pinafore/templates/service-worker.js
2018-01-30 22:00:25 -08:00

96 lines
2.4 KiB
JavaScript

const timestamp = '__timestamp__'
const ASSETS = `cache${timestamp}`
// `shell` is an array of all the files generated by webpack,
// `assets` is an array of everything in the `assets` directory
const to_cache = __shell__.concat(__assets__)
const cached = new Set(to_cache)
// `routes` is an array of `{ pattern: RegExp }` objects that
// match the pages in your app
const routes = __routes__
self.addEventListener('install', event => {
event.waitUntil(
caches
.open(ASSETS)
.then(cache => cache.addAll(to_cache))
.then(() => {
self.skipWaiting()
})
)
})
self.addEventListener('activate', event => {
event.waitUntil(
caches.keys().then(async keys => {
// delete old caches
for (const key of keys) {
if (key !== ASSETS) {
await caches.delete(key)
}
}
await self.clients.claim()
})
)
})
const CACHE_FIRST = [
'/system/accounts/avatars'
]
self.addEventListener('fetch', event => {
const req = event.request
const url = new URL(req.url)
// don't try to handle e.g. data: URIs
if (!url.protocol.startsWith('http')) {
return
}
// always serve assets and webpack-generated files from cache
if (cached.has(url.pathname)) {
event.respondWith(caches.match(req))
return
}
// for pages, you might want to serve a shell `index.html` file,
// which Sapper has generated for you. It's not right for every
// app, but if it's right for yours then uncomment this section
if (url.origin === self.origin && routes.find(route => route.pattern.test(url.pathname))) {
event.respondWith(caches.match('/index.html'))
return
}
// For non-GET requests, go network-only
if (req.method !== 'GET') {
event.respondWith(fetch(req))
return
}
// For these, go cache-first.
if (CACHE_FIRST.some(pattern => url.pathname.startsWith(pattern))) {
event.respondWith(caches
.open(`offline${timestamp}`)
.then(async cache => {
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
}))
return
}
// for everything else, go network-only
event.respondWith(fetch(req))
})