SelectionRangeSlider Options List Not Updating

[brendan0powers]

In some cases when changing the options of a SelectionRangeSlider, the options list is not updated. For this to occur, you must have both continuous_update set to True, and an index specified. I've seen similar behavior in react_ipywidgets 0.11 (ipywidgets 0.7) with the SelectMultiple widget. I believe it's some kind of race condition in the SelectionRangeSlider's JavaScript view, but I haven't been able to reproduce this issue with ipywidgets directly.

Test Case:
Click Update, and then try and adjust the slider range. The range remains 1-3, instead of updating to 1-10.
Set continuous_update to False, or remove the index, and the problem does not occur.

import reacton as react
import reacton.ipywidgets as w

@react.component()
def Test():
    options, setOptions = react.use_state(['1', '2', '3'])
    
    firstIndex = 0
    lastIndex = max(0, len(options)-1)
    
    def onClicked():
        setOptions([str(i) for i in range(1, 11)])
        print("what")
    
    print(options)
    
    with w.VBox() as vbox:
        w.Button(description="Update", on_click=onClicked)
        w.SelectionRangeSlider(
            description="Options",
            options=options,
            index=(firstIndex, lastIndex),
            continuous_update=True
        )
    
    return vbox

Test()

Software Versions:

python                          3.10.9
ipywidgets                    8.0.4
reacton                          1.2.2

[maartenbreddels]

I think this is an ipywidget bug.

import ipywidgets
options = ['1', '2', '3']
firstIndex, lastIndex = 1, 2

s = ipywidgets.SelectionRangeSlider(
            description="Options",
            options=options,
            index=(firstIndex, lastIndex),
            continuous_update=True
        )
def update(b):
    s.options = [str(k) for k in range(1,11)]
b = ipywidgets.Button(description="Update")
b.on_click(update)
display(b, s)

Since this behaves the same, do you agree?

Actually, Reacton can help you work around it, by using:

        w.SelectionRangeSlider(
            description="Options",
            options=options,
            index=(firstIndex, lastIndex),
            continuous_update=True
        ).key(repr(options))

Where the .key(..) function will make reacton not match this element to the widget with the previous options. It will create a new widget and destroy the old one. I guess there are better way that repr(options) though.

[brendan0powers]

Yeah, seems likely to be a ipywidgets bug. That example does not reproduce the issue for me, but I suspect it's a race condition on the ipywidgets browser side. I was unable to find a case that reproduced it before now. I'll file a bug with ipywidgets and include your example and a reacton example. Hopefully that's enough for them to go on.

The .key() workaround works great! I use id(optoins) since I replace the options array each it changes. Thanks!

[maartenbreddels]

Yes, id(..) in this case should be fine since the list will be created before the old once can be GC'ed, so you cannot end up with the same id/address.

[maartenbreddels]

I think the issue is solved.