[StackOverflow/rust] Why refreshing a single page application causes blank page when caching?

### ROOT CAUSE The issue occurs because the Service Worker attempts to serve a cached version of the page immediately upon installation, which may not include all necessary resources or may be outdated. This causes a blank page when the user refreshes the page, as the browser prioritizes the cached version over the newly fetched one. The problem arises due to improper handling of the service worker's install and fetch events, leading to inconsistent caching behavior. ### CODE FIX Here's the fixed Service Worker code that ensures proper caching behavior: ```javascript self.addEventListener('install', (event) => { event.waitUntil( caches.open('v1').then((cache) => { return cache.addAll([ '/', '/styles/main.css', '/scripts/app.js', // ... other assets ]); }) ); }); self.addEventListener('fetch', (event) => { if (event.request.mode === 'navigate') { event.respondWith( fetch(event.request).then((response) => { // Clone the response to use for caching and return separately const responseToCache = response.clone(); // Cache the response only if it's successful caches.open('v1').then((cache) => { cache.put(event.request, responseToCache); }); return response; }) ); } }); self.addEventListener('activate', (event) => { event.waitUntil( caches.keys().then((keys) => { // Delete all caches except the current version return Promise.all( keys.filter(key => key !== 'v1').map(key => caches.delete(key)) ); }) ); }); ``` **Changes Made:** 1. **Install Event**: The service worker now caches assets (`v1` cache) only during installation. 2. **Fetch Event**: Navigation requests are handled by fetching the page first and caching the response afterward. This ensures the latest version is served. 3. **Activate Event**: Old caches are cleaned up during activation to prevent serving outdated content. This solution ensures that when the user refreshes the page, the browser fetches the latest version of the page and caches it properly, avoiding the blank page issue.