Service worker preloading images and pages.

static/main.js

@@ -1,3 +1,15 @@
+const registerServiceWorker = async () => {
+    if ('serviceWorker' in navigator) {
+        try {
+            await navigator.serviceWorker.register('/serviceWorker.js', { scope: '/' })
+        } catch (error) {
+            console.error(`Service worker registration failed: ${error}`)
+        }
+    }
+}
+
+registerServiceWorker()
+
 window.addEventListener('load', () => {
     const navBars = document.getElementById('nav-bars')
     const navItems = document.getElementById('nav-items')

static/serviceWorker.js

@@ -0,0 +1,18 @@
+const addResourcesToCache = async () => {
+    const cache = await caches.open('v1')
+    cache.addAll(['/', '/compositions', '/videos', '/lessons', '/contact'])
+    ;[
+        'https://jessebrault.nyc3.cdn.digitaloceanspaces.com/images/portrait1.jpg',
+        'https://jessebrault.nyc3.cdn.digitaloceanspaces.com/images/portrait2.jpg',
+        'https://jessebrault.nyc3.cdn.digitaloceanspaces.com/images/portrait4.jpg',
+        'https://jessebrault.nyc3.cdn.digitaloceanspaces.com/images/jesse-brault-bratislava.jpg'
+    ].forEach(async url => {
+        const request = new Request(url, { mode: 'no-cors' })
+        const response = await fetch(request)
+        cache.put(request, response)
+    })
+}
+
+self.addEventListener('activate', event => {
+    event.waitUntil(addResourcesToCache())
+})