Compatibility of jupyter-widgets/base with JupyterLab 1.2 and 2.0

[emmanuelle]

Hello! I hope this is the right place to open this issue.

With @nicolaskruchten we're trying to upgrade the plotlywidget JS package to work with JupyterLab 2.0 and running into a problem related to @jupyter-widgets/base ... Version 1.5.3 of our package depends on version 2.0.0 of @jupyter-widgets/base and works in JupyterLab 1.2, which is great. When we try to upgrade to version 3.0.0 we gain JupyterLab 2.0 support, but it no longer works with JupyterLab 1.2. Is this a known limitation? Is it intended that JS packages depending on @jupyter-widgets/base can work both with JupyterLab 1.2 and 2? Thank you :-).

[jasongrout]

See #2798 (comment)

Short answer: make the dependency ^2 || ^3

[nicolaskruchten]

Thanks @jasongrout! Unfortunately this doesn't appear to resolve our issue in JupyterLab 1.2... I still get the following output, which doesn't appear when depending on ^2.0.0:

[jasongrout]

Where is your PR?

[nicolaskruchten]

These are the changes I'm trying: plotly/plotly.py#2256

Note that package-lock.json bakes in the dependency on version 3, so I'm not sure how this ^2 || ^3 change makes things work when folks try to install... Maybe I'm just seeing this error because I'm running jupyter labextension install . from the plotlywidget directory?

[jasongrout]

Note that package-lock.json bakes in the dependency on version 3, so I'm not sure how this ^2 || ^3 change makes things work when folks try to install...

The package-lock.json is not used in JupyterLab. JLab will build its own dependency tree straight from the package.json, in consideration with other packages in the jlab build.

[jasongrout]

I tried making a dev installation of the plotly PR in jlab 1.2.7 to see if I could reproduce this, but ran into troubles when trying to create a plot: js error of "ReferenceError: require is not defined" from a line:

                require(["plotly"], function(Plotly) {
                    window.PLOTLYENV=window.PLOTLYENV || {};

Is that expected? Are there instructions for making a dev installation that cover installing the jlab plugin? I tried to follow https://github.com/plotly/plotly.py/blob/master/contributing.md

[nicolaskruchten]

That is... not expected, although it's been reported from time to time and not easily reproduced on our end :)

The way I install the dev version is what I had assumed is the standard way, which is to cd packages/javascript/plotlywidget && npm install && npm run build && jupyter labextension install . but I always have a nagging feeling that I'm doing it wrong :)

[nicolaskruchten]

Looks like the way I was testing things until now was not correct, and that the path @jasongrout suggested above does work if you install into a clean JLab 1.2 instance, see plotly/plotly.py#2261. I was downgrading from 2 to 1 using pip but I guess that leaves little bits hanging around somehow?

[jasongrout]

but I guess that leaves little bits hanging around somehow?

I think it can. I'd want to delete the jlab application directory if you downgraded to be sure - that's where jlab is built when you have extensions installed.

[jasongrout]

Sounds like this is resolved over in plotly/plotly.py#2261. Thanks!