Update app.py

state = gr.State({"chunks": [], "index": None, 'pdf_count':0})

with gr.Row():
with gr.Column(scale=1):
pdf_input = gr.File(label="Upload PDF", file_types=[".pdf"])
pdf_status = gr.Textbox(label="Status", interactive=False)

with gr.Column(scale=2):
with gr.row()
question = gr.Textbox(label="Your question", lines=2)
clear_button = gr.Button("Clear Question")

answer = gr.Textbox(label="Answer", lines=8)
ask_button = gr.Button("Ask")

app.py

@@ -147,25 +147,26 @@ def generate_answer(question, context):
 # ============================================================
 
 def load_pdf(file, state):
-    state["chunks"] = None
-    state["index"] = None
-
     if file is None:
         return "No file uploaded.", state
 
     try:
+        # Read and chunk the new PDF
         text = read_pdf(file)
-        chunks = chunk_text(text)
+        new_chunks = chunk_text(text)
 
-        if not chunks:
+        if not new_chunks:
             return "Could not extract text from PDF.", state
 
-        index, _ = build_vectorstore(chunks)
+        # Append to existing chunks
+        state["chunks"].extend(new_chunks)
 
-        state["chunks"] = chunks
+        # Rebuild vectorstore with ALL chunks
+        index, _ = build_vectorstore(state["chunks"])
         state["index"] = index
 
-        return f"PDF loaded successfully. {len(chunks)} chunks created.", state
+        state["pdf_count"] += 1
+        return f"PDF #{state['pdf_count']} added. Total chunks: {len(state['chunks'])}", state
 
     except Exception as e:
         return f"Error processing PDF: {e}", state
@@ -199,7 +200,7 @@ def answer_question(question, state):
 with gr.Blocks(title="PDF Q&A Chatbot") as demo:
     gr.Markdown("## 📄 PDF Q&A Chatbot\nUpload a PDF and ask questions about its content.")
 
-    state = gr.State({"chunks": None, "index": None})
+    state = gr.State({"chunks": [], "index": None, 'pdf_count':0})
 
     with gr.Row():
         with gr.Column(scale=1):
@@ -207,12 +208,17 @@ with gr.Blocks(title="PDF Q&A Chatbot") as demo:
             pdf_status = gr.Textbox(label="Status", interactive=False)
 
         with gr.Column(scale=2):
-            question = gr.Textbox(label="Your question", lines=2)
+            with gr.row()
+                question = gr.Textbox(label="Your question", lines=2)
+                clear_button = gr.Button("Clear Question")
+            
             answer = gr.Textbox(label="Answer", lines=8)
             ask_button = gr.Button("Ask")
+            
 
     pdf_input.upload(load_pdf, inputs=[pdf_input, state], outputs=[pdf_status, state])
     ask_button.click(answer_question, inputs=[question, state], outputs=answer)
+    clear_button.click(lambda: "", outputs=question)