Update app.py

app.py

@@ -41,21 +41,16 @@ app.layout = dbc.Container([
         },
         multiple=False
     ),
-    html.Div(id='pdf-name'),
+    dbc.Spinner(html.Div(id='pdf-name'), color="primary", type="grow"),
     dbc.Card([
         dbc.CardBody([
-            html.Div(id='ranges-container', children=[
-                dbc.Row([
-                    dbc.Col(dbc.Input(id={'type': 'range-input', 'index': 0}, type='text', placeholder='Enter page range (e.g., 1-3)'), width=10),
-                    dbc.Col(dbc.Button("Remove", id={'type': 'remove-range', 'index': 0}, color="danger", size="sm"), width=2),
-                ], className="mb-2"),
-            ]),
+            html.Div(id='ranges-container', children=[]),
             dbc.Button("Add Range", id='add-range', color="secondary", className="mt-2"),
         ])
     ], className="my-3"),
     dbc.Button("Split PDF", id='split-button', color="primary", className="mt-3", disabled=True),
     dbc.Progress(id='progress-bar', className="my-3"),
-    dbc.Button("Download ZIP", id='download-button', color="success", className="mt-3"),
+    dbc.Button("Download ZIP", id='download-button', color="success", className="mt-3", disabled=True),
     dcc.Download(id="download-zip"),
     html.Div(id='log-output', style={'whiteSpace': 'pre-line'}),
 ], fluid=True)
@@ -63,17 +58,22 @@ app.layout = dbc.Container([
 @callback(
     Output('pdf-name', 'children'),
     Output('split-button', 'disabled'),
+    Output('ranges-container', 'children'),
     Input('upload-pdf', 'contents'),
     Input('upload-pdf', 'filename')
 )
 def update_output(contents, filename):
     if contents is not None:
         logger.info(f"PDF uploaded: {filename}")
-        return html.Div(f"Uploaded: {filename}"), False
-    return "", True
+        initial_range = dbc.Row([
+            dbc.Col(dbc.Input(id={'type': 'range-input', 'index': 0}, type='text', placeholder='Enter page range (e.g., 1-3)'), width=10),
+            dbc.Col(dbc.Button("Remove", id={'type': 'remove-range', 'index': 0}, color="danger", size="sm"), width=2),
+        ], className="mb-2")
+        return html.Div(f"Uploaded: {filename}"), False, [initial_range]
+    return "", True, []
 
 @callback(
-    Output('ranges-container', 'children'),
+    Output('ranges-container', 'children', allow_duplicate=True),
     Input('add-range', 'n_clicks'),
     State('ranges-container', 'children'),
     prevent_initial_call=True
@@ -105,6 +105,7 @@ def remove_range(n_clicks, existing_ranges):
 @callback(
     Output('progress-bar', 'value'),
     Output('log-output', 'children'),
+    Output('download-button', 'disabled'),
     Input('split-button', 'n_clicks'),
     State('upload-pdf', 'contents'),
     State('upload-pdf', 'filename'),
@@ -126,7 +127,7 @@ def split_pdf(n_clicks, contents, filename, ranges):
     thread = Thread(target=process_pdf, args=(contents, filename, ranges))
     thread.start()
     
-    return 0, "PDF splitting process started. Check console for detailed logs."
+    return 0, "PDF splitting process started. Check console for detailed logs.", True
 
 def process_pdf(contents, filename, ranges):
     global progress, generated_file
@@ -167,6 +168,7 @@ def process_pdf(contents, filename, ranges):
 @callback(
     Output('progress-bar', 'value', allow_duplicate=True),
     Output('log-output', 'children', allow_duplicate=True),
+    Output('download-button', 'disabled', allow_duplicate=True),
     Input('progress-bar', 'value'),
     prevent_initial_call=True
 )
@@ -174,12 +176,12 @@ def update_progress(value):
     global progress
     if progress == 100:
         logger.info("PDF splitting completed")
-        return 100, "PDF splitting completed. Click 'Download ZIP' to get your files."
+        return 100, "PDF splitting completed. Click 'Download ZIP' to get your files.", False
     elif progress == -1:
         logger.error("PDF splitting failed")
-        return 0, "Error occurred during PDF splitting. Check console for details."
+        return 0, "Error occurred during PDF splitting. Check console for details.", True
     else:
-        return progress, f"Processing... {progress:.0f}% complete"
+        return progress, f"Processing... {progress:.0f}% complete", True
 
 @callback(
     Output("download-zip", "data"),