Reference
applicationCache checking
if (window.applicationCache) {
// "Naturally" reload when an update is available
var reload = false
window.applicationCache.addEventListener('updateready', () => {
if (window.applicationCache.status === window.applicationCache.UPDATEREADY) {
window.applicationCache.swapCache()
reload = true
}
}, false)
setInterval(() => {
try {
// There's nothing to update for first-time load, browser freaks out :/
window.applicationCache.update()
} catch (e) { }
}, 1000 * 60 * 60) // Every hour
}
This is a deprecated HTML feature. See: Using the application cache (developer.mozilla.org)