JavaScript Internals (521 Qs)•Part 3: DOM, Event Flow, Timers & Browser APIs (104 - 173)
What is an app shell model
An application shell (or app shell) architecture is one way to build a Progressive Web App that reliably and instantly loads on your users' screens, similar to what you see in native applications. It is useful for getting some initial HTML to the screen fast without a network.
Practical Code Example
javascript
// App Shell Architecture separates the static UI container from dynamic data:
// 1. Cache App Shell (Header, Nav, CSS) immediately on install:
caches.open('app-shell-v1').then(cache => {
return cache.addAll(['/', '/index.html', '/shell.css', '/shell.js']);
});
// 2. Render Shell instantly on navigation, then fetch dynamic content via API.