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