This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

 

The parameter passed into the oninstall handler, the InstallEvent interface represents an install action that is dispatched on the ServiceWorkerGlobalScope of a ServiceWorker. As a child of ExtendableEvent, it ensures that functional events such as FetchEvent are not dispatched during installation. 

This interface inherits from the ExtendableEvent interface.

Constructor

InstallEvent.InstallEvent()
Creates a new InstallEvent object.

Properties

Inherits properties from its ancestor, Event.

InstallEvent.activeWorker Read only
Returns the ServiceWorker that is currently controlling the page.

Methods

Inherits methods from its parent, ExtendableEvent.

Examples

This code snippet is from the service worker prefetch sample (see prefetch running live.) The code calls ExtendableEvent.waitUntil() in ServiceWorkerGlobalScope.oninstall and delays treating the ServiceWorkerRegistration.installing worker as installed until the passed promise resolves successfully. The promise resolves when all resources have been fetched and cached, or when any exception occurs.

The code snippet also shows a best practice for versioning caches used by the service worker. Although this example has only one cache, you can use this approach for multiple caches. The code maps a shorthand identifier for a cache to a specific, versioned cache name.

Note: Logging statements are visible in Google Chrome via the "Inspect" interface for the relevant service worker accessed via chrome://serviceworker-internals.

var CACHE_VERSION = 1;
var CURRENT_CACHES = {
  prefetch: 'prefetch-cache-v' + CACHE_VERSION
};

self.addEventListener('install', function(event) {
  var urlsToPrefetch = [
    './static/pre_fetched.txt',
    './static/pre_fetched.html',
    'https://www.chromium.org/_/rsrc/1302286216006/config/customLogo.gif'
  ];

console.log('Handling install event. Resources to pre-fetch:', urlsToPrefetch);

  event.waitUntil(
    caches.open(CURRENT_CACHES['prefetch']).then(function(cache) {
      cache.addAll(urlsToPrefetch.map(function(urlToPrefetch) {
        return new Request(urlToPrefetch, {mode: 'no-cors'});
      })).then(function() {
        console.log('All resources have been fetched and cached.');
      });
    }).catch(function(error) {
      console.error('Pre-fetching failed:', error);
    })
  );
});

Specifications

Specification Status Comment
Service Workers Working Draft As of May 2015, the install event is an instance of ExtendableEvent rather than a child of it.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Experimental
Chrome Full support 40Edge ? Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 & 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari No support NoWebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS No support NoSamsung Internet Android Full support 4.0
InstallEvent() constructor.
Experimental
Chrome Full support 40Edge ? Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 & 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari No support NoWebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS No support NoSamsung Internet Android Full support 4.0
activeWorker
Experimental
Chrome Full support 40Edge ? Firefox Full support 44
Notes
Full support 44
Notes
Notes Service workers (and Push) have been disabled in the Firefox 45 & 52 Extended Support Releases (ESR).
IE No support NoOpera Full support 27Safari No support NoWebView Android Full support 40Chrome Android Full support 40Edge Mobile ? Firefox Android Full support 44Opera Android Full support 27Safari iOS No support NoSamsung Internet Android Full support 4.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.

See also

Document Tags and Contributors

Contributors to this page: duduindo, fscholz, jpmedley, chrisdavidmills, Sebastianz, wt1125
Last updated by: duduindo,