PerformanceObserverEntryList: getEntries() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
Note: This feature is available in Web Workers.
The getEntries()
method of the PerformanceObserverEntryList
interface returns a list of explicitly observed performance entry objects. 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).
Syntax
getEntries()
Return value
A list of explicitly observed PerformanceEntry
objects. The items will be in chronological order based on the entries' startTime
. If no objects are found, an empty list is returned.
Examples
Working with getEntries, getEntriesByName and getEntriesByType
The following example shows the difference between the getEntries()
, getEntriesByName()
, and getEntriesByType()
methods.
const observer = new PerformanceObserver((list, obs) => {
// Log all entries
let perfEntries = list.getEntries();
perfEntries.forEach((entry) => {
console.log(`${entry.name}'s duration: ${entry.duration}`);
});
// Log entries named "debugging" with type "measure"
perfEntries = list.getEntriesByName("debugging", "measure");
perfEntries.forEach((entry) => {
console.log(`${entry.name}'s duration: ${entry.duration}`);
});
// Log entries with type "mark"
perfEntries = list.getEntriesByType("mark");
perfEntries.forEach((entry) => {
console.log(`${entry.name}'s startTime: ${entry.startTime}`);
});
});
// Subscribe to various performance event types
observer.observe({
entryTypes: ["mark", "measure", "navigation", "resource"],
});
Specifications
Specification |
---|
Performance Timeline # dom-performanceobserverentrylist-getentries |
Browser compatibility
BCD tables only load in the browser