * 80)
+        logger.info("Starting demo creation...")
+        logger.info(f"IS_SPACES: {IS_SPACES}")
+        
+        # Initialize with default args
+        parser = argparse.ArgumentParser()
+        parser.add_argument('--model', type=str, default='meta-llama/Llama-3.2-3B-Instruct')
+        parser.add_argument('--vector-db-dir', default='./chroma_db')
+        parser.add_argument('--data-dir', default='./Data Resources')
+        parser.add_argument('--max-new-tokens', type=int, default=1024)
+        parser.add_argument('--temperature', type=float, default=0.2)
+        parser.add_argument('--top-p', type=float, default=0.9)
+        parser.add_argument('--repetition-penalty', type=float, default=1.1)
+        parser.add_argument('--k', type=int, default=5)
+        parser.add_argument('--skip-indexing', action='store_true', default=True)
+        parser.add_argument('--verbose', action='store_true', default=False)
+        parser.add_argument('--share', action='store_true', default=False)
+        parser.add_argument('--server-name', type=str, default='0.0.0.0')
+        parser.add_argument('--server-port', type=int, default=7860)
+        parser.add_argument('--seed', type=int, default=42)
+        
+        args = parser.parse_args([])  # Empty args
+        args.skip_model_loading = IS_SPACES  # Skip model loading on Spaces, use Inference API
+        
+        logger.info("Creating RAGBot...")
+        # Create bot - handle initialization errors gracefully
         bot = RAGBot(args)
         
         if bot.vector_retriever is None:
@@ -966,18 +965,20 @@ try:
             logger.warning("Vector database is empty. The chatbot may not find relevant documents.")
             logger.warning("This is OK for initial deployment - documents can be indexed later.")
         
+        logger.info("Creating interface...")
         # Create the demo interface directly at module level (like HF docs example)
         demo = create_interface(bot, use_inference_api=IS_SPACES)
         logger.info(f"Demo created successfully: {type(demo)}")
+        return demo
+        
     except Exception as bot_error:
-        logger.error(f"Error initializing RAGBot: {bot_error}", exc_info=True)
+        logger.error(f"Error initializing: {bot_error}", exc_info=True)
         import traceback
         error_trace = traceback.format_exc()
         logger.error(f"Full traceback: {error_trace}")
         
         # Create a demo that shows the error but still allows the interface to load
-        # This is critical - we MUST create a demo object for Spaces
-        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
+        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as error_demo:
             gr.Markdown(f"""
             # ⚠️ Initialization Error
             
@@ -995,31 +996,41 @@ try:
             - Make sure HF_TOKEN is set as a secret
             - Check the logs tab for detailed error messages
             
-            Please check the logs for more details.
+            **Error Details:**
+            ```
+            {error_trace[:1000]}...
+            ```
             """)
-        logger.info(f"Error demo created: {type(demo)}")
-        # Don't re-raise - let the demo be created so users can see the error
-    
-    # Verify demo was created
-    if demo is None:
-        logger.error("Demo is None after creation attempt!")
-        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
-            gr.Markdown("# Error: Demo was not created\n\nPlease check the logs.")
-    elif not isinstance(demo, (gr.Blocks, gr.Interface)):
-        logger.error(f"Demo is not a valid Gradio object: {type(demo)}")
-        with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
-            gr.Markdown(f"# Error: Invalid demo type\n\nType: {type(demo)}\n\nPlease check the logs.")
-    else:
-        logger.info(f"Demo created successfully: {type(demo)}")
-        logger.info("Demo validation passed - ready for Spaces")
+        logger.info(f"Error demo created: {type(error_demo)}")
+        return error_demo
+
+# Create demo at module level (like HF docs example)
+# This ensures Spaces can always find it when importing the module
+try:
+    demo = _create_demo()
+    logger.info("Demo creation completed")
 except Exception as e:
-    logger.error(f"Error creating demo: {e}", exc_info=True)
+    logger.error(f"CRITICAL: Error in demo creation wrapper: {e}", exc_info=True)
     import traceback
-    logger.error(f"Traceback: {traceback.format_exc()}")
+    error_trace = traceback.format_exc()
+    logger.error(f"Full traceback: {error_trace}")
     # Create a fallback error demo so Spaces doesn't show blank
-    with gr.Blocks() as demo:
-        gr.Markdown(f"# Error Initializing Chatbot\n\nAn error occurred while initializing the chatbot.\n\nError: {str(e)}\n\nPlease check the logs for details.")
-    logger.info(f"Error demo created: {type(demo)}")
+    with gr.Blocks(title="CGT-LLM-Beta RAG Chatbot") as demo:
+        gr.Markdown(f"""
+        # Error Initializing Chatbot
+        
+        A critical error occurred while initializing the chatbot.
+        
+        **Error:** {str(e)}
+        
+        **Traceback:**
+        ```
+        {error_trace[:1500]}...
+        ```
+        
+        Please check the logs for more details.
+        """)
+    logger.info(f"Fallback error demo created: {type(demo)}")
 
 # Final verification - ensure demo exists and is valid
 # This is CRITICAL for Spaces - the demo variable MUST exist and be a valid Gradio object