BackgroundFetchUpdateUIEvent.md

BackgroundFetchUpdateUIEvent

Namespace: SpawnDev.SpawnJS.JSObjects
Inherits: BackgroundFetchEvent
Source: JSObjects/BackgroundFetchUpdateUIEvent.cs
MDN Reference: BackgroundFetchUpdateUIEvent on MDN

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. https://developer.mozilla.org/en-US/docs/Web/API/BackgroundFetchUpdateUIEvent

Methods

Method	Return Type	Description
UpdateUI(UpdateUIOptions? options)	Task	The updateUI() method of the BackgroundFetchUpdateUIEvent interface updates the title and icon in the user interface to show the status of a background fetch. This method may only be run once, to notify the user on a failed or a successful fetch.

Examples

SpawnDev.SpawnJS Mapping Note: The JavaScript examples below show the standard Web API usage. In SpawnDev.SpawnJS, the same API is available with C# conventions:

• Properties and methods use PascalCase (e.g., readyState becomes ReadyState)
• Events use ActionEvent with +=/-= (e.g., addEventListener("click", fn) becomes OnClick += handler)
• Async methods return Task<T> instead of Promise<T>
• Objects should be disposed with using statements
• Access via JS.Get<BackgroundFetchUpdateUIEvent>(...) or constructor new BackgroundFetchUpdateUIEvent(...)

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!" });
    })(),
  );
});

See full example on MDN