ipywidgets not working in dev mode

[rsinha25]

Hi,

I am getting this error on console when I run JLab in dev mode, while using ipywidgets:

import ipywidgets as ipyw
ipyw.Text("hello")

Uncaught (in promise) Error: Object 'jupyter.widget' not found in registry
    at default.js:1469
    at Promise (<anonymous>)
    at Object.loadObject (default.js:1448)
    at DefaultKernel._handleCommOpen (default.js:897)
    at DefaultKernel._onWSMessage (default.js:729)
    at WebSocket._ws.onmessage (default.js:653)

However it works perfectly fine when I start jlab normally.
Any help with this?

[maartenbreddels]

Jupyter lab requires running extra commands, it's better to wait a few days for the for the new jlab release. But if you want, you should get a working version if you do:

conda create -n jupytercon7 jupyterlab traittypes pillow
source activate jupytercon7

pip install --pre ipywidgets bqplot ipyleaflet ipyvolume pythreejs ipywebrtc
jupyter nbextension enable --sys-prefix --py widgetsnbextension
jupyter nbextension enable --sys-prefix --py bqplot
jupyter nbextension enable --sys-prefix --py ipyleaflet
jupyter nbextension enable --sys-prefix --py ipyvolume
jupyter nbextension enable --sys-prefix --py pythreejs
jupyter nbextension enable --sys-prefix --py ipywebrtc

jupyter labextension install @jupyter-widgets/jupyterlab-manager@0.25.10
jupyter labextension install jupyterlab-volume@0.1.0
jupyter labextension install jupyterlab-webrtc@0.2.1

Maybe you should install ipywidgets==7.0.0rc2 for this, the relase (just a day out) may not work with this set of commands.

[maartenbreddels]

Sorry, misread your first msg.

[rsinha25]

Here are the steps I did:

git clone JLab
cd jlab
pip install -e .
npm install
pip install ipywidgets --pre
jupyter labextension install @jupyter-widgets/jupyterlab-manager
npm run build:main

jupyter lab

ipywidgets work fine

jupyter lab --dev-mode

Get "A Jupyter Widget" on notebook and

Uncaught (in promise) Error: Object 'jupyter.widget' not found in registry
    at main.bundle.js:196343
    at Promise (<anonymous>)
    at Object.loadObject (main.bundle.js:196322)
    at DefaultKernel._handleCommOpen (main.bundle.js:195771)
    at DefaultKernel._onWSMessage (main.bundle.js:195603)
    at WebSocket._ws.onmessage (main.bundle.js:195527)

on console

run jupyter lab again, now gives the same errors.

[maartenbreddels]

Strange, for 0.26.5 it works (with latest release).

[rsinha25]

Did you try with dev mode?

[maartenbreddels]

Yes, first normal, then dev, both work (ipywidgets and ipyvolume)

[rsinha25]

Alright. Let me try that. Thanks :)

[rsinha25]

Just checked out to v0.26.5, found same behaviour

git checkout v0.26.5
npm install
npm run build:main

jupyter lab

Works fine

jupyter lab --dev-mode

Uncaught (in promise) Error: Object 'jupyter.widget' not found in registry
    at default.js:1468
    at Promise (<anonymous>)
    at Object.loadObject (default.js:1447)
    at DefaultKernel._handleCommOpen (default.js:897)
    at DefaultKernel._onWSMessage (default.js:729)
    at WebSocket._ws.onmessage (default.js:653)

on console.

[jasongrout]

Widgets work with jlab 0.26, and haven't yet been updated to work with the latest master. Would you like to help update them to jlab 0.27 when it is released (probably on Monday)?

[rsinha25]

@jasongrout Sure 👍

[jasongrout]

We made a release of widgets for jlab 0.27 now, so jupyter labextension install @jupyter-widgets/jupyterlab-manager should work in jlab 0.27.