Follow-up on #846

[trungleduc]

Reposted from #846

• Depend on https://github.com/jupyter-server/jupyter_server_mathjax (Switch to a lab-based app for the Voila frontend #846 (review))
• Load JupyterLab extensions from the CDN? Requires upstream feature for dynamic extensions?
• Support JupyterLab themes, as an alternative or in addition to the theme and light themes from nbconvert: https://github.com/jupyter/nbconvert/blob/957c2e2476e1106fd4976af7d104c01cd5bb7562/setup.py#L52-L56
• Fix the initial kernels / sessions request by providing mock managers: Switch to a lab-based app for the Voila frontend #846 (review)

[jtpio]

We should also consider updating to the latest @jupyterlab packages and leverage the changes to ServiceManager as discussed in #846 (review).

Updating the top post to add this item.

[bollwyvl]

Load JupyterLab extensions from the CDN?

Please, whatever happens, make CDN opt-in, providing a robust way to serve a known list of locally-available extensions, so that a they can be deployed along with a voila deployment. Reliance on (or having to co-deploy) a CDN is the cause of many issues when trying to actually own a non-public jupyter stack, and the well-understood scope and directory layout of prebuilt labextensions makes it far easier to manage than the previous requirejs mess.

To account for versioning, it might even be possible to serve directly from a pile of not-installed .whl or .tar.bz2 packages, as the precise location of the assets would be known in advance. I'm not sure how notebooks would advertise these versions, but this seems like an important, higher-order concern, and maybe not something voila can solve unilaterally.

Support JupyterLab themes

Yes. Encouraging folk to author in a theme environment consistent with their deployment is huge.

[martinRenou]

Support JupyterLab themes

Yes. Encouraging folk to author in a theme environment consistent with their deployment is huge.

Just adding a note that jupyterlab themes are actually already supported :D Though we don't support yet dynamically switching themes in the front-end.

[bollwyvl]

dynamically switching themes in the front-end.

That's probably good for most deployment use cases.

[trungleduc]

Closing as Load JupyterLab extensions from the CDN? Requires upstream feature for dynamic extensions? is not feasible in 0.5.0