Unable to get the Socket.IO ACK to work

[MelvinQM]

Hello,

For a project I require the use of Socket.IO but I can't seem to get the ACK to send properly and am not sure where to look for mistakes.

Without requesting an ACK the code worked. Im trying to send a message from a web interface to the server which then sends the message to the arduino environment (another client) then I want this to send back an ACK which then in turn will tell the server to send the web interface an ACK.

Here is the code for the sender:

I hope someone can offer me some tips in dealing with this problem!

[MelvinQM]

I seem to have found the answer to my own problem:

The template code for the ACK seems to have a mistake.

// Message Includes a ID for a ACK (callback)
if(id) {
    // creat JSON message for Socket.IO (ack)
    DynamicJsonDocument docOut(1024);
    JsonArray array = docOut.to<JsonArray>();

    // add payload (parameters) for the ack (callback function)
    JsonObject param1 = array.createNestedObject();
    param1["now"] = millis();

    // JSON to String (serializion)
    String output;
    //output += id;
    serializeJson(docOut, output);
    output = id + output; // This worked as a fix for me

    // Send event
    socketIO.send(sIOtype_ACK, output);
}