Tabulator with frozen_rows scrolling/paging to top when updating content

[sylvaint]

ALL software version info

panel 1.4.2

Description of expected behavior and the observed behavior

With Tabulator using pagination and frozen_rows.
When updating the data, the page snaps back to page 1 regardless of where the paging was whenever the update comes. Removing the frozen row, it behaves as expected.

Same behavior without paging using a scrollbar in Tabulator instead.

Also same behavior when using patch instead of writing the complete dataframe.

Complete, minimal, self-contained example code that reproduces the issue

import panel as pn
import numpy as np
import pandas as pd

pn.extension('tabulator')

def create_random_dataframe(n_rows):
    """Create a DataFrame with n_rows and 5 columns, where the first column is a constant 1 to n_rows and the rest are filled with random numbers."""
    # Define the column names
    columns = ['A', 'B', 'C', 'D', 'E']
    # Generate a DataFrame with the first column being 1 to n_rows and the rest random
    df = pd.DataFrame(np.random.rand(n_rows, 4), columns=columns[1:])
    df.insert(0, 'A', range(1, n_rows + 1))  # Insert the constant column at position 0 with values 1 to n_rows
    return df

df_data = create_random_dataframe(50)

# with frozen_rows 0, Tabulator will snap back to page 1 at every update
df_tab = pn.widgets.Tabulator(df_data,hidden_columns=['index'], layout='fit_data_fill', frozen_rows=[0], sortable=False, disabled=True, pagination='local', page_size=10)

# without frozen_rows set to 0 Tabulator will remain in whatever page it was after an update
# df_tab = pn.widgets.Tabulator(df_data,hidden_columns=['index'], layout='fit_data_fill', sortable=False, disabled=True, pagination='local', page_size=10)

def update_data():
    df_data = create_random_dataframe(50)
    df_tab.value = df_data

pn.state.add_periodic_callback(update_data, period=2000, start=True)

layout = pn.template.FastListTemplate(
    site="my site",
    title="Tabulator",
    accent_base_color='#d78929',
    header_background='#d78929',
    main=[pn.Column(df_tab)],
)
layout.servable()

Screenshots or screencasts of the bug in action

tabulator_paging.mp4

tabulator_scroll_floatpanel.mp4

[philippjfr]

To avoid the reset here you should stream data and set the rollover:

def update_data():
    df_tab.stream(create_random_dataframe(50), follow=True, rollover=50)

[sylvaint]

Thank you so much for this. I will try this shortly.

[philippjfr]

Oh sorry, I should have said, that also doesn't behave properly as of right now but #7084 will fix that.

[sylvaint]

Got it thanks. Will monitor #7084

[sylvaint]

Same issue as before. Streaming with follow is not a solution.
This is the desired behavior but it does not work with a frozen row:

Screen.Recording.2024-09-20.at.5.11.10.PM.mov

Even better if it would work without paging and a scrollbar.