'use strict'; // Special offline and fetch interception is restricted to Android only // we have had a large amount of pain supporting this on Firefox / Safari // it is only strongly required on Android, when PWA gets better on iOS // we can unlock it there as well, for Desktop we can consider unlocking it // if we start supporting offline browsing for laptops if (/(android)/i.test(navigator.userAgent)) { // Incrementing CACHE_VERSION will kick off the install event and force previously cached // resources to be cached again. const CACHE_VERSION = 1; const CURRENT_CACHES = { offline: 'offline-v' + CACHE_VERSION }; const OFFLINE_URL = 'offline.html'; const createCacheBustedRequest = function(url) { var headers = new Headers({ 'Discourse-Track-View': '0' }); var request = new Request(url, {cache: 'reload', headers: headers}); // See https://fetch.spec.whatwg.org/#concept-request-mode // This is not yet supported in Chrome as of M48, so we need to explicitly check to see // if the cache: 'reload' option had any effect. if ('cache' in request) { return request; } // If {cache: 'reload'} didn't have any effect, append a cache-busting URL parameter instead. var bustedUrl = new URL(url, self.location.href); bustedUrl.search += (bustedUrl.search ? '&' : '') + 'cachebust=' + Date.now(); return new Request(bustedUrl, {headers: headers}); } self.addEventListener('install', function(event) { event.waitUntil( // We can't use cache.add() here, since we want OFFLINE_URL to be the cache key, but // the actual URL we end up requesting might include a cache-busting parameter. fetch(createCacheBustedRequest(OFFLINE_URL)).then(function(response) { return caches.open(CURRENT_CACHES.offline).then(function(cache) { return cache.put(OFFLINE_URL, response); }); }).then(function(cache) { self.skipWaiting(); }) ); }); self.addEventListener('activate', function(event) { // Delete all caches that aren't named in CURRENT_CACHES. // While there is only one cache in this example, the same logic will handle the case where // there are multiple versioned caches. var expectedCacheNames = Object.keys(CURRENT_CACHES).map(function(key) { return CURRENT_CACHES[key]; }); event.waitUntil( caches.keys().then(function(cacheNames) { return Promise.all( cacheNames.map(function(cacheName) { if (expectedCacheNames.indexOf(cacheName) === -1) { // If this cache name isn't present in the array of "expected" cache names, // then delete it. return caches.delete(cacheName); } }) ); }).then(function() { self.clients.claim() }) ); }); self.addEventListener('fetch', function(event) { // Bypass service workers if this is a url with a token param if(/\?.*token/i.test(event.request.url)) { return; } // We only want to call event.respondWith() if this is a navigation request // for an HTML page. // request.mode of 'navigate' is unfortunately not supported in Chrome // versions older than 49, so we need to include a less precise fallback, // which checks for a GET request with an Accept: text/html header. if (event.request.mode === 'navigate' || (event.request.method === 'GET' && event.request.headers.get('accept').includes('text/html'))) { event.respondWith( fetch(event.request).catch(function(error) { // The catch is only triggered if fetch() throws an exception, which will most likely // happen due to the server being unreachable. // If fetch() returns a valid HTTP response with an response code in the 4xx or 5xx // range, the catch() will NOT be called. If you need custom handling for 4xx or 5xx // errors, see https://github.com/GoogleChrome/samples/tree/gh-pages/service-worker/fallback-response if (!navigator.onLine) { return caches.match(OFFLINE_URL); } else { throw new Error(error); } }) ); } // 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. }); } const idleThresholdTime = 1000 * 10; // 10 seconds var lastAction = -1; function isIdle() { return lastAction + idleThresholdTime < Date.now(); } function showNotification(title, body, icon, badge, tag, baseUrl, url) { var notificationOptions = { body: body, icon: icon, badge: badge, data: { url: url, baseUrl: baseUrl }, tag: tag } return self.registration.showNotification(title, notificationOptions); } self.addEventListener('push', function(event) { var payload = event.data.json(); if(!isIdle() && payload.hide_when_active) { return false; } event.waitUntil( self.registration.getNotifications({ tag: payload.tag }).then(function(notifications) { if (notifications && notifications.length > 0) { notifications.forEach(function(notification) { notification.close(); }); } return showNotification(payload.title, payload.body, payload.icon, payload.badge, payload.tag, payload.base_url, payload.url); }) ); }); self.addEventListener('notificationclick', function(event) { // Android doesn't close the notification when you click on it // See: http://crbug.com/463146 event.notification.close(); var url = event.notification.data.url; var baseUrl = event.notification.data.baseUrl; // This looks to see if the current window is already open and // focuses if it is event.waitUntil( clients.matchAll({ type: "window" }) .then(function(clientList) { var reusedClientWindow = clientList.some(function(client) { if (client.url === baseUrl + url && 'focus' in client) { client.focus(); return true; } if ('postMessage' in client && 'focus' in client) { client.focus(); client.postMessage({ url: url }); return true; } return false; }); if (!reusedClientWindow && clients.openWindow) return clients.openWindow(baseUrl + url); }) ); }); self.addEventListener('message', function(event) { if('lastAction' in event.data){ lastAction = event.data.lastAction; }}); <% DiscoursePluginRegistry.service_workers.each do |js| %> <%=raw "#{File.read(js)}" %> <% end %>