Expose createProxy

[jtpio]

Alternative to #42.

Provide a createProxy from the host package to more conveniently register callbacks that can be invoked from an extension in the IFrame. Users of the host package could technically create the proxy with comlink directly, but since comlink is currently abstracted away it makes sense to keep that way and just expose what is necessary.

Based on Comlink.proxy used for callbacks: https://github.com/GoogleChromeLabs/comlink?tab=readme-ov-file#callbacks

Fixes #9

Changes

• Expose createProxy from jupyter-iframe-commands-host
• Document usage

Example

Host

import { createBridge, createProxy } from 'jupyter-iframe-commands-host';

const commandBridge = createBridge({ iframeId: 'jupyterlab' });

const kernelStatus = async ({ displayName, isBusy }) => {
  console.log('Received kernel status update from the iframe');
  console.log('Display Name:', displayName);
  console.log('Is Busy:', isBusy);
};

await commandBridge.execute('kernel-status', createProxy({ kernelStatus }));

Custom extension

const demoPlugin: JupyterFrontEndPlugin<void> = {
  id: 'jupyter-iframe-commands:demo-callback',
  autoStart: true,
  description: 'A demo plugin to show how to use the jupyter-iframe-commands.',
  requires: [ILabStatus, INotebookTracker],
  activate: async (
    app: JupyterFrontEnd,
    labStatus: ILabStatus,
    tracker: INotebookTracker
  ) => {
    const { commands } = app;

    commands.addCommand('kernel-status', {
      label: 'Kernel Status',
      execute: args => {
        console.log('Kernel status command executed with args:', args);

        const kernelStatus = args['kernelStatus'] as unknown as (
          args?: any
        ) => void;

        labStatus.busySignal.connect(async () => {
          const kernelSpec =
            await tracker.currentWidget?.sessionContext?.session?.kernel?.spec;
          const displayName = kernelSpec
            ? kernelSpec.display_name
            : 'Loading...';
          kernelStatus({ displayName, isBusy: labStatus.isBusy });
        });
      }
    });
  }
};

When testing the above snippets with the demo:

jupyter-iframe-commands.mp4

[gjmooney]

Thanks!