PasswordCredential.additionalData

The additionalData property of the PasswordCredential interface takes one of a FormData instance, a URLSearchParams instance, or null. The data in the objects will be added to the request body and sent to the remote endpoint with the credentials.

Syntax

passwordCredential.additionalData = formData
formData = passwordCredential.additionalData
passwordCredential.additionalData = urlSearchParams
ulrSearchParams = passwordCredential.additionalData

Value

One of a FormData instance, a URLSearchParams instance, or null.

Example

The following example creates a FormData object with an appended CSRF token. It then stores the form object in the additionalData parameter, before sending it to server in a call to fetch.

//The options object was previously created.
navigator.credentials.get(options).then(function(creds) {
  if (creds.type == 'password') {
    var form = new FormData();
    var csrf_token = document.querySelector('csrf_token').value;
    form.append('csrf_token', csrf_token);

    creds.additionalData = form;

    fetch('https://www.example.com', {
      method: 'POST',
      credentials: creds
    });
  };
});

Specifications

Browser compatibility