ServiceWorkerRegistration

The ServiceWorkerRegistration interface of the ServiceWorker API represents the service worker registration. You register a service worker to control one or more pages that share the same origin.

The lifetime of a service worker registration is beyond that of the ServiceWorkerRegistration objects that represent them within the lifetime of their corresponding service worker clients. The browser maintains a persistent list of active ServiceWorkerRegistration objects.

Also implements properties from its parent interface, EventTarget.

ServiceWorkerRegistration.scope (en-US) Read only

Returns a unique identifier for a service worker registration. This must be on the same origin as the document that registers the ServiceWorker (en-US).

ServiceWorkerRegistration.installing (en-US) Read only

Returns a service worker whose state is installing. This is initially set to null.

ServiceWorkerRegistration.waiting (en-US) Read only

Returns a service worker whose state is waiting. This is initially set to null.

ServiceWorkerRegistration.active (en-US) Read only

Returns a service worker whose state is either activating or activated. This is initially set to null. An active worker will control a ServiceWorkerClient (en-US) if the client's URL falls within the scope of the registration (the scope option set when ServiceWorkerContainer.register is first called.)

ServiceWorkerRegistration.navigationPreload (en-US) Read only

Returns the instance of NavigationPreloadManager (en-US) associated with the current service worker registration.

serviceWorkerRegistration.periodicSync (en-US) Read only

Returns a reference to the PeriodicSyncManager (en-US) interface, which manages periodic background synchronization processes.

ServiceWorkerRegistration.pushManager (en-US) Read only

Returns a reference to the PushManager interface for managing push subscriptions including subscribing, getting an active subscription, and accessing push permission status.

ServiceWorkerRegistration.sync (en-US)  Read only  

Returns a reference to the SyncManager (en-US) interface, which manages background synchronization processes.

ServiceWorkerRegistration.onupdatefound (en-US) Read only

An EventListener property called whenever an event of type updatefound is fired; it is fired any time the ServiceWorkerRegistration.installing (en-US) property acquires a new service worker.

Also implements methods from its parent interface, EventTarget.

ServiceWorkerRegistration.getNotifications() (en-US)

Returns a Promise that resolves to an array of Notification objects.

ServiceWorkerRegistration.showNotification() (en-US)

Displays the notification with the requested title.

ServiceWorkerRegistration.update() (en-US)

Checks the server for an updated version of the service worker without consulting caches.

ServiceWorkerRegistration.unregister() (en-US)

Unregisters the service worker registration and returns a Promise. The service worker will finish any ongoing operations before it is unregistered.

In this example, the code first checks whether the browser supports service workers and if so registers one. Next, it adds and updatefound event in which it uses the service worker registration to listen for further changes to the service worker's state. If the service worker hasn't changed since the last time it was registered, than the updatefound event will not be fired.

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw.js')
  .then(function(registration) {
    registration.addEventListener('updatefound', function() {
      // If updatefound is fired, it means that there's
      // a new service worker being installed.
      var installingWorker = registration.installing;
      console.log('A new service worker is being installed:',
        installingWorker);

      // You can listen for changes to the installing service worker's
      // state via installingWorker.onstatechange
    });
  })
  .catch(function(error) {
    console.log('Service worker registration failed:', error);
  });
} else {
  console.log('Service workers are not supported.');
}

• Using Service Workers
• Service workers basic code example
• Is ServiceWorker ready?
• Promise
• Using web workers