ServiceWorkerGlobalScope: install event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2018.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is only available in Service Workers.

The install event of the ServiceWorkerGlobalScope interface is fired when a ServiceWorkerRegistration acquires a new ServiceWorkerRegistration.installing worker.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("install", (event) => {});

oninstall = (event) => {};

Event type

An ExtendableEvent. Inherits from Event.

Event ExtendableEvent

Event properties

Doesn't implement any specific properties, but inherits properties from its parent, Event.

Examples

The following snippet shows how an install event handler can be used to populate a cache with a number of responses, which the service worker can then use to serve assets offline:

js
self.addEventListener("install", (event) => {
  event.waitUntil(
    caches
      .open("v1")
      .then((cache) =>
        cache.addAll([
          "/",
          "/index.html",
          "/style.css",
          "/app.js",
          "/image-list.js",
          "/star-wars-logo.jpg",
          "/gallery/",
          "/gallery/bountyHunters.jpg",
          "/gallery/myLittleVader.jpg",
          "/gallery/snowTroopers.jpg",
        ]),
      ),
  );
});

You can also set up the event handler using the oninstall property:

js
self.oninstall = (event) => {
  // ...
};

Specifications

Specification
Service Workers
# dom-serviceworkerglobalscope-oninstall

Browser compatibility

BCD tables only load in the browser

See also