Missing Gulp Events in 4.0

Question

In Gulp 3.x there was the ability to tie into its event system with Orchestrator to do things when a task starts or a task ends by using the task_start , task_stop or stop listeners.

Example:

gulp.on('task_start', (e) => {
  // Task event information
  console.log(e);
});

It seems Gulp has removed Orchestrator and replaced it with a new library called Undertaker. However, I can't find any reference to an internal API event system now in Gulp.

Is there any way to achieve these type of events in a custom Gulp plugin still in version 4.x?

Answer 1

tl;dr:

use gulp.on('start', callback) , gulp.on('stop', callback) and gulp.on('error', callback)

---

Undertaker inherits from EventEmitter library. (you can find its API docs here )

in Undertaker, this is the file responsible for emitting the above cited event. You can check it out to see what's being passed to the callback function.

PS : Since version 4 release, Gulp documentation has become a bit of a mess, I'm struggling with this too, finding conflicting docs between 3 and 4, with no clear deprecation warnings with version 3 docs. So checking the source code for undocumented parts of the API can be of a great help.