Update app.py

app.py

@@ -54,10 +54,10 @@ if pdf_source == "Upload a PDF file":
         st.session_state.vector_created = False
 
 elif pdf_source == "Enter a PDF URL":
-    pdf_url = st.text_input("Enter PDF URL:", value="https://arxiv.org/pdf/2406.06998", key="pdf_url")
+    pdf_url = st.text_input("Enter PDF URL:", value="https://arxiv.org/pdf/2406.06998", key="pdf_url", on_change=lambda: st.session_state.update(trigger_download=True))
 
-    # ✅ Button to manually trigger the download
-    if st.button("Download and Process PDF") or pdf_url.strip() != "" and st.session_state.get("pdf_path") is None:
+    # Button OR Enter key will trigger download
+    if st.button("Download and Process PDF") or st.session_state.get("trigger_download", False):
         with st.spinner("Downloading PDF..."):
             try:
                 response = requests.get(pdf_url)
@@ -70,6 +70,7 @@ elif pdf_source == "Enter a PDF URL":
                     st.session_state.pdf_loaded = False
                     st.session_state.chunked = False
                     st.session_state.vector_created = False
+                    st.session_state.trigger_download = False  # Reset trigger
 
                     st.success("✅ PDF Downloaded Successfully!")
                 else: