Transport implementation questions

[iccicci]

Hi all,

I'm planning to write a new winston transport; looking at the log method example in the readme it seems that the log method has to fire a logged event, but since I like to understand what I'm writing rather than simply to cut&paste code, I have some question about it.

This is the log method example in the readme:

log(info, callback) {
  setImmediate(() => {
    this.emit('logged', info);
  });

  // Perform the writing to the remote service

  callback();
}

1. Why should logged event be fired? I would have thought that callback was enough.
2. Why should it be fired within a setImmediate?
3. The name is confusing me. I would have expected to fire something like logging before writing data to the remote service and something like logged later. Is it ok that logged event should be fired before writing the data to the remote service?

Thank you,
iCC

[Limsanity]

It seems you don't have to emit the event.
winston use the feature in test file, such as http.test.js.

[ozanbaskan]

setImmediate pushes the function to the callback queue, stack is prioritized over callback queue so if you don't use timers to send your logs to a remote service, setImmediate function is most likely to execute last.