Race condition causes sorters to be reset if set after updating data

[philippjfr]

When pagination is disabled the request that fetches new pages gets triggered when setting new data. This request also sends the sorters, which are reset to empty after the data is updated. Therefore the sorters are reset after updating the data:

import pandas as pd
import panel as pn

df1 = pd.DataFrame({
    'A': [1, 2, 3],
    'B': [4, 5, 6],
})

df2 = pd.DataFrame({
    'A': [10, 20, 30],
    'B': [40, 50, 60],
})

dfs = {
    'df1': df1,
    'df2': df2.iloc[:1],
}

sorters = {'df1': [], 'df2': []}

def sorting_callback(event):
    print('sorting_callback', event)
    sorters[dropdown.value] = event.new
    print('sorters', sorters)

table = pn.widgets.Tabulator(
    value=None,
    pagination='remote',
    page_size=2
)

def dropdown_callback(event):
    print('dropdown_callback', event)
    new_table = event.new
    print('sorters', sorters)
    table.value = dfs[new_table]
    table.sorters = sorters[new_table]

table.param.watch(sorting_callback, 'sorters')

options = list(dfs.keys())
dropdown = pn.widgets.Select(
    options=options, width=200,
)
dropdown.param.watch(dropdown_callback, 'value', onlychanged=False)
dropdown.value = options[0]

tmpl = pn.template.MaterialTemplate()
tmpl.main.append(dropdown)
tmpl.main.append(table)
tmpl.servable()