The CustomEvent()
constructor creates a new
CustomEvent
.
Note:
This feature is available in Web Workers.Syntax
event = new CustomEvent(typeArg, customEventInit);
Parameters
typeArg
- A
DOMString
representing the name of the event. customEventInit
Optional- A
CustomEventInit
dictionary, having the following fields:"detail"
, optional and defaulting tonull
, of type any, that is an event-dependent value associated with the event.
The
CustomEventInit
dictionary also accepts fields from theEventInit
dictionary.
Return value
A new CustomEvent
object of the specified type, with any other properties
configured according to the CustomEventInit
dictionary (if one was
provided).
Example
// add an appropriate event listener
obj.addEventListener("cat", function(e) { process(e.detail) });
// create and dispatch the event
var event = new CustomEvent("cat", {
detail: {
hazcheeseburger: true
}
});
obj.dispatchEvent(event);
Additional examples can be found at Creating and triggering events.
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'CustomEvent()' in that specification. |
Living Standard | Initial definition. |
Browser compatibility
BCD tables only load in the browser
Polyfill
You can polyfill the CustomEvent()
constructor functionality in Internet
Explorer 9 and higher with the following code:
(function () {
if ( typeof window.CustomEvent === "function" ) return false;
function CustomEvent ( event, params ) {
params = params || { bubbles: false, cancelable: false, detail: null };
var evt = document.createEvent( 'CustomEvent' );
evt.initCustomEvent( event, params.bubbles, params.cancelable, params.detail );
return evt;
}
window.CustomEvent = CustomEvent;
})();
Internet Explorer >= 9 adds a CustomEvent object to the window, but with correct implementations, this is a function.