1<?php
2
3/**
4 * An interface for OpenID extensions.
5 *
6 * @package OpenID
7 */
8
9/**
10 * Require the Message implementation.
11 */
12require_once 'Auth/OpenID/Message.php';
13
14/**
15 * A base class for accessing extension request and response data for
16 * the OpenID 2 protocol.
17 *
18 * @package OpenID
19 */
20class Auth_OpenID_Extension {
21    /**
22     * ns_uri: The namespace to which to add the arguments for this
23     * extension
24     */
25    var $ns_uri = null;
26    var $ns_alias = null;
27
28    /**
29     * Get the string arguments that should be added to an OpenID
30     * message for this extension.
31     */
32    function getExtensionArgs()
33    {
34        return null;
35    }
36
37    /**
38     * Add the arguments from this extension to the provided message.
39     *
40     * Returns the message with the extension arguments added.
41     */
42    function toMessage($message)
43    {
44        $implicit = $message->isOpenID1();
45        $added = $message->namespaces->addAlias($this->ns_uri,
46                                                $this->ns_alias,
47                                                $implicit);
48
49        if ($added === null) {
50            if ($message->namespaces->getAlias($this->ns_uri) !=
51                $this->ns_alias) {
52                return null;
53            }
54        }
55
56        $message->updateArgs($this->ns_uri,
57                             $this->getExtensionArgs());
58        return $message;
59    }
60}
61
62