Glossary: Real-Time Apps with WebSockets

Acknowledgement (ack)

Also written: ack, acks, acknowledgements, emitWithAck

A reply to one Socket.IO event. The receiver calls the ack function it was given, and the sender gets the answer, as when the board learns the server accepted "Ready" for Dana's order. `emitWithAck` lets the browser `await` it.

Where the book teaches it

Chapter 4: Socket.IO
Chapter 5: Rooms, broadcasting and presence
Chapter 6: Authenticating connections
Chapter 10: Testing real-time code
Chapter 11: Project: a live order board for the baristas

Related terms

Socket.IO Named events