3.11 library(http/http_openid): OpenID consumer and server library
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Availability::- use_module(library(http/http_openid)).
Source[det]openid_user(+Request:http_request, -OpenID:url, +Options)
True if OpenID is a validated OpenID associated with the current session. The scenario for which this predicate is designed is to allow an HTTP handler that requires a valid login to use the transparent code below. 
handler(Request) :-
      openid_user(Request, OpenID, []),
      ...

If the user is not yet logged on a sequence of redirects will follow:

  1. Show a page for login (default: page /openid/login), predicate reply_openid_login/1)
  2. By default, the OpenID login page is a form that is submitted to the verify, which calls openid_verify/2.
  3. openid_verify/2 does the following:

    • Find the OpenID claimed identity and server
    • Associate to the OpenID server
    • redirects to the OpenID server for validation

  4. The OpenID server will redirect here with the authentication information. This is handled by openid_authenticate/4.

Options:

login_url(Login)
(Local) URL of page to enter OpenID information. Default is the handler for openid_login_page/1
See also
openid_authenticate/4 produces errors if login is invalid or cancelled.