How to stop an eventListener from being called multiple times?

Issue

I have added an eventListener and is being called multiple times. Is there any way to call it only once?

Here is my code snippet.

  this.elements.on('done', function (event) {
  console.log(event);
})

Solution

If you're using Angular you should really look into rxjs. However, for the provided code snippet, a simple solution would be:

const handled = false;
this.elements.on('done', function (event) {
  if (!handled) {
     // do things
     handled = true;
  }
})

Answered By - Nathan