write-only
Sets the function to be called when a site is requesting
authentication. The URL requested and the security realm from the
server are passed in the arguments url
and realm
.
The function returns a Future
which should complete when the
authentication has been resolved. If credentials cannot be
provided the Future
should complete with false
. If
credentials are available the function should add these using
addCredentials
before completing the Future
with the value
true
.
If the Future
completes with true the request will be retried
using the updated credentials. Otherwise response processing will
continue normally.