jupyterlab/dev_mode/bootstrap.js

/*-----------------------------------------------------------------------------
| Copyright (c) Jupyter Development Team.
| Distributed under the terms of the Modified BSD License.
|----------------------------------------------------------------------------*/

// We copy some of the pageconfig parsing logic in @jupyterlab/coreutils
// below, since this must run before any other files are loaded (including
// @jupyterlab/coreutils).

/**
 * Get global configuration data for the Jupyter application.
 *
 * @param name - The name of the configuration option.
 *
 * @returns The config value or an empty string if not found.
 *
 * #### Notes
 * All values are treated as strings. For browser based applications, it is
 * assumed that the page HTML includes a script tag with the id
 * `jupyter-config-data` containing the configuration as valid JSON.
 */
let _CONFIG_DATA = null;
function getOption(name) {
  if (_CONFIG_DATA === null) {
    let configData = {};
    // Use script tag if available.
    if (typeof document !== 'undefined' && document) {
      const el = document.getElementById('jupyter-config-data');

      if (el) {
        configData = JSON.parse(el.textContent || '{}');
      }
    }
    _CONFIG_DATA = configData;
  }

  return _CONFIG_DATA[name] || '';
}

// eslint-disable-next-line no-undef
__webpack_public_path__ = getOption('fullStaticUrl') + '/';

// Promise.allSettled polyfill, until our supported browsers implement it
// See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled
if (Promise.allSettled === undefined) {
  Promise.allSettled = promises =>
    Promise.all(
      promises.map(promise =>
        promise.then(
          value => ({
            status: 'fulfilled',
            value
          }),
          reason => ({
            status: 'rejected',
            reason
          })
        )
      )
    );
}

function loadScript(url) {
  return new Promise((resolve, reject) => {
    const newScript = document.createElement('script');
    newScript.onerror = reject;
    newScript.onload = resolve;
    newScript.async = true;
    document.head.appendChild(newScript);
    newScript.src = url;
  });
}

async function loadComponent(url, scope) {
  await loadScript(url);

  // From https://webpack.js.org/concepts/module-federation/#dynamic-remote-containers
  // eslint-disable-next-line no-undef
  await __webpack_init_sharing__('default');
  const container = window._JUPYTERLAB[scope];
  // Initialize the container, it may provide shared modules and may need ours
  // eslint-disable-next-line no-undef
  await container.init(__webpack_share_scopes__.default);
}

void (async function bootstrap() {
  // This is all the data needed to load and activate plugins. This should be
  // gathered by the server and put onto the initial page template.
  const extension_data = getOption('federated_extensions');

  // We first load all federated components so that the shared module
  // deduplication can run and figure out which shared modules from all
  // components should be actually used. We have to do this before importing
  // and using the module that actually uses these components so that all
  // dependencies are initialized.
  let labExtensionUrl = getOption('fullLabextensionsUrl');
  const extensions = await Promise.allSettled(
    extension_data.map(async data => {
      await loadComponent(
        `${labExtensionUrl}/${data.name}/${data.load}`,
        data.name
      );
    })
  );

  extensions.forEach(p => {
    if (p.status === 'rejected') {
      // There was an error loading the component
      console.error(p.reason);
    }
  });

  // Now that all federated containers are initialized with the main
  // container, we can import the main function.
  let main = (await import('./index.out.js')).main;
  window.addEventListener('load', main);
})();