Panel not working with mapwidget.cesium: Class null not found in module @jupyter-widgets/base@2.0.0 #88

[MarcSkovMadsen]

It is unclear to me which package is responsible for this error. So I've crossposted to

• Not working with mapwidget.cesium: Class null not found in module @jupyter-widgets/base@2.0.0 bokeh/ipywidgets_bokeh#88

Environment Information

• mapwidget version: 0.1.2
• Python version: 3.9
• Operating System: Windows

Description

I would like to use Panel with mapwidget.cesium. Panel works with (some) ipywidgets via ipywidgets-bokeh.

Exception

Class null not found in module @jupyter-widgets/base@2.0.0      ipywidgets_bokeh.js?v=59296d23d623ce0adf7675d22156e83b1248c8508135a65dd8a9e38c497e94a8:8 

Reproducible Example

pip install panel==0.14.1 ipywidgets-bokeh==1.3.0 mapwidget==0.1.2

Other versions: ipywidgets-8.0.5 jupyterlab-widgets-3.0.6 widgetsnbextension-4.0.6 anywidget-0.2.0

mapwidget_app.py

import os
import mapwidget.cesium as mapwidget
import panel as pn

pn.extension("ipywidgets")

try:
    token = os.environ['CESIUM_TOKEN']
except KeyError as ex:
    raise EnvironmentError(
        "CESIUM_TOKEN environment variable not set. "
        "Sign up for free and get a free Cesium token here https://ion.cesium.com/signup/"
        ) from ex

cesium_map = mapwidget.Map(center=[40.70605, -74.01177], altitude=600, height='600px', token=token)
pn.panel(cesium_map).servable()

panel serve mapwidget_app.py

Open: http://localhost:5006/mapwidget_app and see the exception in the browsers console.

[MarcSkovMadsen]

I can see that Panel + ipywidgets-bokeh does not work with anywidget. So this is the more fundamental issue to solve. See bokeh/ipywidgets_bokeh#89.

[giswqs]

This is probably the upstream issue like ipywidgets or Panel. Anywidget does not use ipywidgets as an dependency. It should be platform agnostic.

[MarcSkovMadsen]

Thanks. It seems to do though 👍

[giswqs]

My bad. Anyway, I don't think anywidget is responsible for the issue. Let's wait for the maintainer respond.

[MarcSkovMadsen]

It works now after fixes in ipywidgets_bokeh. Thanks for helping out.

Would you like a PR to the docs describing that mapwidget.cesium works with Panel including a small example?`

mapwidget-cesium2.mp4

# pip install panel ipywidgets_bokeh mapwidget
import os

import mapwidget.cesium as mapwidget

import panel as pn

pn.extension("ipywidgets")

try:
    token = os.environ["CESIUM_TOKEN"]
except KeyError as ex:
    raise EnvironmentError(
        "CESIUM_TOKEN environment variable not set. "
        "Sign up for free and get a free Cesium token here https://ion.cesium.com/signup/"
    ) from ex

cesium_map = mapwidget.Map(
    center=[40.70605, -74.01177], height="650px", altitude=600, token=token
)

component = pn.panel(cesium_map, sizing_mode="stretch_width")

description = """# MapWidget

Custom Jupyter widgets for creating interactive 2D/3D maps using popular JavaScript libraries with bidirectional communication, such as `Cesium`, `Mapbox`, `MapLibre`, `Leaflet`, and `OpenLayers`.

By **Qiusheng Wu**

<img src="https://avatars.githubusercontent.com/u/5016453?v=4" style="width:100%;"> 

# Cesium

Cesium is the open platform for software applications designed to unleash the power of 3D data.

<img src="https://images.prismic.io/cesium/a4dc3936-e083-4337-ba48-bb5bba78b2a1_ion_color_white.png" style="width:100%;"> 
"""

pn.template.FastListTemplate(
    logo="https://panel.holoviz.org/_static/logo_horizontal_dark_theme.png",
    title="Works with mapwidget.cesium",
    main=[component],
    sidebar=[description],
).servable()

panel serve app.py --autoreload --show

[giswqs]

That would be great. Thank you