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.
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 perf_observer(list, observer) {
// Process the "measure" event
}
var observer2 = new PerformanceObserver(perf_observer);
observer2.observe({entryTypes: ["measure"]});
Specifications
Specification | Status | Comment |
---|---|---|
Performance Timeline Level 2 The definition of 'PerformanceObserver' in that specification. |
Candidate Recommendation | Initial definition of PerformanceObserver interface. |
Browser compatibility
BCD tables only load in the browser