`on_selection` callback seems to not get fired

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It seems the on_selection callback does not fire anymore. I've seen a number of open and closed issues back from 2020 discussing the usage of it, but based on the newest version 5.10.0 I cannot get anything to fire on a selection.

The simplest code example I could find (from https://github.com/plotly/plotly.py/issues/2698)

import plotly.graph_objects as go
import numpy as np

np.random.seed(1)
x = np.random.randn(500)

def on_selection_print(obj, points, selector):
    print(points.point_inds)

figure_widget = go.FigureWidget(data=[go.Histogram(x=x)])
figure_widget.update_layout(dragmode="select")    
figure_widget.data[0].on_selection(on_selection_print)
figure_widget.show()

Both running this in jupyter or as a python script, nothing seems to print.

I tried the latest docs on selection events but I couldn't actually get that example to run in jupyter or otherwise.

Am I just missing something simple?

Thanks!

Start by running the provided FigureWidget example in Jupyter and as a Python script, focusing on the figure's on_selection callback and dragmode="select" setup. Trace the selection event path and compare the behavior with the linked selection-events documentation and issue #2698; done means the callback behavior is explained and the reported example is fixed or its supported usage is clearly established.