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
  21  * @subpackage lti
  22  * @copyright  Copyright (c) 2011 Moodlerooms Inc. (http://www.moodlerooms.com)
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  * @author     Chris Scribner
  25  */
  26
  27 require_once(dirname(__FILE__) . "/../../config.php");
  28 require_once($CFG->dirroot.'/mod/lti/locallib.php');
  29 require_once($CFG->dirroot.'/mod/lti/servicelib.php');
  30
  31 // TODO: Switch to core oauthlib once implemented - MDL-30149
  32 use moodle\mod\lti as lti;
  33
  34 $rawbody = file_get_contents("php://input");
  35
  36 foreach (getallheaders() as $name => $value) {
  37     if ($name === 'Authorization') {
  38         // TODO: Switch to core oauthlib once implemented - MDL-30149
  39         $oauthparams = lti\OAuthUtil::split_header($value);
  40
  41         $consumerkey = $oauthparams['oauth_consumer_key'];
  42         break;
  43     }
  44 }
  45
  46 if (empty($consumerkey)) {
  47     throw new Exception('Consumer key is missing.');
  48 }
  49
  50 $sharedsecret = lti_verify_message($consumerkey, lti_get_shared_secrets_by_key($consumerkey), $rawbody);
  51
  52 if ($sharedsecret === false) {
  53     throw new Exception('Message signature not valid');
  54 }
  55
  56 $xml = new SimpleXMLElement($rawbody);
  57
  58 $body = $xml->imsx_POXBody;
  59 foreach ($body->children() as $child) {
  60     $messagetype = $child->getName();
  61 }
  62
  63 switch ($messagetype) {
  64     case 'replaceResultRequest':
  65         try {
  66             $parsed = lti_parse_grade_replace_message($xml);
  67         } catch (Exception $e) {
  68             $responsexml = lti_get_response_xml(
  69                 'failure',
  70                 $e->getMessage(),
  71                 uniqid(),
  72                 'replaceResultResponse');
  73
  74             echo $responsexml->asXML();
  75             break;
  76         }
  77
  78         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
  79
  80         lti_verify_sourcedid($ltiinstance, $parsed);
  81
  82         $gradestatus = lti_update_grade($ltiinstance, $parsed->userid, $parsed->launchid, $parsed->gradeval);
  83
  84         $responsexml = lti_get_response_xml(
  85                 $gradestatus ? 'success' : 'failure',
  86                 'Grade replace response',
  87                 $parsed->messageid,
  88                 'replaceResultResponse'
  89         );
  90
  91         echo $responsexml->asXML();
  92
  93         break;
  94
  95     case 'readResultRequest':
  96         $parsed = lti_parse_grade_read_message($xml);
  97
  98         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
  99
 100         //Getting the grade requires the context is set
 101         $context = get_context_instance(CONTEXT_COURSE, $ltiinstance->course);
 102         $PAGE->set_context($context);
 103
 104         lti_verify_sourcedid($ltiinstance, $parsed);
 105
 106         $grade = lti_read_grade($ltiinstance, $parsed->userid);
 107
 108         $responsexml = lti_get_response_xml(
 109                 isset($grade) ? 'success' : 'failure',
 110                 'Result read',
 111                 $parsed->messageid,
 112                 'readResultResponse'
 113         );
 114
 115         $node = $responsexml->imsx_POXBody->readResultResponse;
 116         $node = $node->addChild('result')->addChild('resultScore');
 117         $node->addChild('language', 'en');
 118         $node->addChild('textString', isset($grade) ? $grade : '');
 119
 120         echo $responsexml->asXML();
 121
 122         break;
 123
 124     case 'deleteResultRequest':
 125         $parsed = lti_parse_grade_delete_message($xml);
 126
 127         $ltiinstance = $DB->get_record('lti', array('id' => $parsed->instanceid));
 128
 129         lti_verify_sourcedid($ltiinstance, $parsed);
 130
 131         $gradestatus = lti_delete_grade($ltiinstance, $parsed->userid);
 132
 133         $responsexml = lti_get_response_xml(
 134                 $gradestatus ? 'success' : 'failure',
 135                 'Grade delete request',
 136                 $parsed->messageid,
 137                 'deleteResultResponse'
 138         );
 139
 140         echo $responsexml->asXML();
 141
 142         break;
 143
 144     default:
 145         //Fire an event if we get a web service request which we don't support directly.
 146         //This will allow others to extend the LTI services, which I expect to be a common
 147         //use case, at least until the spec matures.
 148         $data = new stdClass();
 149         $data->body = $rawbody;
 150         $data->xml = $xml;
 151         $data->messagetype = $messagetype;
 152         $data->consumerkey = $consumerkey;
 153         $data->sharedsecret = $sharedsecret;
 154
 155         //If an event handler handles the web service, it should set this global to true
 156         //So this code knows whether to send an "operation not supported" or not.
 157         global $lti_web_service_handled;
 158         $lti_web_service_handled = false;
 159
 160         events_trigger('lti_unknown_service_api_call', $data);
 161
 162         if (!$lti_web_service_handled) {
 163             $responsexml = lti_get_response_xml(
 164                 'unsupported',
 165                 'unsupported',
 166                  lti_parse_message_id($xml),
 167                  $messagetype
 168             );
 169
 170             echo $responsexml->asXML();
 171         }
 172
 173         break;
 174 }
 175
 176
 177 //echo print_r(apache_request_headers(), true);
 178
 179 //echo '<br />';
 180
 181 //echo file_get_contents("php://input");