|
| 1 | +var cdn = { |
| 2 | + max: 'https://maxcdn.bootstrapcdn.com' |
| 3 | +} |
| 4 | + |
| 5 | +var vendor = { |
| 6 | + fontAwesome: 'https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3' |
| 7 | +}; |
| 8 | + |
| 9 | +var URLS = { |
| 10 | + app: [ |
| 11 | + 'icons/launcher-icon-0-75x.png', |
| 12 | + 'icons/launcher-icon-1-5x.png', |
| 13 | + 'icons/launcher-icon-1x.png', |
| 14 | + 'icons/launcher-icon-2x.png', |
| 15 | + 'icons/launcher-icon-3x.png', |
| 16 | + 'icons/launcher-icon-4x.png', |
| 17 | + 'icons/icon-32.png', |
| 18 | + 'index.html', |
| 19 | + 'manifest.json' |
| 20 | + ], |
| 21 | + vendor: [ |
| 22 | + `${vendor.fontAwesome}/css/font-awesome.min.css`, |
| 23 | + `${vendor.fontAwesome}/fonts/fontawesome-webfont.woff2`, // browsers that support sw support woff2 |
| 24 | + ] |
| 25 | +} |
| 26 | + |
| 27 | +var CACHE_NAMES = { |
| 28 | + app: 'noteself-cache-v7', |
| 29 | + vendor: 'vendor-cache-v7' |
| 30 | +}; |
| 31 | + |
| 32 | +function isVendor(url) { |
| 33 | + return url.startsWith(cdn.max); |
| 34 | +} |
| 35 | + |
| 36 | +function cacheAll(cacheName, urls) { |
| 37 | + return caches.open(cacheName).then((cache) => cache.addAll(urls)); |
| 38 | +} |
| 39 | + |
| 40 | +function addToCache(cacheName, request, response) { |
| 41 | + if (response.ok) { |
| 42 | + var clone = response.clone() |
| 43 | + caches.open(cacheName).then((cache) => cache.put(request, clone)); |
| 44 | + } |
| 45 | + return response; |
| 46 | +} |
| 47 | + |
| 48 | +function lookupCache(request) { |
| 49 | + return caches.match(request).then(function(cachedResponse) { |
| 50 | + if (!cachedResponse) { |
| 51 | + throw Error(`${request.url} not found in cache`); |
| 52 | + } |
| 53 | + return cachedResponse; |
| 54 | + }); |
| 55 | +} |
| 56 | + |
| 57 | +function fetchThenCache(request, cacheName) { |
| 58 | + var fetchRequest = fetch(request); |
| 59 | + // add to cache, but don't block resolve of this promise on caching |
| 60 | + fetchRequest.then((response) => addToCache(cacheName, request, response)); |
| 61 | + return fetchRequest; |
| 62 | +} |
| 63 | + |
| 64 | +function raceRequest(request, cacheName) { |
| 65 | + var attempts = [ |
| 66 | + fetchThenCache(request, cacheName), |
| 67 | + lookupCache(request) |
| 68 | + ]; |
| 69 | + return new Promise(function(resolve, reject) { |
| 70 | + // resolve this promise once one resolves |
| 71 | + attempts.forEach((attempt) => attempt.then(resolve)); |
| 72 | + // reject if all promises reject |
| 73 | + attempts.reduce((verdict, attempt) => verdict.catch(() => attempt)) |
| 74 | + .catch(() => reject(Error('Unable to resolve request from network or cache.'))); |
| 75 | + }) |
| 76 | +} |
| 77 | + |
| 78 | +function cleanupCache() { |
| 79 | + var validKeys = Object.keys(CACHE_NAMES).map((key) => CACHE_NAMES[key]); |
| 80 | + return caches.keys().then((localKeys) => Promise.all( |
| 81 | + localKeys.map((key) => { |
| 82 | + if (validKeys.indexOf(key) === -1) { // key no longer in our list |
| 83 | + return caches.delete(key); |
| 84 | + } |
| 85 | + }) |
| 86 | + )); |
| 87 | +} |
| 88 | + |
| 89 | +self.addEventListener('install', function(evt) { |
| 90 | + var cachingCompleted = Promise.all([ |
| 91 | + cacheAll(CACHE_NAMES.app, URLS.app), |
| 92 | + //cacheAll(CACHE_NAMES.vendor, URLS.vendor) |
| 93 | + ]).then(() => self.skipWaiting()) |
| 94 | + |
| 95 | + evt.waitUntil(cachingCompleted); |
| 96 | +}); |
| 97 | + |
| 98 | +self.addEventListener('activate', function(evt) { |
| 99 | + evt.waitUntil(Promise.all([ |
| 100 | + cleanupCache(), |
| 101 | + self.clients.claim() // claim immediately so the page can be controlled by the sw immediately |
| 102 | + ])); |
| 103 | +}); |
| 104 | + |
| 105 | +self.addEventListener('fetch', function(evt) { |
| 106 | + var request = evt.request; |
| 107 | + var response; |
| 108 | + |
| 109 | + // only handle GET requests |
| 110 | + if (request.method !== 'GET') return; |
| 111 | + |
| 112 | + if (isVendor(request.url)) { |
| 113 | + // vendor requests: check cache first, fallback to fetch |
| 114 | + response = lookupCache(request) |
| 115 | + .catch(() => fetchThenCache(request, CACHE_NAMES.vendor)); |
| 116 | + } else { |
| 117 | + // app request: race cache/fetch (bonus: update in background) |
| 118 | + response = raceRequest(request, CACHE_NAMES.app); |
| 119 | + } |
| 120 | + evt.respondWith(response); |
| 121 | +}); |
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