react-universally/client/registerServiceWorker.js

A starter kit for universal react applications.

/**
 * We use the offline-plugin to generate a service worker.  See the webpack
 * config for more details.
 *
 * We need to ensure that the runtime is installed so that the generated
 * service worker is executed.
 *
 * NOTE: We only enable the service worker for non-development environments.
 */

import config from '../config';

if (process.env.BUILD_FLAG_IS_DEV === 'false') {
  // We check the shared config, ensuring that the service worker has been
  // enabled.
  if (config('serviceWorker.enabled')) {
    // eslint-disable-next-line global-require
    const OfflinePluginRuntime = require('offline-plugin/runtime');

    // Install the offline plugin, which instantiates our service worker and app
    // cache to support precaching of assets and offline support.
    OfflinePluginRuntime.install({
      onUpdating: () => undefined,
      // When an update is ready we will tell the new SW to take control immediately.
      onUpdateReady: () => OfflinePluginRuntime.applyUpdate(),
      // After the new SW update has been applied we will reload the users page
      // to ensure they are using the latest assets.
      // This only gets run if there were updates available for our cached assets.
      onUpdated: () => window.location.reload(),
      onUpdateFailed: () => undefined,
    });
  }
}