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 PerformanceObserverEntryList
interface is a list of peformance events that were explicitly observed via the observe()
method.
Note: this interface is exposed to Window
and Worker
.
Methods
PerformanceObserverEntryList.getEntries()
- Returns a list of explicitly observed
PerformanceEntry
objects based on the given filter. PerformanceObserverEntryList.getEntriesByType()
- Returns a list of explicitly observed
PerformanceEntry
objects of the given entry type. PerformanceObserverEntryList.getEntriesByName()
- Returns a list of explicitly observed
PerformanceEntry
objects based on the given name and entry type.
Example
// Create observer for all performance event types // list is of type PerformanceObserveEntryList var observe_all = new PerformanceObserver(function(list, obs) { var perfEntries; // Print all entries perfEntries = list.getEntries(); for (var i=0; i < perfEntries.length; i++) { print_perf_entry(perfEntries[i]); // do something with it } }
Specifications
Specification | Status | Comment |
---|---|---|
Performance Timeline Time Level 2 The definition of 'PerformanceObserverEntryList' in that specification. |
Editor's Draft | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 52.0 | 49 (49)[1] | No support | 39 | No support |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | No support | No support | 49.0 (49)[1] | No support | 39 | No support | 52.0 |
[1] Only activated in Nightly builds. Controlled by the dom.enable_performance_observer
preference.