Update app.py

app.py

@@ -6,7 +6,7 @@ from threading import Thread
 
 import dash
 import dash_bootstrap_components as dbc
-from dash import dcc, html, Input, Output, State, callback
+from dash import dcc, html, Input, Output, State, callback, MATCH, ALL
 from dash.exceptions import PreventUpdate
 from PyPDF2 import PdfReader, PdfWriter
 
@@ -37,13 +37,17 @@ app.layout = dbc.Container([
     html.Div(id='pdf-name'),
     dbc.Card([
         dbc.CardBody([
-            dbc.Input(id='page-range', type='text', placeholder='Enter page range (e.g., 1-3)'),
+            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"),
+            ]),
             dbc.Button("Add Range", id='add-range', color="secondary", className="mt-2"),
-            html.Div(id='ranges-list'),
         ])
     ], 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"),  # Changed from dcc.Progress to dbc.Progress
+    dbc.Progress(id='progress-bar', className="my-3"),
     dbc.Button("Download ZIP", id='download-button', color="success", className="mt-3", disabled=True),
     dcc.Download(id="download-zip"),
 ], fluid=True)
@@ -60,16 +64,28 @@ def update_output(contents, filename):
     return "No file selected", True
 
 @callback(
-    Output('ranges-list', 'children'),
+    Output('ranges-container', 'children'),
     Input('add-range', 'n_clicks'),
-    State('page-range', 'value'),
-    State('ranges-list', 'children')
+    Input({'type': 'remove-range', 'index': ALL}, 'n_clicks'),
+    State('ranges-container', 'children'),
+    prevent_initial_call=True
 )
-def add_range(n_clicks, new_range, existing_ranges):
-    if n_clicks is None or not new_range:
-        return existing_ranges or []
-    new_item = html.Div(f"Range: {new_range}")
-    return existing_ranges + [new_item] if existing_ranges else [new_item]
+def manage_ranges(add_clicks, remove_clicks, existing_ranges):
+    ctx = dash.callback_context
+    triggered_id = ctx.triggered[0]['prop_id'].split('.')[0]
+
+    if triggered_id == 'add-range':
+        new_index = len(existing_ranges)
+        new_range = dbc.Row([
+            dbc.Col(dbc.Input(id={'type': 'range-input', 'index': new_index}, type='text', placeholder='Enter page range (e.g., 1-3)'), width=10),
+            dbc.Col(dbc.Button("Remove", id={'type': 'remove-range', 'index': new_index}, color="danger", size="sm"), width=2),
+        ], className="mb-2")
+        existing_ranges.append(new_range)
+    elif 'remove-range' in triggered_id:
+        remove_index = json.loads(triggered_id)['index']
+        existing_ranges = [range for range in existing_ranges if json.loads(range['props']['children'][1]['props']['children']['props']['id'])['index'] != remove_index]
+
+    return existing_ranges
 
 def process_pdf(contents, filename, ranges):
     global generated_file, progress
@@ -110,14 +126,14 @@ def process_pdf(contents, filename, ranges):
     Input('split-button', 'n_clicks'),
     State('upload-pdf', 'contents'),
     State('upload-pdf', 'filename'),
-    State('ranges-list', 'children'),
+    State({'type': 'range-input', 'index': ALL}, 'value'),
     prevent_initial_call=True
 )
 def split_pdf(n_clicks, contents, filename, ranges):
     if not contents or not ranges:
         raise PreventUpdate
     
-    ranges = [r['props']['children'].split(': ')[1] for r in ranges]
+    ranges = [r for r in ranges if r]  # Filter out empty ranges
     thread = Thread(target=process_pdf, args=(contents, filename, ranges))
     thread.start()