In this section you're going to learn how to use event acknowledgments. That's a fantastic feature inside Socket.io. In order to illustrate exactly what they are and why you'd ever want to use them, we're going to quickly run through the diagram for the chat app. These are the two events that we actually have in our application, if you remember the first one is the newMessage Event, it gets emitted by the server and it gets listened to by the client, it sends across the from, text, and createdAt properties, all of which are required to render the message to the screen:
Now the event that we're going to be updating is the createMessage Event. This one gets emitted by the client and listened to by the server:
Once again we are sending some data across from and text. Now the problem with our createMessage Event is that the data flows in one direction. The data comes from a form inside the browser. It then gets sent over to the server and the server is kind of stuck. Sure...