Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * LTI web service endpoints

 *

 * @package mod_lti

 * @copyright  Copyright (c) 2011 Moodlerooms Inc. (http://www.moodlerooms.com)

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 * @author     Chris Scribner

 */

define('NO_DEBUG_DISPLAY', true);

define('NO_MOODLE_COOKIES', true);

require_once(__DIR__ . "/../../config.php");

require_once($CFG->dirroot.'/mod/lti/locallib.php');

require_once($CFG->dirroot.'/mod/lti/servicelib.php');

// TODO: Switch to core oauthlib once implemented - MDL-30149.

use mod_lti\service_exception_handler;

use moodle\mod\lti as lti;

use ltiservice_basicoutcomes\local\service\basicoutcomes;

$rawbody = file_get_contents("php://input");

$logrequests  = lti_should_log_request($rawbody);

$errorhandler = new service_exception_handler($logrequests);

// Register our own error handler so we can always send valid XML response.

set_exception_handler(array($errorhandler, 'handle'));

if ($logrequests) {

    lti_log_request($rawbody);

}

$ok = true;

$type = null;

$toolproxy = false;

$consumerkey = lti\get_oauth_key_from_headers(null, array(basicoutcomes::SCOPE_BASIC_OUTCOMES));

if ($consumerkey === false) {

    throw new Exception('Missing or invalid consumer key or access token.');

} else if (is_string($consumerkey)) {

    $toolproxy = lti_get_tool_proxy_from_guid($consumerkey);

    if ($toolproxy !== false) {

        $secrets = array($toolproxy->secret);

    } else if (!empty($tool)) {

        $secrets = array($typeconfig['password']);

    } else {

        $secrets = lti_get_shared_secrets_by_key($consumerkey);

    }

    $sharedsecret = lti_verify_message($consumerkey, lti_get_shared_secrets_by_key($consumerkey), $rawbody);

    if ($sharedsecret === false) {

        throw new Exception('Message signature not valid');

    }

}

// TODO MDL-46023 Replace this code with a call to the new library.

$xml = simplexml_load_string($rawbody);

if (!$xml) {

    throw new Exception('Invalid XML content');

}

$body = $xml->imsx_POXBody;

foreach ($body->children() as $child) {

    $messagetype = $child->getName();

}

// We know more about the message, update error handler to send better errors.

$errorhandler->set_message_id(lti_parse_message_id($xml));

$errorhandler->set_message_type($messagetype);

switch ($messagetype) {

    case 'replaceResultRequest':

        $parsed = lti_parse_grade_replace_message($xml);

        $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));

        if (!lti_accepts_grades($ltiinstance)) {

            throw new Exception('Tool does not accept grades');

        }

        lti_verify_sourcedid($ltiinstance, $parsed);

        lti_set_session_user($parsed->userid);

        $gradestatus = lti_update_grade($ltiinstance, $parsed->userid, $parsed->launchid, $parsed->gradeval);

        if (!$gradestatus) {

            throw new Exception('Grade replace response');

        }

        $responsexml = lti_get_response_xml(

                'success',

                'Grade replace response',

                $parsed->messageid,

                'replaceResultResponse'

        );

        echo $responsexml->asXML();

        break;

    case 'readResultRequest':

        $parsed = lti_parse_grade_read_message($xml);

        $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));

        if (!lti_accepts_grades($ltiinstance)) {

            throw new Exception('Tool does not accept grades');

        }

        // Getting the grade requires the context is set.

        $context = context_course::instance($ltiinstance->course);

        $PAGE->set_context($context);

        lti_verify_sourcedid($ltiinstance, $parsed);

        $grade = lti_read_grade($ltiinstance, $parsed->userid);

        $responsexml = lti_get_response_xml(

                'success',  // Empty grade is also 'success'.

                'Result read',

                $parsed->messageid,

                'readResultResponse'

        );

        $node = $responsexml->imsx_POXBody->readResultResponse;

        $node = $node->addChild('result')->addChild('resultScore');

        $node->addChild('language', 'en');

        $node->addChild('textString', isset($grade) ? $grade : '');

        echo $responsexml->asXML();

        break;

    case 'deleteResultRequest':

        $parsed = lti_parse_grade_delete_message($xml);

        $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));

        if (!lti_accepts_grades($ltiinstance)) {

            throw new Exception('Tool does not accept grades');

        }

        lti_verify_sourcedid($ltiinstance, $parsed);

        lti_set_session_user($parsed->userid);

        $gradestatus = lti_delete_grade($ltiinstance, $parsed->userid);

        if (!$gradestatus) {

            throw new Exception('Grade delete request');

        }

        $responsexml = lti_get_response_xml(

                'success',

                'Grade delete request',

                $parsed->messageid,

                'deleteResultResponse'

        );

        echo $responsexml->asXML();

        break;

    default:

        // Fire an event if we get a web service request which we don't support directly.

        // This will allow others to extend the LTI services, which I expect to be a common

        // use case, at least until the spec matures.

        $data = new stdClass();

        $data->body = $rawbody;

        $data->xml = $xml;

        $data->messageid = lti_parse_message_id($xml);

        $data->messagetype = $messagetype;

        $data->consumerkey = $consumerkey;

        $data->sharedsecret = $sharedsecret;

        $eventdata = array();

        $eventdata['other'] = array();

        $eventdata['other']['messageid'] = $data->messageid;

        $eventdata['other']['messagetype'] = $messagetype;

        $eventdata['other']['consumerkey'] = $consumerkey;

        // Before firing the event, allow subplugins a chance to handle.

        if (lti_extend_lti_services($data)) {

            break;

        }

        // If an event handler handles the web service, it should set this global to true

        // So this code knows whether to send an "operation not supported" or not.

        global $ltiwebservicehandled;

        $ltiwebservicehandled = false;

        try {

            $event = \mod_lti\event\unknown_service_api_called::create($eventdata);

            $event->set_message_data($data);

            $event->trigger();

        } catch (Exception $e) {

            $ltiwebservicehandled = false;

        }

        if (!$ltiwebservicehandled) {

            $responsexml = lti_get_response_xml(

                'unsupported',

                'unsupported',

                 lti_parse_message_id($xml),

                 $messagetype

            );

            echo $responsexml->asXML();

        }

        break;

}