JAVASCRIPT

custom event handler javascript

const event = new Event('build');

// Listen for the event.
elem.addEventListener('build', (e) => { /* … */ }, false);

// Dispatch the event.
elem.dispatchEvent(event);

custom event js

const eventDetails = {
  'id': elemId
}
document.dispatchEvent (
  new CustomEvent('myCustomEvent', {'detail': eventDetails})
)

js custom event

// create a custom event
const custom_event = new CustomEvent("custom_event_name", {
	// whether or not the event 'bubbles' up the DOM tree
	bubbles: true,
	// special property allowing you to provide additional information
	detail: {
		
	}
});

// to add an event listener
element.addEventListener("custom_event_name", function() {
	// event handler
});

// to trigger an event
element.dispatchEvent(custom_event);

Custom Event Example

		 const btn1 = document.getElementById('btn1');

			   btn1.addEventListener('boo', function () {
			          alert('Button1 said Boo');
			   });
			   
			   
  			 const btn2 = document.getElementById('btn2');

  			   btn2.addEventListener('boo', function () {
  			          alert('Button 2 said Boo');
  			   });
			   			  const clickEvent = new Event('boo');
			   btn1.dispatchEvent(clickEvent);

			  btn2.dispatchEvent(clickEvent);