118e5edd24
Summary: Always use the server Reviewed By: antonk52 Differential Revision: D49952286 fbshipit-source-id: 52d2141d5c082e11dfd991534c8213886f526c6a
63 lines
2.3 KiB
JavaScript
63 lines
2.3 KiB
JavaScript
/**
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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// OFFLINE_VERSION is used as an update marker so that on subsequent installations
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// the newer version of the file gets updated.
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// eslint-disable-next-line header/header, no-unused-vars
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const OFFLINE_VERSION = 1.1;
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const CACHE_NAME = 'offline';
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const OFFLINE_URL = 'offline.html';
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self.addEventListener('install', (event) => {
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console.log('Flipper service worker installed');
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event.waitUntil((async () => {
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const cache = await caches.open(CACHE_NAME);
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// Setting {cache: 'reload'} in the new request will ensure that the response
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// isn't fulfilled from the HTTP cache; i.e., it will be from the network.
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await cache.add(new Request(OFFLINE_URL, {cache: 'reload'}));
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})());
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// Force the waiting service worker to become the active service worker.
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self.skipWaiting();
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});
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self.addEventListener('activate', (event) => {
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console.log('Flipper service worker activate');
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event.waitUntil((async () => {
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// Enable navigation preload if it's supported.
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// See https://developers.google.com/web/updates/2017/02/navigation-preload
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if ('navigationPreload' in self.registration) {
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await self.registration.navigationPreload.enable();
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}
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})());
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// Tell the active service worker to take control of the page immediately.
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self.clients.claim();
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});
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self.addEventListener('fetch', (event) => {
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// We only want to call event.respondWith() if this is a navigation request
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// for an HTML page.
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if (event.request.mode === 'navigate') {
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event.respondWith((async () => {
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try {
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// Always try the network first (try flipper server)
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return await fetch(event.request);
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} catch (error) {
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// Catch is only triggered if an exception is thrown, which is likely
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// due to a network error.
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// If fetch() returns a valid HTTP response with a response code in
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// the 4xx or 5xx range, the catch() will NOT be called.
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console.log('Fetch failed; returning offline page instead.', error);
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const cache = await caches.open(CACHE_NAME);
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return await cache.match(OFFLINE_URL);
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}
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})());
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}
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});
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