Update to JupyterLab 2.0

[jtpio]

Fixes #68.

Migration guide: https://jupyterlab.readthedocs.io/en/latest/developer/extension_migration.html#jupyterlab-1-x-to-2-x-extension-migration-guide

[jtpio]

This builds, but it needs a manual pass to make sure everything behaves as expected.

For example, the Python icon in the launcher card doesn't show anymore:

[jtpio]

This link doesn't work (yet). We should check whether it gets updated once 2.0 final is published.

[jtpio]

Looks like b81943d fixes the icon issue.

A new LabIcon must be created to register a new icon with a name, and then be looked up here when rendered as a React element: https://github.com/jupyterlab/jupyterlab/blob/b66bb79116285ccbd0876a6263ac2c0d6de27c33/packages/ui-components/src/icon/labicon.tsx#L218

[echarles]

Tested this branch and works well with latest jupyterlab master.

[jtpio]

Thanks @echarles for trying it out.

We can check with the latest rc (that includes the icon fix from jupyterlab/jupyterlab#7864), which should make b81943d not necessary anymore.

[echarles]

I have tried with jlab 2.rc2 with and without b81943d

The icons are not displayed. I will experiment a bit and see what is going on here...

[jtpio]

And that's from a clean install (rm yarn.lock node_modules)?

[echarles]

This is the clean I have done before running the tests, but I should do it again as yesterday was a bit messy.

find . -name node_modules | xargs rm -fr {} || true
find . -name lib | xargs rm -fr {} || true
find . -name build | xargs rm -fr {} || true
find . -name yarn.lock | xargs rm {} || true
find . -name yarn-error.log | xargs rm {} || true
find . -name tsconfig.tsbuildinfo | xargs rm {} || true

[jtpio]

Updated to the latest rc.2 packages. But now tslint seems to be giving errors: https://github.com/jtpio/jupyterlab-extension-examples/pull/70/checks?check_run_id=473012537

[jtpio]

@echarles just tried locally in a fresh conda environment, and icons are also missing.

[echarles]

Maybe we should @telamonian expert eyes here?

[jtpio]

Now using the same pattern as in core JupyterLab:

See f0de1f9.

Also quickly tried the "legacy icon as css class" as mentioned in jupyterlab/jupyterlab#7887 (comment), but without success.

[jtpio]

The lint issue mentioned above appears to be related to the latest TypeScript 3.8 version.

Changing it to ~3.7.5 fixes it now, but we should upgrade to 3.8 in a separate PR.

[telamonian]

Also quickly tried the "legacy icon as css class" as mentioned in jupyterlab/jupyterlab#7887 (comment), but without success.

@jtpio Turns out that although iconClass was getting set up correctly on the DOM, there was no longer any CSS styling directives for how to display background images. That's fixed in jupyterlab/jupyterlab#7947

[jtpio]

Thanks @telamonian, will check that out!

[jtpio]

@echarles I think the examples should now work as before, marking it as ready for review.

cc @fcollonval if you also want to have a look.

[jtpio]

We could consolidate the explanations for the LabIcon in a separate change, maybe after it has been added to the migration guide.

[jtpio]

Updated to the 2.0 packages, since 2.0 final was released yesterday.

This should be good to go.

[echarles]

I think not all icons are migrated.

[echarles]

I will branch from this and make a pass on the extension to deal with:

1. Having the menus under one menu - For now, we have plenty of 'Examples' and I would rather see them under a nice Extension examples menu.

2. We rely on console to show the result of the actions, but for the user, an alert would be easier.

[jtpio]

@echarles I think the other examples just don't have any icon set:

https://github.com/jtpio/jupyterlab-extension-examples/blob/2f87d40d2c3ca09ae02a2653b6d11f7dc9935226/basics/signals/src/index.ts#L67-L71

But it would be nice if they had one (even if it's a placeholder).

[jtpio]

I will branch from this and make a pass on the extension to deal with:

1. Having the menus under one menu - For now, we have plenty of 'Examples' and I would rather see them under a nice `Extension examples` menu.

1. We rely on console to show the result of the actions, but for the user, an alert would be easier.

Sounds good 👍

How about merging this one first to make it easier to iterate and follow?

[echarles]

Merged. Thx a lot @jtpio for this great step. I will iterate on master and submit something tomorrow.

[jtpio]

Thanks!