sw.js

/*globals self, caches, fetch, console */
import { MusicDB } from "./musicdb.js";
import { DatabaseLoadingMessages } from "./actions.js";
import {
  APP_CACHE_NAME,
  IMAGES_CACHE_NAME,
  FLAC_WORKER_CACHE_NAME,
  urlsToCache
} from "./swConstants.js";

self.addEventListener("activate", event => {
  var cacheWhitelist = [
    APP_CACHE_NAME,
    IMAGES_CACHE_NAME,
    FLAC_WORKER_CACHE_NAME
  ];
  event.waitUntil(
    Promise.all([
      event.waitUntil(self.clients.claim()),
      caches.keys().then(cacheNames => {
        return Promise.all(
          cacheNames.map(cacheName => {
            if (cacheWhitelist.indexOf(cacheName) === -1) {
              return caches.delete(cacheName);
            }
          })
        );
      })
    ])
  );
});

self.addEventListener("install", event => {
  const cachesPromises = [];
  self.skipWaiting();
  Object.entries(urlsToCache).forEach(([cacheName, urls]) => {
    cachesPromises.push(
      event.waitUntil(
        caches.open(cacheName).then(cache => {
          return cache.addAll(urls);
        })
      )
    );
  });
  return Promise.all(cachesPromises);
});

self.addEventListener("fetch", event => {
  event.respondWith(
    caches.match(event.request).then(response => {
      if (response) {
        // console.log("SW: fetch serving from cache", event, response);
        return response;
      }
      if (/\/art$/.test(event.request.url)) {
        return fetch(event.request).then(response => {
          if (!response.ok) {
            return response;
          }
          return caches.open(IMAGES_CACHE_NAME).then(cache => {
            cache.put(event.request, response.clone());
            return response;
          });
        });
      }
      // console.log("SW: fetch cache miss, forwarding", event);
      return fetch(event.request);
    })
  );
});