PerformanceLongTaskTiming: toJSON() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The toJSON() method of the PerformanceLongTaskTiming interface is a serializer; it returns a JSON representation of the PerformanceLongTaskTiming object.
Syntax
js
toJSON()
Parameters
None.
Return value
A JSON object that is the serialization of the PerformanceLongTaskTiming object.
Examples
Using the toJSON method
In this example, calling entry.toJSON() returns a JSON representation of the PerformanceLongTaskTiming object.
js
const observer = new PerformanceObserver((list) => {
list.getEntries().forEach((entry) => {
console.log(entry.toJSON());
});
});
observer.observe({ type: "longtask", buffered: true });
This would log a JSON object like so:
json
{
"name": "self",
"entryType": "longtask",
"startTime": 183,
"duration": 60,
"attribution": [
{
"name": "unknown",
"entryType": "taskattribution",
"startTime": 0,
"duration": 0,
"containerType": "window",
"containerSrc": "",
"containerId": "",
"containerName": ""
}
]
}
To get a JSON string, you can use JSON.stringify(entry) directly; it will call toJSON() automatically.
Specifications
| Specification |
|---|
| Long Tasks API # dom-performancelongtasktiming-tojson |
Browser compatibility
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