Examples

Take a look at a few example scripts showing how to trigger HAR export on a page.

Get HAR Data

This script shows how to trigger HAR export and get JSON data back (no local file created).

var options = {
  token: "test",    // Value of the token in your preferences
  getData: true,    // True if you want to also get HAR data as a string in the callback
};

HAR.triggerExport(options).then(result => {
  console.log(result.data);
});

Save To File

This example shows how to trigger HAR export and save the log automatically in a local *.har file. The default target directory is <firefox-profile-dir>/har/logs. You can provide different directory path in devtools.netmonitor.har.defaultLogDir preference.

File name can use format string to have better control over the formatting of the generated file name.

var options = {
  token: "test",
  fileName: "my test har file %Y, %H:%M:%S"  // Name of the file with format string
};

HAR.triggerExport(options).then(result => {
  // The local file is available now
});

Get HAR When Page is Loaded

It's possible to handle an har-page-ready event that is fired when the page is ready (fully loaded). This event complements the existing DOMContenLoaded and onLoad. It's fired when the following conditions are true.