Update app.py via AI Editor

app.py

@@ -142,13 +142,7 @@ server = app.server
 app.title = "Intelligent PDF Splitter"
 
 def get_split_results_placeholder():
-    # Always render split-btn (disabled) so Dash Input/Output registration never fails
-    return dbc.Row([
-        dbc.Col(
-            dbc.Button("Split PDF", id='split-btn', color='primary', className='mb-3 mt-2', n_clicks=0, style={'width': '180px', 'fontWeight': 'bold'}, disabled=True),
-            width=12, style={'display': 'flex', 'justifyContent': 'center'}
-        )
-    ])
+    return html.Div("", id="split-results-inner")
 
 app.layout = dbc.Container(
     [
@@ -178,6 +172,12 @@ app.layout = dbc.Container(
                                         accept='.pdf'
                                     ),
                                     html.Div(id='file-info', className='mb-4'),
+                                    dbc.Button(
+                                        "Split PDF", id='split-btn',
+                                        color='primary', className='mb-3 mt-2',
+                                        n_clicks=0, style={'width': '180px', 'fontWeight': 'bold'},
+                                        disabled=True
+                                    ),
                                     dbc.Button("Clear Session", id='clear-session', color='secondary', className='mt-2 mb-2'),
                                     dcc.Loading(
                                         id="loading", type="default",
@@ -199,6 +199,7 @@ app.layout = dbc.Container(
 
 @app.callback(
     Output('file-info', 'children'),
+    Output('split-btn', 'disabled'),
     Output('split-results', 'children'),
     Output('session-store', 'data'),
     Input('upload-pdf', 'contents'),
@@ -223,7 +224,7 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
     if trigger == 'clear-session':
         clean_session(session_id)
         resp_data = {}
-        return "", get_split_results_placeholder(), resp_data
+        return "", True, get_split_results_placeholder(), resp_data
 
     # Handle Delete Upload (detect ANY delete button press)
     delete_pressed = False
@@ -242,15 +243,15 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
         if os.path.exists(session_dir):
             for file in os.listdir(session_dir):
                 os.remove(os.path.join(session_dir, file))
-        return "", get_split_results_placeholder(), {}
+        return "", True, get_split_results_placeholder(), {}
 
     # Handle Upload
     if trigger == 'upload-pdf':
         if not contents:
-            return "", get_split_results_placeholder(), {}
+            return "", True, get_split_results_placeholder(), {}
 
         if not allowed_file(filename):
-            return html.Div("Only .pdf files are allowed.", style={'color': 'red'}), get_split_results_placeholder(), {}
+            return html.Div("Only .pdf files are allowed.", style={'color': 'red'}), True, get_split_results_placeholder(), {}
 
         try:
             header, b64data = contents.split(',', 1)
@@ -272,16 +273,10 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
                     width=3, style={'display': 'flex', 'justifyContent': 'end'}
                 )
             ], className='mb-3', align='center', style={'marginTop': "15px", 'marginBottom': '25px'})
-            split_results = dbc.Row([
-                dbc.Col(
-                    dbc.Button("Split PDF", id='split-btn', color='primary', className='mb-3 mt-2', n_clicks=0, style={'width': '180px', 'fontWeight': 'bold'}),
-                    width=12, style={'display': 'flex', 'justifyContent': 'center'}
-                )
-            ])
-            return file_info, split_results, session_data
+            return file_info, False, get_split_results_placeholder(), session_data
         except Exception as e:
             logging.error(f"Error processing PDF: {e}")
-            return html.Div(f"Error: {e}", style={'color': 'red'}), get_split_results_placeholder(), {}
+            return html.Div(f"Error: {e}", style={'color': 'red'}), True, get_split_results_placeholder(), {}
 
     # Restore after upload (before split)
     if session_data.get('orig_filename') and not session_data.get('split_files'):
@@ -292,23 +287,18 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
                 width=3, style={'display': 'flex', 'justifyContent': 'end'}
             )
         ], className='mb-3', align='center', style={'marginTop': "15px", 'marginBottom': '25px'})
-        split_results = dbc.Row([
-            dbc.Col(
-                dbc.Button("Split PDF", id='split-btn', color='primary', className='mb-3 mt-2', n_clicks=0, style={'width': '180px', 'fontWeight': 'bold'}),
-                width=12, style={'display': 'flex', 'justifyContent': 'center'}
-            )
-        ])
-        return file_info, split_results, session_data
+        return file_info, False, get_split_results_placeholder(), session_data
 
     # Handle Split
     if trigger == 'split-btn':
         orig_filename = session_data.get('orig_filename')
         if not orig_filename:
-            return html.Div("No file to split.", style={'color': 'red'}), get_split_results_placeholder(), session_data
+            return html.Div("No file to split.", style={'color': 'red'}), True, get_split_results_placeholder(), session_data
         pdf_path = os.path.join(session_dir, orig_filename)
         if not os.path.exists(pdf_path):
-            return html.Div("Uploaded file not found. Please upload again.", style={'color': 'red'}), get_split_results_placeholder(), {}
+            return html.Div("Uploaded file not found. Please upload again.", style={'color': 'red'}), True, get_split_results_placeholder(), {}
         try:
+            logging.info(f"Splitting PDF for session {session_id} on user request.")
             with lock:
                 split_files = intelligent_pdf_split(pdf_path, session_dir)
                 zip_path = make_zip_of_splits(split_files, session_dir)
@@ -330,16 +320,16 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
                 "Download All (ZIP)", color="primary", size="lg", className='mb-3 mt-4',
                 href=f"/download_zip/{session_id}/split_files.zip"
             )
-            results = [
+            results = html.Div([
                 html.H5("Split Files:"),
                 split_files_list,
                 html.Div(download_zip_btn, style={'marginTop': '30px'})
-            ]
+            ], id="split-results-inner")
             logging.info(f"PDF split into {len(split_files)} chunks for session {session_id}, zip ready.")
-            return file_info, results, session_data
+            return file_info, False, results, session_data
         except Exception as e:
             logging.error(f"Error splitting PDF: {e}")
-            return html.Div(f"Error: {e}", style={'color': 'red'}), get_split_results_placeholder(), session_data
+            return html.Div(f"Error: {e}", style={'color': 'red'}), False, get_split_results_placeholder(), session_data
 
     # Restore after split
     if session_data.get('split_files'):
@@ -361,14 +351,14 @@ def handle_upload(contents, filename, clear_n, delete_upload_n_list, split_n, se
             "Download All (ZIP)", color="primary", size="lg", className='mb-3 mt-4',
             href=f"/download_zip/{session_id}/split_files.zip"
         )
-        results = [
+        results = html.Div([
             html.H5("Split Files:"),
             split_files_list,
             html.Div(download_zip_btn, style={'marginTop': '30px'})
-        ]
-        return file_info, results, session_data
+        ], id="split-results-inner")
+        return file_info, False, results, session_data
 
-    return "", get_split_results_placeholder(), session_data
+    return "", True, get_split_results_placeholder(), session_data
 
 @app.server.route('/download_zip/<session_id>/<filename>')
 def download_zip_file(session_id, filename):