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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 getEntries()
method returns a list of explicitly observed performance entry
objects for a given filter. The list's members are determined by the set of entry types
specified in the call to the observe()
method. The list is available in the observer's callback function (as the first parameter in the callback).
This method is exposed to Window
and Worker
interfaces.
Syntax
General syntax:
entries = list.getEntries(); entries = list.getEntries(PerformanceEntryFilterOptions);
Specific usage:
entries = list.getEntries({name: "entry_name", entryType: "mark"});
Arguments
- PerformanceEntryFilterOptionsOptional
- Is a
PerformanceEntryFilterOptions
dictionary, having the following fields:"name"
, the name of a performance entry."entryType"
, the entry type. The valid entry types are listed in thePerformanceEntry.entryType
method."initiatorType"
, the type of the initiating resource (for example an HTML element). The values are defined by thePerformanceResourceTiming.initiatorType
interface.
Return value
entries
- A list of explicitly observed
PerformanceEntry
objects that meets the criteria of the filter. The items will be in chronological order based on the entries'startTime
. If no objects that meet the filter are found, an empty list is returned. If no argument is given, all entries are returned.
Example
function print_perf_entry(pe) { console.log("name: " + pe.name + "; entryType: " + pe.entryType + "; startTime: " + pe.startTime + "; duration: " + pe.duration); } // Create observer for all performance event types 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]); } // Print entries named "Begin" with type "mark" perfEntries = list.getEntriesByName("Begin", "mark"); for (var i=0; i < perfEntries.length; i++) { print_perf_entry(perfEntries[i]); } // Print entries with type "mark" perfEntries = list.getEntriesByType("mark"); for (var i=0; i < perfEntries.length; i++) { print_perf_entry(perfEntries[i]); } }); // subscribe to all performance event types observe_all.observe({entryTypes: ['frame', 'mark', 'measure', 'navigation', 'resource', 'server']}); var observe_frame = new PerformanceObserver(function(list, obs) { var perfEntries = list.getEntries(); // Should only have 'frame' entries for (var i=0; i < perfEntries.length; i++) { print_perf_entry(perfEntries[i]); } }); // subscribe to frame event only observe_frame.observe({entryTypes: ['frame']});
Specifications
Specification | Status | Comment |
---|---|---|
Performance Timeline Time Level 2 The definition of 'getEntries()' in that specification. |
Editor's Draft | Initial definition of getEntries() method. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
getEntries() |
No support | No support | No support | No support | No support |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
getEntries() |
No support | No support | No support | No support | No support | No support |