customs event

// First create the event
var myEvent = new CustomEvent("userLogin", {
	detail: {
		username: "davidwalsh"
	}
});

//Listener event 

myElement.addEventListener("userLogin", function(e) {

	console.info("Event is: ", e);
	console.info("Custom data is: ", e.detail);
})

// Trigger it! myElement.dispatchEvent(myEvent);
详细请到此URL:https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent