service-worker.published.js

// Caution! Be sure you understand the caveats before publishing an application with
// offline support. See https://aka.ms/blazor-offline-considerations

self.importScripts('./service-worker-assets.js')
self.addEventListener('install', event => {
  event.waitUntil(
    Promise.all([
      onInstall(),
      self.skipWaiting()
    ])
  )
})
self.addEventListener('activate', event => {
  event.waitUntil(
    Promise.all(
      [
        onActivate(),
        self.clients.claim(),
        self.skipWaiting()
      ]
    )
      .catch(
        (err) => { // eslint-disable-line
          event.skipWaiting()
        }
      )
  )
})
self.addEventListener('fetch', event => event.respondWith(onFetch(event)))

const cacheNamePrefix = 'offline-cache-'
const cacheName = `${cacheNamePrefix}${self.assetsManifest.version}`
const offlineAssetsInclude = [/\.dll$/, /\.pdb$/, /\.wasm/, /\.html/, /\.js$/, /\.json$/, /\.css$/, /\.woff$/, /\.png$/, /\.jpe?g$/, /\.gif$/, /\.ico$/, /\.blat$/, /\.dat$/]
const offlineAssetsExclude = [/^service-worker\.js$/]

async function onInstall (event) {
  console.info('Service worker: Install')

  // Fetch and cache all matching items from the assets manifest
  const assetsRequests = self.assetsManifest.assets
    .filter(asset => offlineAssetsInclude.some(pattern => pattern.test(asset.url)))
    .filter(asset => !offlineAssetsExclude.some(pattern => pattern.test(asset.url)))
    .map(asset => new Request(asset.url, { integrity: asset.hash, cache: 'no-cache' }))

  await caches.open(cacheName)
    .then(cache => cache.addAll(assetsRequests))
    .then(() => {
      return self.skipWaiting()
    })
}

async function onActivate (event) {
  console.info('Service worker: Activate')

  // Delete unused caches
  const cacheKeys = await caches.keys()
  await Promise.all(cacheKeys
    .filter(key => key.startsWith(cacheNamePrefix) && key !== cacheName)
    .map(key => caches.delete(key)))
}

async function onFetch (event) {
  let cachedResponse = null
  if (event.request.method === 'GET') {
    // For all navigation requests, try to serve index.html from cache
    // If you need some URLs to be server-rendered, edit the following check to exclude those URLs
    const shouldServeIndexHtml = event.request.mode === 'navigate'

    const request = shouldServeIndexHtml ? 'index.html' : event.request
    const cache = await caches.open(cacheName)
    cachedResponse = await cache.match(request)
  }

  return cachedResponse || fetch(event.request)
}