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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 core_xapi\external;
  18  
  19  use core_xapi\local\statement;
  20  use core_xapi\handler;
  21  use core_xapi\xapi_exception;
  22  use core_external\external_api;
  23  use core_external\external_function_parameters;
  24  use core_external\external_multiple_structure;
  25  use core_external\external_value;
  26  use core_component;
  27  
  28  /**
  29   * This is the external API for generic xAPI handling.
  30   *
  31   * @package    core_xapi
  32   * @since      Moodle 3.9
  33   * @copyright  2020 Ferran Recio
  34   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35   */
  36  class post_statement extends external_api {
  37  
  38      /**
  39       * Parameters for execute
  40       *
  41       * @return external_function_parameters
  42       */
  43      public static function execute_parameters() {
  44          return new external_function_parameters(
  45              [
  46                  'component' => new external_value(PARAM_COMPONENT, 'Component name', VALUE_REQUIRED),
  47                  'requestjson' => new external_value(PARAM_RAW, 'json object with all the statements to post', VALUE_REQUIRED)
  48              ]
  49          );
  50      }
  51  
  52      /**
  53       * Process a statement post request.
  54       *
  55       * @param string $component component name (frankenstyle)
  56       * @param string $requestjson json object with all the statements to post
  57       * @return bool[] storing acceptance of every statement
  58       */
  59      public static function execute(string $component, string $requestjson): array {
  60  
  61          $params = self::validate_parameters(self::execute_parameters(), array(
  62              'component' => $component,
  63              'requestjson' => $requestjson,
  64          ));
  65          $component = $params['component'];
  66          $requestjson = $params['requestjson'];
  67  
  68          static::validate_component($component);
  69  
  70          $handler = handler::create($component);
  71  
  72          $statements = self::get_statements_from_json($requestjson);
  73  
  74          if (!self::check_statements_users($statements, $handler)) {
  75              throw new xapi_exception('Statements actor is not the current user');
  76          }
  77  
  78          $result = $handler->process_statements($statements);
  79  
  80          // In case no statement is processed, an error must be returned.
  81          if (count(array_filter($result)) == 0) {
  82              throw new xapi_exception('No statement can be processed.');
  83          }
  84          return $result;
  85      }
  86  
  87      /**
  88       * Return for execute.
  89       */
  90      public static function execute_returns() {
  91          return new external_multiple_structure(
  92              new external_value(PARAM_BOOL, 'If the statement is accepted'),
  93              'List of statements storing acceptance results'
  94          );
  95      }
  96  
  97      /**
  98       * Check component name.
  99       *
 100       * Note: this function is separated mainly for testing purposes to
 101       * be overridden to fake components.
 102       *
 103       * @throws xapi_exception if component is not available
 104       * @param string $component component name
 105       */
 106      protected static function validate_component(string $component): void {
 107          // Check that $component is a real component name.
 108          $dir = core_component::get_component_directory($component);
 109          if (!$dir) {
 110              throw new xapi_exception("Component $component not available.");
 111          }
 112      }
 113  
 114      /**
 115       * Convert mulitple types of statement request into an array of statements.
 116       *
 117       * @throws xapi_exception if JSON cannot be parsed
 118       * @param string $requestjson json encoded statements structure
 119       * @return statement[] array of statements
 120       */
 121      private static function get_statements_from_json(string $requestjson): array {
 122          $request = json_decode($requestjson);
 123          if ($request === null) {
 124              throw new xapi_exception('JSON error: '.json_last_error_msg());
 125          }
 126          $result = [];
 127          if (is_array($request)) {
 128              foreach ($request as $data) {
 129                  $result[] = statement::create_from_data($data);
 130              }
 131          } else {
 132              $result[] = statement::create_from_data($request);
 133          }
 134          if (empty($result)) {
 135              throw new xapi_exception('No statements detected');
 136          }
 137          return $result;
 138      }
 139  
 140      /**
 141       * Check that $USER is actor in all statements.
 142       *
 143       * @param statement[] $statements array of statements
 144       * @param handler $handler specific xAPI handler
 145       * @return bool if $USER is actor in all statements
 146       */
 147      private static function check_statements_users(array $statements, handler $handler): bool {
 148          global $USER;
 149  
 150          foreach ($statements as $statement) {
 151              if ($handler->supports_group_actors()) {
 152                  $users = $statement->get_all_users();
 153                  if (!isset($users[$USER->id])) {
 154                      return false;
 155                  }
 156              } else {
 157                  $user = $statement->get_user();
 158                  if ($user->id != $USER->id) {
 159                      return false;
 160                  }
 161              }
 162          }
 163          return true;
 164      }
 165  }