authenticate property Null safety
Sets the function to be called when a site is requesting authentication.
The URL requested, the authentication scheme and the security realm
from the server are passed in the arguments url
, scheme
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, however, the retried request will not
carry the original request payload. Otherwise response processing will
continue normally.
If it is known that the remote server requires authentication for all
requests, it is advisable to use addCredentials directly, or manually
set the 'authorization'
header on the request to avoid the overhead
of a failed request, or issues due to missing request payload on retried
request.
Implementation
void set authenticate(Future<bool> f(Uri url, String scheme, String? realm)?);