Handle the initial login form presented to the user by the
relying party (consumer). This predicate discovers the OpenID
server, associates itself with this server and redirects the
user's browser to the OpenID server, providing the extra
openid.X name-value pairs. Options is, against the conventions,
placed in front of the Request to allow for smooth cooperation
with http_dispatch.pl. Options processes:
- return_to(+URL)
- Specifies where the OpenID provider should return to.
Normally, that is the current location.
- trust_root(+URL)
- Specifies the
openid.trust_root attribute. Defaults to
the root of the current server (i.e., http://host[.port]/).
- realm(+URL)
- Specifies the
openid.realm attribute. Default is the
trust_root.
- ax(+Spec)
- Request the exchange of additional attributes from the
identity provider. See http_ax_attributes/2 for details.
The OpenId server will redirect to the openid.return_to URL.
- throws
- -
http_reply(moved_temporary(Redirect))
