AuthenticateCallback

The callback that is invoked when an HTTP request receives an authentication challenge and is unable to respond using cached credentials. You can use this method to handle "basic" or "digest" authentication.

The callback can be used to display a UI dialog to ask the user to enter the credentials (is not obligated).

Use the cancel method to reject the authentication request.

Use the authenticate method to provide the credentials. In case you provide the credentials, the callback will not be invoked again for the current domain.

If the callback throws an exception, the cancel method will be invoked.