Facebook 如何在没有标签的情况下发送通知

Question

1. Go to facebook and allow HTML5 Desktop Notification for it.
2. Close facebook tab.
3. Ask somebody to write you message on facebook.

Now u see the notification from facebook while facebook site isn't open. HOW?

Answer 1

Facebook uses the Push Notifications API: https://www.w3.org/TR/push-api/

More information:

• https://developers.google.com/web/fundamentals/push-notifications/
• https://developers.google.com/web/fundamentals/getting-started/push-notifications/

Answer 2

They use the Push API - https://developer.mozilla.org/en-US/docs/Web/API/Push_API Quoting from there:

The Push API gives web applications the ability to receive messages pushed to them from a server, whether or not the web app is in the
foreground, or even currently loaded, on a user agent.