## Where communities thrive

• Join over 1.5M+ people
• Join over 100K+ communities
• Free without limits
• Create your own community
##### Activity
Steven Silvester
@blink1073
Jason Grout
@jasongrout
@Sakthi - are you on jlab 2.0?
Using jlab 2.0, a kernel change involves disposing the kernel connection and starting a new kernel connection, so you'll need to listen at a higher level than the kernel. For example, if you are using the session context, you can listen to the kernelChanged signal.
Adam Thornton
@athornton
Ultimately, how do Jupyterlab page_config settings get loaded? I'm trying to move to JL 2.x. I am running under K8s. I have a custom service set up inside my K8s cluster to provide access to the Hub API. Under JL 1.x I could set JUPYTERHUB_API_URL and Lab could talk to hub, but I was using jupyter-labhub. I understand that in 2.x Hub support has been folded into core JL, but it doesn't seem that the Lab is ever establishing contact with the Hub and saying "hey, I'm ready for you."
I am presuming this is getting loaded via a jupyter config setting, but I am not having any luck finding the appropriate one.
Philipp Rudiger
@philippjfr
If I want to override an internal component, in this case the Launcher. How do I prevent the original component from activating and generating errors like this:
Plugin '@jupyterlab/launcher-extension:plugin' failed to activate.

Error: Command 'launcher:create' already registered.
at CommandRegistry.push.lBOR.CommandRegistry.addCommand (index.js:123)
at activate (index.js:36)
at index.js:156
at async Promise.all (:8889/index 60)
Jason Grout
@jasongrout
jupyter labextension disable ...
disable the built-in extension
Philipp Rudiger
@philippjfr
Thanks @jasongrout !
Gordon Bai
@GdBai
I have a question about theme: After I installed a theme extension, the newly installed theme won't appear in the Settings -> JupyterLab Theme submenu. How can I fix this?
Tingkai Liu
@TK-21st
Is there a convenience function to parse and display traceback(in ANSI code) from KernelReplyMsg for display in custom widget? The only ansi parse I could find was in rendermime/src/renderer, which has a function called Private.ansiSpan but it's not exported...
Can't quite find how OutputArea renders it unfortunately.
Tim Paine
@timkpaine
@telamonian this example is looking good :eyes: jpmorganchase/regular-table#4
Gordon Bai
@GdBai

I have a question about theme: After I installed a theme extension, the newly installed theme won't appear in the Settings -> JupyterLab Theme submenu. How can I fix this?

Well it turned out to be a problem described in this issue jupyterlab/jupyterlab#8122 . I deleted build_config.json and everything works fine!

Afshin Taylor Darian
@afshin
@GdBai Glad you found an answer to your issue!
Tim Paine
@timkpaine
is there a good strategy for turning off a lumino dependency in the classic notebook? I just get utils.js:62 Failed to load extension: Array(1)0: "@lumino/widgets"length: 1__proto__: Array(0) Error: Script error for "@lumino/widgets" trying to naively hook it in
Tim Paine
@timkpaine
I suppose I can just bundle in lumino, since we won't have the same issue with multiple lumino version on the page that we have in jlab?
Max Klein
@telamonian
@timkpaine I think we're going to need some more details
Yuvi Panda
@yuvipanda
are there any code samples on how to use react inside jupyterlab?
to go back, all I'm trying to do is to have a dropdown + another component inside a component
I know how to do this with plain DOM, or with react
trying to find out how I would with JupyterLab
Yuvi Panda
@yuvipanda
@jtpio Looks like exactly what I needed! Thank you
Jeremy Tuloup
@jtpio
do you think this should be made more visible in the docs? for now there is a link to the repo on the latest version of this page: https://jupyterlab.readthedocs.io/en/latest/developer/extension_dev.html
Yuvi Panda
@yuvipanda
@jtpio I think it should be in https://jupyterlab.readthedocs.io/en/latest/developer/virtualdom.html. Also, I see there's a bunch of 'literalinclude' with code snippets that aren't present in the rendered output
IMO that would've been of big help
@jtpio works on my local build but not on RTD, latest or stable
Jeremy Tuloup
@jtpio
do you have a screenshot of what it looks like locally?
Yuvi Panda
@yuvipanda
@jtpio I pasted in the issue
Jeremy Tuloup
@jtpio
:thumbsup:
Yuvi Panda
@yuvipanda
@jtpio actually to step back - all I wanna do is to have a dropdown above another Lumino component as the children of my widget. I can't figure out at all how to do that with Lumino. Can you help / have pointers?
This feels like it should be fairly simple but I've not found anything at all in the docs
Jeremy Tuloup
@jtpio
with the child Lumino component updating when the value of the dropdown changes?
Yuvi Panda
@yuvipanda
@jtpio yeah, some code needs to be triggered
actually I think I can just take lumino out of the equation completely and go pure react
there isn't really any lumino need there
Jeremy Tuloup
@jtpio
Yuvi Panda
@yuvipanda
oooh nice, I didn't know that was react now!
I like it
Jeremy Tuloup
@jtpio
yes there is a bit of react in some places in core
Naveen Michaud-Agrawal
@nmichaud
@jtpio any thoughts on moving the ReactWidget into lumino proper? Seems it would be useful outside of jupyterlab
also looks like it doesn't depend on anything within JupyterLab itself
Jeremy Tuloup
@jtpio
@nmichaud maybe worth asking on the lumino channel or in a new issue?
otherwise it should be possible to import from apputils in standalone applications outside of jupyterlab with import { ReactWidget } from '@jupyterlab/apputils';
Yuvi Panda
@yuvipanda
how do I set the min-width of my sidebar? css doesn't seem to work because width setup is in JS?
Yuvi Panda
@yuvipanda
also just wanted to say y'all are pretty awesome. I know I can be very cranky and unappreciative sometimes, acting as an entitled user. I'm sorry, and <3
Steven Silvester
@blink1073
Hi Yuvi, we're all cranky these days. 😀. I think what you're seeing is CSS specificity, the width is set on the sidebar id. You can add the property with the !important modifier or use a more specific rule