serviceworker.js

'use strict';

// Update cache names any time any of the cached files change.
const CACHE_NAME = 'static-cache-v1';

// Add list of files to cache here.
const FILES_TO_CACHE = [
  'offline.html',
];

self.addEventListener('install', (evt) => {
  // console.log('[ServiceWorker] Install');
  evt.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      // console.log('[ServiceWorker] Pre-caching offline page');
      return cache.addAll(FILES_TO_CACHE);
    })
  );
  self.skipWaiting();
});

self.addEventListener('activate', (evt) => {
  // console.log('[ServiceWorker] Activate');
  // Remove previous cached data from disk.
  evt.waitUntil(
    caches.keys().then((keyList) => {
      return Promise.all(keyList.map((key) => {
        if (key !== CACHE_NAME) {
          // console.log('[ServiceWorker] Removing old cache', key);
          return caches.delete(key);
        }
      }));
    })
  );
  self.clients.claim();
});

self.addEventListener('fetch', (evt) => {
  // console.log('[ServiceWorker] Fetch', evt.request.url);
  // Add fetch event handler here.
  if (evt.request.url.startsWith('https://geoserveis.icgc.cat/servei/catalunya')) {
    evt.respondWith(
      caches.open(CACHE_NAME).then((cache) => {
        return cache.match(evt.request).then((response) => {
          if (response) {
            return response;
          }
          return fetch(evt.request).then((networkResponse) => {
            cache.put(evt.request, networkResponse.clone());
            return networkResponse;
          });
        });
      })
    );
    return;
  }

  if (evt.request.mode !== 'navigate') {
    // Not a page navigation, bail.
    return;
  }

  evt.respondWith(
    fetch(evt.request).catch(() => {
      return caches.open(CACHE_NAME)
        .then((cache) => {
          return cache.match('offline.html');
        });
    })
  );
});