How do I respond to an incoming event with data?

[mars1211]

I think the problem is not solved. I also came across this and did not find an answer.
When receiving an event, you need to respond to it with data, for example, how it is implemented in the JS version:

socket.on("hello", (arg, callback) => {
  console.log(arg); // "world"
  callback("got it");
});

https://socket.io/docs/v4/#acknowledgements

Can you tell me how to implement this?

Please help, this is a critical thing for me.

Originally posted by @mars1211 in #95 (comment)

[mars1211]

I made this future, and create request as example - #293

[rageshkrishna]

@1c3t3a Would an implementation with the following API be an acceptable solution?

.on("some_message", |payload, client| {
    async move {
        match payload {
            Payload::Binary(_) => todo!(),
            Payload::Text(t) => todo!(),
            Payload::TextAck(t, ack) => {
                client.send_ack(json!({ "ack": "yes" }), ack).await.ok();
            }
        };
    }.boxed()
})

Basically, new TextAck and BinaryAck payload types that indicate the sender expects an acknowledgement to be sent.