PerformanceSoftNavigation: toJSON() method

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The toJSON() method of the PerformanceSoftNavigation interface returns a JSON-serializable plain object representing the PerformanceSoftNavigation object.

The method is automatically called by JSON.stringify() when a PerformanceSoftNavigation object is encountered during JSON serialization.

Syntax

toJSON()

Return value

A JSON-serializable plain object containing the following properties:

Each property's value is copied as-is.

This example obtains a PerformanceSoftNavigation object. Calling toJSON() directly returns a plain object. Its properties have the same values as the corresponding properties of the original object.

const observer = new PerformanceObserver((list) => {
  list.getEntries().forEach((entry) => {
    const json = entry.toJSON();
    console.log(json); // A plain object
    console.log(typeof json); // "object"
    console.log(json.navigationType); // Same value as entry.navigationType
  });
});

observer.observe({ type: "soft-navigation", buffered: true });

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(entry));

This would log a JSON string like so (formatted for readability):

json

{
  "name": "https://www.example.com/#2",
  "entryType": "soft-navigation",
  "startTime": 2226.25,
  "duration": 42.25,
  "navigationId": 2463,
  "paintTime": 2232.5,
  "presentationTime": 2268.5,
  "navigationType": "push",
  "interactionId": 1704
}