hoppscotch/sw.js
liyasthomas 5b90289dd4 PWA
2019-08-22 10:10:40 +05:30

149 lines
6.2 KiB
JavaScript

importScripts('https://storage.googleapis.com/workbox-cdn/releases/4.3.1/workbox-sw.js');
if (workbox) {
console.log(`Yay! Workbox is loaded 🎉`);
} else {
console.log(`Boo! Workbox didn't load 😬`);
}
workbox.routing.registerRoute(
new RegExp('.*\.js'),
new workbox.strategies.NetworkFirst()
);
workbox.routing.registerRoute(
// Cache CSS files.
/\.css$/,
// Use cache but update in the background.
new workbox.strategies.StaleWhileRevalidate({
// Use a custom cache name.
cacheName: 'css-cache',
})
);
workbox.routing.registerRoute(
// Cache image files.
/\.(?:png|jpg|jpeg|svg|gif)$/,
// Use the cache if it's available.
new workbox.strategies.CacheFirst({
// Use a custom cache name.
cacheName: 'image-cache',
plugins: [
new workbox.expiration.Plugin({
// Cache only 20 images.
maxEntries: 20,
// Cache for a maximum of a week.
maxAgeSeconds: 7 * 24 * 60 * 60,
})
],
})
);
workbox.precaching.precacheAndRoute([
'/postwoman/style.css',
'/postwoman/script.js',
{
url: '/postwoman/index.html',
revision: '383676'
},
]);
var CACHE_VERSION = 1;
var CURRENT_CACHES = {
prefetch: 'prefetch-cache-v' + CACHE_VERSION
};
self.addEventListener('install', function (event) {
var now = Date.now();
var urlsToPrefetch = [
'/postwoman/index.html',
];
// All of these logging statements should be visible via the "Inspect" interface
// for the relevant SW accessed via chrome://serviceworker-internals
console.log('Handling install event. Resources to prefetch:', urlsToPrefetch);
event.waitUntil(
caches.open(CURRENT_CACHES.prefetch).then(function (cache) {
var cachePromises = urlsToPrefetch.map(function (urlToPrefetch) {
// This constructs a new URL object using the service worker's script location as the base
// for relative URLs.
var url = new URL(urlToPrefetch, location.href);
// Append a cache-bust=TIMESTAMP URL parameter to each URL's query string.
// This is particularly important when precaching resources that are later used in the
// fetch handler as responses directly, without consulting the network (i.e. cache-first).
// If we were to get back a response from the HTTP browser cache for this precaching request
// then that stale response would be used indefinitely, or at least until the next time
// the service worker script changes triggering the install flow.
url.search += (url.search ? '&' : '?') + 'cache-bust=' + now;
// It's very important to use {mode: 'no-cors'} if there is any chance that
// the resources being fetched are served off of a server that doesn't support
// CORS (http://en.wikipedia.org/wiki/Cross-origin_resource_sharing).
// In this example, www.chromium.org doesn't support CORS, and the fetch()
// would fail if the default mode of 'cors' was used for the fetch() request.
// The drawback of hardcoding {mode: 'no-cors'} is that the response from all
// cross-origin hosts will always be opaque
// (https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cross-origin-resources)
// and it is not possible to determine whether an opaque response represents a success or failure
// (https://github.com/whatwg/fetch/issues/14).
var request = new Request(url, {
mode: 'no-cors'
});
return fetch(request).then(function (response) {
if (response.status >= 400) {
throw new Error('request for ' + urlToPrefetch +
' failed with status ' + response.statusText);
}
// Use the original URL without the cache-busting parameter as the key for cache.put().
return cache.put(urlToPrefetch, response);
}).catch(function (error) {
console.error('Not caching ' + urlToPrefetch + ' due to ' + error);
});
});
return Promise.all(cachePromises).then(function () {
console.log('Pre-fetching complete.');
});
}).catch(function (error) {
console.error('Pre-fetching failed:', error);
})
);
});
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.
console.log('Deleting out of date cache:', cacheName);
return caches.delete(cacheName);
}
})
);
})
);
});
self.addEventListener('fetch', function (event) {
console.log('Handling fetch event for', event.request.url);
event.respondWith(
// caches.match() will look for a cache entry in all of the caches available to the service worker.
// It's an alternative to first opening a specific named cache and then matching on that.
caches.match(event.request).then(function (response) {
if (response) {
console.log('Found response in cache:', response);
return response;
}
console.log('No response found in cache. About to fetch from network...');
// event.request will always have the proper mode set ('cors, 'no-cors', etc.) so we don't
// have to hardcode 'no-cors' like we do when fetch()ing in the install handler.
return fetch(event.request).then(function (response) {
console.log('Response from network is:', response);
return response;
}).catch(function (error) {
// This catch() will handle exceptions thrown from the fetch() operation.
// Note that a HTTP error response (e.g. 404) will NOT trigger an exception.
// It will return a normal response object that has the appropriate error code set.
console.error('Fetching failed:', error);
throw error;
});
})
);
});