HugoサイトのPWA対応

{
    "theme_color": "#a4115e",
    "background_color": "#f2f4f4",
    "display": "standalone",
    "scope": "https://raizin.net/",
    "start_url": "https://raizin.net/",
    "name": "RAIZIN INC.",
    "short_name": "RAIZIN",
    "description": "\u6587\u66f8\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\uff08DMS\uff09Document Management System",
    "icons": [
        {
            "src": "/images/manifest/icon-192x192.png",
            "sizes": "192x192",
            "type": "image/png"
        },
        {
            "src": "/images/manifest/icon-256x256.png",
            "sizes": "256x256",
            "type": "image/png"
        },
        {
            "src": "/images/manifest/icon-384x384.png",
            "sizes": "384x384",
            "type": "image/png"
        },
        {
            "src": "/images/manifest/icon-512x512.png",
            "sizes": "512x512",
            "type": "image/png"
        }
    ]
}

// Incrementing OFFLINE_VERSION will kick off the install event and force
// previously cached resources to be updated from the network.
const OFFLINE_VERSION = 1;
const CACHE_NAME = 'offline';
// Customize this with a different URL if needed.
const OFFLINE_URL = 'offline.html';

self.addEventListener('install', (event) => {
  event.waitUntil((async () => {
    const cache = await caches.open(CACHE_NAME);
    // Setting {cache: 'reload'} in the new request will ensure that the response
    // isn't fulfilled from the HTTP cache; i.e., it will be from the network.
    await cache.add(new Request(OFFLINE_URL, {cache: 'reload'}));
  })());
});

self.addEventListener('activate', (event) => {
  event.waitUntil((async () => {
    // Enable navigation preload if it's supported.
    // See https://developers.google.com/web/updates/2017/02/navigation-preload
    if ('navigationPreload' in self.registration) {
      await self.registration.navigationPreload.enable();
    }
  })());

  // Tell the active service worker to take control of the page immediately.
  self.clients.claim();
});

self.addEventListener('fetch', (event) => {
  // We only want to call event.respondWith() if this is a navigation request
  // for an HTML page.
  if (event.request.mode === 'navigate') {
    event.respondWith((async () => {
      try {
        // First, try to use the navigation preload response if it's supported.
        const preloadResponse = await event.preloadResponse;
        if (preloadResponse) {
          return preloadResponse;
        }

        const networkResponse = await fetch(event.request);
        return networkResponse;
      } catch (error) {
        // catch is only triggered if an exception is thrown, which is likely
        // due to a network error.
        // If fetch() returns a valid HTTP response with a response code in
        // the 4xx or 5xx range, the catch() will NOT be called.
        console.log('Fetch failed; returning offline page instead.', error);

        const cache = await caches.open(CACHE_NAME);
        const cachedResponse = await cache.match(OFFLINE_URL);
        return cachedResponse;
      }
    })());
  }

  // If our if() condition is false, then this fetch handler won't intercept the
  // request. If there are any other fetch handlers registered, they will get a
  // chance to call event.respondWith(). If no fetch handlers call
  // event.respondWith(), the request will be handled by the browser as if there
  // were no service worker involvement.
});

<script>
navigator.serviceWorker.register('/generate-sw.js');
</script>