Only subset the selected data if the index row exists!

Fixes #1351

Author: schloerke

shiny/render/_data_frame.py

@@ -494,11 +494,13 @@ def _subset_data_view(selected: bool) -> pd.DataFrame:
                         # Use a `set` for faster lookups
                         selected_row_indices_set = set(cell_selection["rows"])
 
-                        # Subset the data view indices to only include the selected rows
+                        # Subset the data view indices to only include the selected rows that are in the data
                         data_view_indices = [
                             index
                             for index in data_view_indices
                             if index in selected_row_indices_set
+                            and index
+                            in data.index  # pyright: ignore[reportUnknownMemberType]
                         ]
 
                 return data.iloc[data_view_indices]

tests/playwright/shiny/bugs/1351-render-data-frame/app.py

@@ -0,0 +1,49 @@
+import pandas as pd
+
+from shiny import App, Inputs, reactive, render, ui
+
+app_ui = ui.page_fluid(
+    ui.markdown(
+        """
+    ## Description
+
+    When you add a row, click on it and click the clear button you get:
+
+
+    """
+    ),
+    ui.input_action_button("add_row", "Add row"),
+    ui.input_action_button("clear_table", "Clear table"),
+    ui.output_text_verbatim("number_of_selected_rows"),
+    ui.output_data_frame("df1"),
+)
+
+
+def server(input: Inputs):
+    df = reactive.Value(pd.DataFrame(columns=["A", "B"]))
+
+    @render.data_frame
+    def df1():
+        return render.DataGrid(df(), selection_mode="rows")
+
+    @reactive.effect
+    @reactive.event(input.add_row)
+    def _():
+        old_df = df()
+        new_df = pd.concat(  # pyright: ignore[reportUnknownMemberType]
+            [old_df, pd.DataFrame([[1, 2]], columns=["A", "B"])]
+        )
+        df.set(new_df)
+
+    @render.text
+    def number_of_selected_rows():
+        df_selected = df1.data_view(selected=True)
+        return f"Selected rows: {len(df_selected)}"
+
+    @reactive.effect
+    @reactive.event(input.clear_table)
+    def _():
+        df.set(pd.DataFrame(columns=["A", "B"]))
+
+
+app = App(app_ui, server)

tests/playwright/shiny/bugs/1351-render-data-frame/test_1351_selected_row.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+from conftest import ShinyAppProc
+from controls import InputActionButton, OutputDataFrame, OutputTextVerbatim
+from playwright.sync_api import Page
+
+
+def test_row_selection(page: Page, local_app: ShinyAppProc) -> None:
+    page.goto(local_app.url)
+
+    df = OutputDataFrame(page, "df1")
+    add_row = InputActionButton(page, "add_row")
+    clear_table = InputActionButton(page, "clear_table")
+    selected_rows = OutputTextVerbatim(page, "number_of_selected_rows")
+
+    df.expect_n_row(0)
+    selected_rows.expect_value("Selected rows: 0")
+
+    add_row.click()
+
+    df.expect_n_row(1)
+    selected_rows.expect_value("Selected rows: 0")
+
+    df.cell_locator(0, 0).click()
+    df.select_rows([0])
+
+    df.expect_n_row(1)
+    selected_rows.expect_value("Selected rows: 1")
+
+    clear_table.click()
+    selected_rows.expect_value("Selected rows: 0")
+
+    bad_error_lines = [line for line in local_app.stderr._lines if "INFO:" not in line]
+    assert len(bad_error_lines) == 0, bad_error_lines