PerformanceObserver
The PerformanceObserver
interface is used to observe performance measurement events and be notified of new performance entries as they are recorded in the browser's performance timeline.
Note: This feature is available in Web Workers
Constructor
PerformanceObserver()
-
Creates and returns a new
PerformanceObserver
object.
Properties
PerformanceObserver.supportedEntryTypes
Read only-
Returns an array of the
entryType
values supported by the user agent.
Methods
PerformanceObserver.observe()
-
Specifies the set of
entry types
to observe. The performance observer's callback function will be invoked when aperformance entry
is recorded for one of the specifiedentryTypes
PerformanceObserver.disconnect()
-
Stops the performance observer callback from receiving
performance entries
. PerformanceObserver.takeRecords()
-
Returns the current list of
performance entries
stored in the performance observer, emptying it out.
Example
function observer_callback(list, observer) {
// Process the "measure" event
}
let observer = new PerformanceObserver(observer_callback);
observer.observe({entryTypes: ["measure"]});
Specifications
Specification |
---|
Performance Timeline # dom-performanceobserver |
Browser compatibility
BCD tables only load in the browser