The PerformanceObserver()
constructor creates a new PerformanceObserver
object with the given observer callback
. The observer callback is invoked when performance entry events are recorded for the entry types that have been registered, via the observe()
method.
var observer = new PerformanceObserver(callback);
callback
PerformanceObserverCallback
callback that will be invoked when observed performance events are recorded. When the callback is invoked, its first parameter is a list of performance observer entries and the second parameter is the observer
object.A new PerformanceObserver
object which will call the specified callback
when observed performance events occur.
var observer = new PerformanceObserver(function(list, obj) { var entries = list.getEntries(); for (var i=0; i < entries.length; i++) { // Process "mark" and "frame" events } }); observer.observe({entryTypes: ["mark", "frame"]}); function perf_observer(list, observer) { // Process the "measure" event } var observer2 = new PerformanceObserver(perf_observer); observer2.observe({entryTypes: ["measure"]});
Specification | Status | Comment |
---|---|---|
Performance Timeline Level 2 The definition of 'PerformanceObserver()' in that specification. | Candidate Recommendation | Initial definition of PerformanceObserver() constructor. |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 52 | ? | 57 | No | 39 | 11 |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | No | 52 | ? | 57 | 39 | 11 | ? |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/PerformanceObserver/PerformanceObserver