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Event

The Event interface represents an event which takes place in the DOM.

An event can be triggered by the user action e.g. clicking the mouse button or tapping keyboard, or generated by APIs to represent the progress of an asynchronous task. It can also be triggered programmatically, such as by calling the HTMLElement.click() method of an element, or by defining the event, then sending it to a specified target using EventTarget.dispatchEvent().

There are many types of events, some of which use other interfaces based on the main Event interface. Event itself contains the properties and methods which are common to all events.

Many DOM elements can be set up to accept (or "listen" for) these events, and execute code in response to process (or "handle") them. Event-handlers are usually connected (or "attached") to various HTML elements (such as <button>, <div>, <span>, etc.) using EventTarget.addEventListener(), and this generally replaces using the old HTML event handler attributes. Further, when properly added, such handlers can also be disconnected if needed using removeEventListener().

Note: One element can have several such handlers, even for the exact same event—particularly if separate, independent code modules attach them, each for its own independent purposes. (For example, a webpage with an advertising-module and statistics-module both monitoring video-watching.)

When there are many nested elements, each with its own handler(s), event processing can become very complicated—especially where a parent element receives the very same event as its child elements because "spatially" they overlap so the event technically occurs in both, and the processing order of such events depends on the Event bubbling and capture settings of each handler triggered.

Interfaces based on Event

Constructor

Event()

Creates an Event object, returning it to the caller.

Instance properties

Event.bubbles Read only

A boolean value indicating whether or not the event bubbles up through the DOM.

Event.cancelable Read only

A boolean value indicating whether the event is cancelable.

Event.composed Read only

A boolean indicating whether or not the event can bubble across the boundary between the shadow DOM and the regular DOM.

Event.currentTarget Read only

A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent. It's possible this has been changed along the way through retargeting.

Event.defaultPrevented Read only

Indicates whether or not the call to event.preventDefault() canceled the event.

Event.eventPhase Read only

Indicates which phase of the event flow is being processed. It is one of the following numbers: NONE, CAPTURING_PHASE, AT_TARGET, BUBBLING_PHASE.

Event.isTrusted Read only

Indicates whether or not the event was initiated by the browser (after a user click, for instance) or by a script (using an event creation method, for example).

Event.target Read only

A reference to the object to which the event was originally dispatched.

Event.timeStamp Read only

The time at which the event was created (in milliseconds). By specification, this value is time since epoch—but in reality, browsers' definitions vary. In addition, work is underway to change this to be a DOMHighResTimeStamp instead.

Event.type Read only

The name identifying the type of the event.

Legacy and non-standard properties

Event.cancelBubble Deprecated

A historical alias to Event.stopPropagation() that should be used instead. Setting its value to true before returning from an event handler prevents propagation of the event.

Event.explicitOriginalTarget Non-standard Read only

The explicit original target of the event.

Event.originalTarget Non-standard Read only

The original target of the event, before any retargetings.

Event.returnValue Deprecated

A historical property still supported in order to ensure existing sites continue to work. Use Event.preventDefault() and Event.defaultPrevented instead.

Event.scoped Read only Deprecated

A boolean value indicating whether the given event will bubble across through the shadow root into the standard DOM. Use composed instead.

Instance methods

Event.composedPath()

Returns the event's path (an array of objects on which listeners will be invoked). This does not include nodes in shadow trees if the shadow root was created with its ShadowRoot.mode closed.

Event.preventDefault()

Cancels the event (if it is cancelable).

Event.stopImmediatePropagation()

For this particular event, prevent all other listeners from being called. This includes listeners attached to the same element as well as those attached to elements that will be traversed later (during the capture phase, for instance).

Event.stopPropagation()

Stops the propagation of events further along in the DOM.

Deprecated methods

Event.initEvent() Deprecated

Initializes the value of an Event created. If the event has already been dispatched, this method does nothing. Use the constructor (Event() instead).

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
Event 15 12 11 No 11.6 6 4.4 18 14 12 6 1.0
Event 1 12 1 6 4 1 ≤37 18 4 10.1 1 1.0
bubbles 1 12 1.5 9 ≤12.1 1 ≤37 18 4 ≤12.1 1 1.0
cancelBubble
1Starting with Chrome 58 and Opera 45, setting this property to false does nothing, as per spec discussion.
12 53
1–53Only supported for UIEvent, not all Event objects.
9
≤12.1Starting with Chrome 58 and Opera 45, setting this property to false does nothing, as per spec discussion.
1
≤37Starting with Chrome 58 and Opera 45, setting this property to false does nothing, as per spec discussion.
18Starting with Chrome 58 and Opera 45, setting this property to false does nothing, as per spec discussion.
53
4–53Only supported for UIEvent, not all Event objects.
≤12.1Starting with Chrome 58 and Opera 45, setting this property to false does nothing, as per spec discussion.
1
1.0Starting with Samsung Internet 7.0 and Opera 45, setting this property to false does nothing, as per spec discussion.
cancelable 1 12 1.5 9 ≤12.1 1 ≤37 18 4 ≤12.1 1 1.0
composed 53 79
52Before Firefox 95, this property was incorrectly set to false on <select> and <input type='checkbox'> elements.
No 40 10 53 53
52Before Firefox 95, this property was incorrectly set to false on <select> and <input type='checkbox'> elements.
41 10 6.0
composedPath 5350–53 79 59 No 4037–40 10 5350–53 5350–53 59 4137–41 10 6.05.0–6.0
currentTarget 1 12 1 9
6–9On Internet Explorer 6 through 8, the event model is different. Event listeners are attached with the non-standard EventTarget.attachEvent method. In this model, there is no equivalent to event.currentTarget and this is the global object. One solution to emulate the event.currentTarget feature is to wrap your handler in a function calling the handler using Function.prototype.call with the element as a first argument. This way, this will be the expected value.
7 1 4.4 18 4 10.1 1 1.0
defaultPrevented 5 12 6 9 11 5 3 18 6 11 5 1.0
eventPhase 1 12 1.5 9 ≤12.1 1 4.4 18 4 ≤12.1 1 1.0
explicitOriginalTarget No No 1.5 No No No No No 4 No No No
initEvent 1 12 17
1–17Before Firefox 17, a call to this method after the dispatching of the event raised an exception instead of doing nothing.
9 ≤12.1 1 ≤37 18 17
4–17Before Firefox 17, a call to this method after the dispatching of the event raised an exception instead of doing nothing.
≤12.1 1 1.0
isTrusted
46Starting with Chrome 53 and Opera 40, untrusted events do not invoke the default action.
12 1.5
9In Internet Explorer, all events are trusted except those that are created with the createEvent() method.
33Starting with Chrome 53 and Opera 40, untrusted events do not invoke the default action.
10
46Starting with version 53, untrusted events do not invoke the default action.
46Starting with Chrome 53 and Opera 40, untrusted events do not invoke the default action.
4
33Starting with Chrome 53 and Opera 40, untrusted events do not invoke the default action.
10
5.0Starting with Samsung Internet 6.0 and Opera 40, untrusted events do not invoke the default action.
originalTarget No No 1.5 No No No No No 4 No No No
preventDefault 1 12 1 9 7 1 4.4 18 4 10.1 1 1.0
returnValue 1 12 6663–64 6 15 1 ≤37 18 6663–64 14 1 1.0
srcElement 1 12 62 9 ≤12.1 1 ≤37 18 62 ≤12.1 1 1.0
stopImmediatePropagation 5 12 10 9 ≤12.1 5 ≤37 18 10 ≤12.1 5 1.0
stopPropagation 1 12 1 9 7 1 4.4 18 4 10.1 1 1.0
target 1 12 1 9 7 1 4.4 18 4 10.1 1 1.0
timeStamp
1Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
12
1.5Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
9Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
≤12.1Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
1
1Starting with version 49, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
18Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
4Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
≤12.1Starting with Chrome 49, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
1
1.0Starting with Samsung Internet 5.0, Firefox 54 and Opera 36, this property returns DOMHighResTimeStamp instead of DOMTimeStamp.
type 1 12 1.5 9 7 1 4.4 18 4 10.1 1 1.0

See also

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https://developer.mozilla.org/en-US/docs/Web/API/Event