The ExtendableEvent interface extends the lifetime of the install and activate events dispatched on the global scope as part of the service worker lifecycle. This ensures that any functional events (like FetchEvent) are not dispatched until it upgrades database schemas and deletes the outdated cache entries.
The W3C Push API offers some exciting new functionality for developers to use in web applications: this article provides an introduction to getting Push notifications setup and running, with a simple demo.
The endpoint read-only property of the PushSubscription interface returns a DOMString containing the subscription ID associated with the push subscription.