The toJSON()
method of the PerformanceElementTiming
interface is a standard serializer. It returns a JSON representation of the object's properties.
PerformanceElementTiming.toJSON()
Syntax
toJSON()
Return value
- json
-
A JSON object that is the serialization of the
PerformanceElementTiming
object.
Examples
In this example calling entry.toJSON()
returns a JSON representation of the PerformanceElementTiming
object, with the information about the image element.
<img src="image.jpg" alt="a nice image" elementtiming="big-image" id="myImage">
const observer = new PerformanceObserver((list) => { let entries = list.getEntries().forEach(function (entry) { if (entry.identifier === "big-image") { console.log(entry.toJSON()); } }); }); observer.observe({ entryTypes: ["element"] });
Note: This example uses the PerformanceObserver
interface to create a list of performance measurement events. In our case we observe the PerformanceEntry.entrytype
element
in order to use the PerformanceElementTiming
interface.
Specifications
Specification |
---|
Element Timing API # dom-performanceelementtiming-tojson |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
toJSON |
77
|
79
|
No
|
No
|
64
|
No
|
77
|
77
|
No
|
55
|
No
|
12.0
|
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https://developer.mozilla.org/en-US/docs/Web/API/PerformanceElementTiming/toJSON