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Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402]

   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  namespace mod_h5pactivity\xapi;
  18  
  19  use mod_h5pactivity\local\attempt;
  20  use mod_h5pactivity\local\manager;
  21  use mod_h5pactivity\event\statement_received;
  22  use core_xapi\local\statement;
  23  use core_xapi\handler as handler_base;
  24  use core\event\base as event_base;
  25  use core_xapi\local\state;
  26  use moodle_exception;
  27  
  28  defined('MOODLE_INTERNAL') || die();
  29  
  30  global $CFG;
  31  require_once($CFG->dirroot.'/mod/h5pactivity/lib.php');
  32  
  33  /**
  34   * Class xapi_handler for H5P statements and states.
  35   *
  36   * @package    mod_h5pactivity
  37   * @since      Moodle 3.9
  38   * @copyright  2020 Ferran Recio <ferran@moodle.com>
  39   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  40   */
  41  class handler extends handler_base {
  42  
  43      /**
  44       * Convert a statement object into a Moodle xAPI Event.
  45       *
  46       * If a statement is accepted by the xAPI webservice the component must provide
  47       * an event to handle that statement, otherwise the statement will be rejected.
  48       *
  49       * @param statement $statement
  50       * @return core\event\base|null a Moodle event to trigger
  51       */
  52      public function statement_to_event(statement $statement): ?event_base {
  53  
  54          // Only process statements with results.
  55          $xapiresult = $statement->get_result();
  56          if (empty($xapiresult)) {
  57              return null;
  58          }
  59  
  60          // Statements can contain any verb, for security reasons each
  61          // plugin needs to filter it's own specific verbs. For now the only verbs the H5P
  62          // plugin keeps track on are "answered" and "completed" because they are realted to grading.
  63          // In the future this list can be increased to track more user interactions.
  64          $validvalues = [
  65                  'http://adlnet.gov/expapi/verbs/answered',
  66                  'http://adlnet.gov/expapi/verbs/completed',
  67              ];
  68          $xapiverbid = $statement->get_verb_id();
  69          if (!in_array($xapiverbid, $validvalues)) {
  70              return null;
  71          }
  72  
  73          // Validate object.
  74          $xapiobject = $statement->get_activity_id();
  75  
  76          // H5P add some extra params to ID to define subcontents.
  77          $parts = explode('?', $xapiobject, 2);
  78          $contextid = array_shift($parts);
  79          $subcontent = str_replace('subContentId=', '', array_shift($parts) ?? '');
  80          if (empty($contextid) || !is_numeric($contextid)) {
  81              return null;
  82          }
  83          $context = \context::instance_by_id($contextid);
  84          if (!$context instanceof \context_module) {
  85              return null;
  86          }
  87  
  88          // As the activity does not accept group statement, the code can assume that the
  89          // statement user is valid (otherwise the xAPI library will reject the statement).
  90          $user = $statement->get_user();
  91          if (!has_capability('mod/h5pactivity:view', $context, $user)) {
  92              return null;
  93          }
  94  
  95          $cm = get_coursemodule_from_id('h5pactivity', $context->instanceid, 0, false);
  96          if (!$cm) {
  97              return null;
  98          }
  99  
 100          $manager = manager::create_from_coursemodule($cm);
 101  
 102          if (!$manager->is_tracking_enabled($user)) {
 103              return null;
 104          }
 105  
 106          // For now, attempts are only processed on a single batch starting with the final "completed"
 107          // and "answered" statements (this could change in the future). This initial statement have no
 108          // subcontent defined as they are the main finishing statement. For this reason, this statement
 109          // indicates a new attempt creation. This way, simpler H5P activies like multichoice can generate
 110          // an attempt each time the user answers while complex like question-set could group all questions
 111          // in a single attempt (using subcontents).
 112          if (empty($subcontent)) {
 113              $attempt = attempt::new_attempt($user, $cm);
 114          } else {
 115              $attempt = attempt::last_attempt($user, $cm);
 116          }
 117          if (!$attempt) {
 118              return null;
 119          }
 120          $result = $attempt->save_statement($statement, $subcontent);
 121          if (!$result) {
 122              return null;
 123          }
 124  
 125          // Update activity if necessary.
 126          if ($attempt->get_scoreupdated()) {
 127              $grader = $manager->get_grader();
 128              $grader->update_grades($user->id);
 129          }
 130  
 131          // Convert into a Moodle event.
 132          $minstatement = $statement->minify();
 133          $params = [
 134              'other' => $minstatement,
 135              'context' => $context,
 136              'objectid' => $cm->instance,
 137              'userid' => $user->id,
 138          ];
 139          return statement_received::create($params);
 140      }
 141  
 142      /**
 143       * Validate a xAPI state.
 144       *
 145       * Check if the state is valid for this handler.
 146       *
 147       * This method is used also for the state get requests so the validation
 148       * cannot rely on having state data.
 149       *
 150       * @param state $state
 151       * @return bool if the state is valid or not
 152       */
 153      protected function validate_state(state $state): bool {
 154          $xapiobject = $state->get_activity_id();
 155  
 156          // H5P add some extra params to ID to define subcontents.
 157          $parts = explode('?', $xapiobject, 2);
 158          $contextid = array_shift($parts);
 159          if (empty($contextid) || !is_numeric($contextid)) {
 160              return false;
 161          }
 162  
 163          try {
 164              $context = \context::instance_by_id($contextid);
 165              if (!$context instanceof \context_module) {
 166                  return false;
 167              }
 168          } catch (moodle_exception $exception) {
 169              return false;
 170          }
 171  
 172          $cm = get_coursemodule_from_id('h5pactivity', $context->instanceid, 0, false);
 173          if (!$cm) {
 174              return false;
 175          }
 176  
 177          // If tracking is not enabled, the state won't be considered valid.
 178          $manager = manager::create_from_coursemodule($cm);
 179          $user = $state->get_user();
 180          if (!$manager->is_tracking_enabled($user)) {
 181              return false;
 182          }
 183  
 184          return true;
 185      }
 186  }