CustomEvent()

The CustomEvent() constructor creates a new CustomEvent.

typeArg

A string representing the name of the event.

options Optional

An object, with the following properties:

• "detail", optional and defaulting to null, of any type, containing an event-dependent value associated with the event. This is available to the handler using the CustomEvent.detail property.
• Any properties that can be used in the init object of the Event() constructor.

// create custom events
const catFound = new CustomEvent('animalfound', {
  detail: {
    name: 'cat'
  }
});
const dogFound = new CustomEvent('animalfound', {
  detail: {
    name: 'dog'
  }
});

// add an appropriate event listener
obj.addEventListener('animalfound', (e) => console.log(e.detail.name));

// dispatch the events
obj.dispatchEvent(catFound);
obj.dispatchEvent(dogFound);

// "cat" and "dog" logged in the console

Additional examples can be found at Creating and triggering events.

• CustomEvent
• Creating and triggering events