PressureRecord: 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.
Note: This feature is available in Web Workers, except for Service Workers.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The toJSON() method of the PressureRecord interface returns a JSON-serializable plain object representing the PressureRecord object.
The method is automatically called by JSON.stringify() when a PressureRecord object is encountered during JSON serialization.
Syntax
toJSON()
Parameters
None.
Return value
A JSON-serializable plain object containing the following properties:
Each property's value is copied as-is.
Examples
Calling toJSON() directly
This example obtains a PressureRecord object. Calling toJSON() directly returns a plain object. Its properties have the same values as the corresponding properties of the original object.
function callback(records) {
const record = records[records.length - 1];
const json = record.toJSON();
console.log(json); // A plain object
console.log(typeof json); // "object"
console.log(json.state); // Same value as record.state
}
try {
const observer = new PressureObserver(callback);
await observer.observe("cpu", {
sampleInterval: 1000, // 1000ms
});
} catch (error) {
// report error setting up the observer
}
Serializing to a JSON string
Within the callback from the previous example, the same object can be serialized using JSON.stringify(), which calls the toJSON() method automatically.
console.log(JSON.stringify(record));
This would log a JSON string like so (formatted for readability):
{
"source": "cpu",
"state": "fair",
"time": 1000.5
}
Specifications
| Specification |
|---|
| Compute Pressure Level 1 # the-tojson-member |