How can I use add_write_callback to change a node value, and then perform a secondary action?

[Remi-Godin]

Here's what I'm trying to do:

• Have OPC client write a new value to a node
• Internally
  • complete the write
  • if confirmed, then send the data to another service

Here's what I managed to do:

• Have OPC client write a new value to a node
• Internally
  • send data to another service
  • complete the write

let subcriptions_clone = subscriptions.clone();
let manager_clone = manager.clone();
manager
    .inner()
    .add_write_callback(v6_node.clone(), move |dv, nr| {
        info!("WRITING {dv:?}");
        let manager_clone = manager_clone.clone();
        let v6_node = v6_node.clone();
        let dv = dv.clone();

        let subscriptions_clone = subcriptions_clone.clone();
        tokio::spawn(async move {
            let _ = manager_clone
                .set_values(&subscriptions_clone, [(&v6_node, None, dv)].into_iter());
        });

        // Send data to another service

        StatusCode::Good
    });

But now I don't know if the write to the nodes was actually successful, and the data I send to another service might be "out of sync" with the actual node value.

Is there a better way to do this? Is add_write_callback not the way to go? Is the best way to create an internal opc client to subscribe to my server instead? But that seems a bit excessive.

[Remi-Godin]

Nevermind, I was just being dumb. I had tunnel vision and didn't think of just sending the data inside the same tokio task that was writing it in the first place. I guess my hangup was always returning StatusCode::Good from my callback function, but I can live with that.