dom / latest / backgroundfetchupdateuievent.html /

BackgroundFetchUpdateUIEvent

The BackgroundFetchUpdateUIEvent interface of the Background Fetch API is an event type for the backgroundfetchsuccess and backgroundfetchfail events, and provides a method for updating the title and icon of the app to inform a user of the success or failure of a background fetch.

Event ExtendableEvent BackgroundFetchEvent BackgroundFetchUpdateUIEvent

Constructor

BackgroundFetchUpdateUIEvent()

Creates a new BackgroundFetchUIEvent object. This constructor is not typically used, as the browser creates these objects itself for the backgroundfetchsuccess and backgroundfetchfail events.

Properties

This interface doesn't implement any specific properties, but inherits properties from Event, and BackgroundFetchEvent.

Methods

BackgroundFetchUpdateUIEvent.updateUI()

Updates the title and icon in the user interface to show the status of a background fetch. Resolves with a Promise.

Examples

In this example, the backgroundfetchsuccess event is listened for, indicating that a fetch has completed successfully. The updateUI() method is then called, with a message to let the user know the episode they downloaded is ready.

addEventListener('backgroundfetchsuccess', (event) => {
  const bgFetch = event.registration;

  event.waitUntil(async function() {
    // Create/open a cache.
    const cache = await caches.open('downloads');
    // Get all the records.
    const records = await bgFetch.matchAll();
    // Copy each request/response across.
    const promises = records.map(async (record) => {
      const response = await record.responseReady;
      await cache.put(record.request, response);
    });

    // Wait for the copying to complete.
    await Promise.all(promises);

    // Update the progress notification.
    event.updateUI({ title: 'Episode 5 ready to listen!' });
  }());
});

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
BackgroundFetchUpdateUIEvent
74
79
No
No
62
No
No
74
No
53
No
11.0
BackgroundFetchUpdateUIEvent
74
79
No
No
62
No
No
74
No
53
No
11.0
updateUI
74
79
No
No
62
No
No
74
No
53
No
11.0

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/BackgroundFetchUpdateUIEvent