pinafore/templates/service-worker.js

117 lines
3.4 KiB
JavaScript

const timestamp = '__timestamp__'
const ASSETS = `assets_${timestamp}`
const WEBPACK_ASSETS = `webpack_assets_${timestamp}`
const ON_DEMAND = `ondemand_${timestamp}`
// `assets` is an array of everything in the `assets` directory
const assets = __assets__
.map(file => file.startsWith('/') ? file : `/${file}`)
.filter(filename => !filename.startsWith('/apple-icon'))
.concat(['/index.html'])
// `shell` is an array of all the files generated by webpack
// also contains '/index.html' for some reason
const webpackAssets = __shell__
.filter(filename => !filename.endsWith('.map'))
.filter(filename => filename !== '/index.html')
// `routes` is an array of `{ pattern: RegExp }` objects that
// match the pages in your app
const routes = __routes__
self.addEventListener('install', event => {
event.waitUntil((async () => {
await Promise.all([
caches.open(WEBPACK_ASSETS).then(cache => cache.addAll(webpackAssets)),
caches.open(ASSETS).then(cache => cache.addAll(assets))
])
self.skipWaiting()
})())
})
self.addEventListener('activate', event => {
event.waitUntil((async () => {
let keys = await caches.keys()
// delete old asset/ondemand caches
for (let key of keys) {
if (key !== ASSETS &&
key !== ON_DEMAND &&
!key.startsWith('webpack_assets_')) {
await caches.delete(key)
}
}
// for webpack assets, keep the two latest builds because we may need
// them when the service worker has installed but the page has not
// yet reloaded (e.g. when it gives the toast saying "please reload"
// but then you don't refresh and instead load an async chunk)
let webpackKeysToDelete = keys
.filter(key => key.startsWith('webpack_assets_'))
.sort((a, b) => {
let aTimestamp = parseInt(a.substring(15), 10)
let bTimestamp = parseInt(b.substring(15), 10)
return bTimestamp < aTimestamp ? -1 : 1
})
.slice(2)
for (let key of webpackKeysToDelete) {
await caches.delete(key)
}
await self.clients.claim()
})())
})
const ON_DEMAND_PATHS = [
'/system/accounts/avatars'
]
self.addEventListener('fetch', event => {
const req = event.request
const url = new URL(req.url)
// don't try to handle e.g. data: URIs
if (!url.protocol.startsWith('http')) {
return
}
event.respondWith((async () => {
let sameOrigin = url.origin === self.origin
if (sameOrigin) {
// always serve webpack-generated resources and
// assets from the cache if possible
let response = await caches.match(req)
if (response) {
return response
}
// for routes, serve the /index.html file from the most recent
// assets cache
if (routes.find(route => route.pattern.test(url.pathname))) {
return caches.match('/index.html')
}
}
// For these GET requests, go cache-first
if (req.method === 'GET' &&
ON_DEMAND_PATHS.some(pattern => url.pathname.startsWith(pattern))) {
let cache = await caches.open(ON_DEMAND)
let response = await cache.match(req)
if (response) {
// update asynchronously
fetch(req).then(response => {
cache.put(req, response.clone())
})
return response
}
response = await fetch(req)
cache.put(req, response.clone())
return response
}
// for everything else, go network-only
return fetch(req)
})())
})