The PromiseRejectionEvent
interface's promise
read-only property indicates the JavaScript Promise
which was rejected. You can examine the event's PromiseRejectionEvent.reason
property to learn why the promise was rejected.
Syntax
promise = PromiseRejectionEvent.promise
Value
The JavaScript Promise
which was rejected, and whose rejection went unhandled.
Examples
This example listens for unhandled promises and, if the reason
is an object with a code
field containing the text "Module not ready", it sets up an idle callback that will retry the task that failed to execute correctly.
event.preventDefault()
is called to indicate that the promise has now been handled.
window.onunhandledrejection = function(event) { if (event.reason.code && event.reason.code == "Module not ready") { window.requestIdleCallback(function(deadline) { loadModule(event.reason.moduleName) .then(performStartup); }); event.preventDefault(); } }
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'PromiseRejectionEvent.promise' in that specification. |
Living Standard | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
promise | Chrome Full support 49 | Edge Full support ≤79 | Firefox
Full support
69
| IE No support No | Opera Full support 36 | Safari Full support 11 | WebView Android Full support 49 | Chrome Android Full support 49 | Firefox Android
Full support
68
| Opera Android Full support 36 | Safari iOS Full support 11.3 | Samsung Internet Android Full support 5.0 |
Legend
- Full support
- Full support
- No support
- No support
- User must explicitly enable this feature.
- User must explicitly enable this feature.