Pre-built Extension Not Working

[rmorshea]

At the moment, when running in a Jupyter Notebook I get the following errors after running each cell:

from panel import extension
extension()

In Jupyter Notebook

VM600:131 Uncaught TypeError: Cannot read properties of undefined (reading 'set_log_level')
    at inline_js (eval at append_javascript (outputarea.js:765), :131:13)
    at run_inline_js (eval at append_javascript (outputarea.js:765), :9053:22)
    at eval (eval at append_javascript (outputarea.js:765), :9068:7)
    at eval (eval at append_javascript (outputarea.js:765), :23:11)
    at Array.forEach ()
    at run_callbacks (eval at append_javascript (outputarea.js:765), :21:36)
    at HTMLLinkElement.on_load (eval at append_javascript (outputarea.js:765), :51:9)

In Jupyter Lab

This doesn't result in an error. Instead Bokeh logs:
[bokeh] setting log level to: 'info'
Upon opening the page though there's a 404 when trying to load a Jupyter Lab extension:

This seems like something's going wrong when setting up Panel. Maybe that's causing the error below?

import idom
from idom_bokeh import IDOM

@idom.component
def Demo():
    return idom.html.h1("hello")

IDOM(Demo)

In Jupyter Notebook

bokeh-2.4.2.min.js:166 Uncaught Error: Model 'IDOM' does not exist. This could be due to a widget or a custom model not being registered before first usage.
    at _.get (bokeh-2.4.2.min.js:166)
    at Function._instantiate_object (bokeh-2.4.2.min.js:165)
    at Function._instantiate_references_json (bokeh-2.4.2.min.js:165)
    at Function.from_json (bokeh-2.4.2.min.js:165)
    at Object.t.embed_items_notebook (bokeh-2.4.2.min.js:591)
    at embed_document (:5:22)
    at :8:5
    at :24:3
    at eval (eval at append_javascript (outputarea.js:765), :138:28)
    at Array.forEach ()

In Jupyter Lab

Same as for the Notebook

The latter error is odd because I'm calling register_models([IDOMView]). Maybe it's getting registered under the wrong name? Even that seems unlikely though, because in the JS bundle generated by bokeh build I can see some "IDOM" string literals.

[hoxbro]

For the jupyter lab 404 you should be able to get it work by running jupyter serverextension enable panel.io.jupyter_server_extension. An issue is created here holoviz/panel#3051 to make this command redundant.