service_worker.js.in

// SPDX-FileCopyrightText: Copyright 2022-2024 EDF (Électricité de France S.A.)
// SPDX-License-Identifier: BSD-3-Clause
// See README for all details on copyright, authorship and license.
//
// Originally based on Mozilla's PWA examples from
// https://github.com/mdn/pwa-examples/, published under CC0

// Populated by the build process, this ensures there is variation on the
// service worker file, so updates get eventually detected (although they might
// need a manual refresh, or even a double refresh)
const CACHE_NAME = "coap-ace-poc-webapp-cache-BUILDID";

const APP_STATIC_RESOURCES = [
  './',
  './manifest.json',
  './coap-ace-poc-webapp.js',
  './coap-ace-poc-webapp_bg.wasm',
  './icon.svg',
  './style.css',
];

self.addEventListener('install', function(e) {
  // Those are cached in here; let's not get browser cache in the way.
  //
  // In a production environment it may be more suitable to serve files
  // from different paths or to serve them with cache-control:
  // must-revalidate (both would enable on-path proxies), but here we want
  // things to update fast for development.
  const headers = new Headers();
  headers.set("Cache-Control", "max-age=0");

  e.waitUntil(
    caches.open(CACHE_NAME).then((cache) =>
      cache.addAll(APP_STATIC_RESOURCES.map((f) => new Request(f, {"headers": headers})))
  ));

  // The new service worker can already pass on all the requests (effectively
  // that's what it does anyway); by the time it is done here, all files in the
  // manifest were already loaded by the application, and will only be accessed
  // again on a reload anyway.
  self.skipWaiting();
});

// delete old caches on activate
self.addEventListener("activate", (event) => {
  event.waitUntil(
    (async () => {
      const names = await caches.keys();
      await Promise.all(
        names.map((name) => {
          if (name !== CACHE_NAME) {
            return caches.delete(name);
          }
        })
      );
      await clients.claim();
    })()
  );
});

self.addEventListener('fetch', (e) => {
  e.respondWith(
    caches.match(e.request)
      // It'd be tempting to leave that out, but if something at installation
      // failed and the scripts are not accessible through the service worker, at least they can be fetched now.
      //
      // Moreover, at least during testing on localhost, this also handles
      // requests that are made to the OAuth server and the AS.
      .then(function (response) { if (response) { return response } else { return fetch(e.request); }})
  );
});