MediaDeviceInfo: toJSON() method
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since October 2018.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The toJSON() method of the MediaDeviceInfo interface returns a JSON-serializable plain object representing the MediaDeviceInfo object.
The method is automatically called by JSON.stringify() when a MediaDeviceInfo 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 MediaDeviceInfo object. Calling toJSON() directly returns a plain object. Its properties have the same values as the corresponding properties of the original object.
if (!navigator.mediaDevices || !navigator.mediaDevices.enumerateDevices) {
console.log("enumerateDevices() not supported.");
} else {
// List cameras and microphones.
navigator.mediaDevices
.enumerateDevices()
.then((devices) => {
devices.forEach((device) => {
const json = device.toJSON();
console.log(json); // A plain object
console.log(typeof json); // "object"
console.log(json.deviceId); // Same value as device.deviceId
});
})
.catch((err) => {
console.log(`${err.name}: ${err.message}`);
});
}
Serializing to a JSON string
Within the forEach() callback from the previous example, the same object can be serialized using JSON.stringify(), which calls the toJSON() method automatically.
console.log(JSON.stringify(device));
This would log a JSON string like so (formatted for readability):
{
"deviceId": "HJtTemQTM64Bivxv3ZEyKjCi1VR8042lPNpmXKObKJE=",
"kind": "videoinput",
"label": "",
"groupId": "Okm2l1YZTrwy8awTxE8QSLNFoVMdIXx++wLh68tbmv0="
}
Each additional device is logged as a separate JSON string.
Specifications
| Specification |
|---|
| Media Capture and Streams # dom-mediadeviceinfo-tojson |