BackgroundFetchUpdateUIEvent
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
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.
Constructor
BackgroundFetchUpdateUIEvent()
Experimental-
Creates a new
BackgroundFetchUIEvent
object. This constructor is not typically used, as the browser creates these objects itself for thebackgroundfetchsuccess
andbackgroundfetchfail
events.
Instance properties
This interface doesn't implement any specific properties, but inherits properties from Event
, and BackgroundFetchEvent
.
Instance methods
BackgroundFetchUpdateUIEvent.updateUI()
Experimental-
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.
js
addEventListener("backgroundfetchsuccess", (event) => {
const bgFetch = event.registration;
event.waitUntil(
(async () => {
// 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
Specification |
---|
Background Fetch # background-fetch-update-ui-event |
Browser compatibility
BCD tables only load in the browser