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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
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).
Syntax
var observer = new PerformanceObserver(callback);
Arguments
- callback
- A
PerformanceObserverCallback
callback that will be invoked when observered performance events are recorded. When the callback is invoked, its first parameter is alist of performance observer entries
and the second parameter is theobserver
object.
Example
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"]});
Specifications
Specification | Status | Comment |
---|---|---|
Performance Timeline Time Level 2 The definition of 'PerformanceObserver()' in that specification. |
Editor's Draft | Initial definition of PerformanceObserver() constructor. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
PerformanceObserver() |
No support | No support | No support | No support | No support |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
PerformanceObserver() |
No support | No support | No support | No support | No support | No support |