The ContentIndexEvent interface of the content index defines the object used to represent the contentdelete event.

This event is sent to the global scope of a ServiceWorker. It contains the id of the indexed content to be removed.

The contentdelete event is only fired when the deletion happens due to interaction with the browser's built-in user interface. It is not fired when the ContentIndex.delete method is called.

ContentIndexEvent() Experimental

Creates and returns a new ContentIndexEvent object whose type and other options are configured as specified.

In addition to the properties listed below, this interface inherits the properties of its parent interface, ExtendableEvent.

id Read only Experimental

A String which identifies the deleted content index via it's id.

While ContentIndexEvent offers no methods of its own, it inherits any specified by its parent interface, ExtendableEvent.

This example shows the service worker script listening for the contentdelete event and logs the removed content index id.

self.addEventListener("contentdelete", (event) => {
  console.log(event.id);

  // logs content index id, which can then be used to determine what content to delete from your cache
});

• An introductory article on the Content Index API
• An app which uses the Content Index API to list and remove 'save for later' content
• Service Worker API, along with information about Cache and CacheStorage