The cancelable
read-only property of the Event
interface indicates whether the event can be canceled, and therefore prevented as if the event never happened. If the event is not cancelable, then its cancelable
property will be false
and the event listener cannot stop the event from occurring.
Event listeners that handle multiple kinds of events may want to check cancelable
before invoking their preventDefault()
methods.
Most browser-native events that can be canceled are the ones that result from the user interacting with the page. Canceling the click
, scroll
, or beforeunload
events would prevent the user from clicking on something, scrolling the page, or navigating away from the page, respectively.
Custom events created by other JavaScript code control if they can be canceled when they are created.
Syntax
bool = event.cancelable;
Value
The result is a Boolean
, which is true
if the event can be canceled.
Example
For example, browser vendors are proposing that the wheel
event can only be canceled the first time the listener is called — any following wheel
events cannot be canceled.
function preventScrollWheel(event) { if (typeof event.cancelable !== 'boolean' || event.cancelable) { // The event can be canceled, so we do so. event.preventDefault(); } else { // The event cannot be canceled, so it is not safe // to call preventDefault() on it. console.warn(`The following event couldn't be canceled:`); console.dir(event); } } document.addEventListener('wheel', preventScrollWheel);
Notes
Whether an event can be canceled or not is something that's determined when that event is initialized.
To cancel an event, call the preventDefault()
method on the event. This keeps the implementation from executing the default action that is associated with the event.
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'Event.cancelable' in that specification. |
Living Standard | |
Document Object Model (DOM) Level 2 Events Specification The definition of 'Event.cancelable' in that specification. |
Obsolete | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
cancelable | Chrome Full support Yes | Edge Full support 12 | Firefox Full support Yes | IE ? | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- Compatibility unknown
- Compatibility unknown