mod/lti/service.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * LTI web service endpoints
  19  *
  20  * @package mod_lti
  21  * @copyright  Copyright (c) 2011 Moodlerooms Inc. (http://www.moodlerooms.com)
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  * @author     Chris Scribner
  24  */
  25
  26 define('NO_DEBUG_DISPLAY', true);
  27
  28 require_once(dirname(__FILE__) . "/../../config.php");
  29 require_once($CFG->dirroot.'/mod/lti/locallib.php');
  30 require_once($CFG->dirroot.'/mod/lti/servicelib.php');
  31
  32 // TODO: Switch to core oauthlib once implemented - MDL-30149
  33 use moodle\mod\lti as lti;
  34
  35 $rawbody = file_get_contents("php://input");
  36
  37 foreach (lti\OAuthUtil::get_headers() as $name => $value) {
  38     if ($name === 'Authorization') {
  39         // TODO: Switch to core oauthlib once implemented - MDL-30149
  40         $oauthparams = lti\OAuthUtil::split_header($value);
  41
  42         $consumerkey = $oauthparams['oauth_consumer_key'];
  43         break;
  44     }
  45 }
  46
  47 if (empty($consumerkey)) {
  48     throw new Exception('Consumer key is missing.');
  49 }
  50
  51 $sharedsecret = lti_verify_message($consumerkey, lti_get_shared_secrets_by_key($consumerkey), $rawbody);
  52
  53 if ($sharedsecret === false) {
  54     throw new Exception('Message signature not valid');
  55 }
  56
  57 $xml = new SimpleXMLElement($rawbody);
  58
  59 $body = $xml->imsx_POXBody;
  60 foreach ($body->children() as $child) {
  61     $messagetype = $child->getName();
  62 }
  63
  64 switch ($messagetype) {
  65     case 'replaceResultRequest':
  66         try {
  67             $parsed = lti_parse_grade_replace_message($xml);
  68         } catch (Exception $e) {
  69             $responsexml = lti_get_response_xml(
  70                 'failure',
  71                 $e->getMessage(),
  72                 uniqid(),
  73                 'replaceResultResponse');
  74
  75             echo $responsexml->asXML();
  76             break;
  77         }
  78
  79         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
  80
  81         lti_verify_sourcedid($ltiinstance, $parsed);
  82
  83         $gradestatus = lti_update_grade($ltiinstance, $parsed->userid, $parsed->launchid, $parsed->gradeval);
  84
  85         $responsexml = lti_get_response_xml(
  86                 $gradestatus ? 'success' : 'failure',
  87                 'Grade replace response',
  88                 $parsed->messageid,
  89                 'replaceResultResponse'
  90         );
  91
  92         echo $responsexml->asXML();
  93
  94         break;
  95
  96     case 'readResultRequest':
  97         $parsed = lti_parse_grade_read_message($xml);
  98
  99         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
 100
 101         //Getting the grade requires the context is set
 102         $context = context_course::instance($ltiinstance->course);
 103         $PAGE->set_context($context);
 104
 105         lti_verify_sourcedid($ltiinstance, $parsed);
 106
 107         $grade = lti_read_grade($ltiinstance, $parsed->userid);
 108
 109         $responsexml = lti_get_response_xml(
 110                 'success',  // Empty grade is also 'success'
 111                 'Result read',
 112                 $parsed->messageid,
 113                 'readResultResponse'
 114         );
 115
 116         $node = $responsexml->imsx_POXBody->readResultResponse;
 117         $node = $node->addChild('result')->addChild('resultScore');
 118         $node->addChild('language', 'en');
 119         $node->addChild('textString', isset($grade) ? $grade : '');
 120
 121         echo $responsexml->asXML();
 122
 123         break;
 124
 125     case 'deleteResultRequest':
 126         $parsed = lti_parse_grade_delete_message($xml);
 127
 128         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
 129
 130         lti_verify_sourcedid($ltiinstance, $parsed);
 131
 132         $gradestatus = lti_delete_grade($ltiinstance, $parsed->userid);
 133
 134         $responsexml = lti_get_response_xml(
 135                 $gradestatus ? 'success' : 'failure',
 136                 'Grade delete request',
 137                 $parsed->messageid,
 138                 'deleteResultResponse'
 139         );
 140
 141         echo $responsexml->asXML();
 142
 143         break;
 144
 145     default:
 146         //Fire an event if we get a web service request which we don't support directly.
 147         //This will allow others to extend the LTI services, which I expect to be a common
 148         //use case, at least until the spec matures.
 149         $data = new stdClass();
 150         $data->body = $rawbody;
 151         $data->xml = $xml;
 152         $data->messagetype = $messagetype;
 153         $data->consumerkey = $consumerkey;
 154         $data->sharedsecret = $sharedsecret;
 155         $eventdata = array();
 156         $eventdata['other'] = array();
 157         $eventdata['other']['messageid'] = lti_parse_message_id($xml);
 158         $eventdata['other']['messagetype'] = $messagetype;
 159         $eventdata['other']['consumerkey'] = $consumerkey;
 160
 161         // Before firing the event, allow subplugins a chance to handle.
 162         if (lti_extend_lti_services((object) $eventdata['other'])) {
 163             break;
 164         }
 165
 166         //If an event handler handles the web service, it should set this global to true
 167         //So this code knows whether to send an "operation not supported" or not.
 168         global $lti_web_service_handled;
 169         $lti_web_service_handled = false;
 170
 171         try {
 172             $event = \mod_lti\event\unknown_service_api_called::create($eventdata);
 173             $event->set_message_data($data);
 174             $event->trigger();
 175         } catch (Exception $e) {
 176             $lti_web_service_handled = false;
 177         }
 178
 179         if (!$lti_web_service_handled) {
 180             $responsexml = lti_get_response_xml(
 181                 'unsupported',
 182                 'unsupported',
 183                  lti_parse_message_id($xml),
 184                  $messagetype
 185             );
 186
 187             echo $responsexml->asXML();
 188         }
 189
 190         break;
 191 }
 192
 193
 194 //echo print_r(apache_request_headers(), true);
 195
 196 //echo '<br />';
 197
 198 //echo file_get_contents("php://input");