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Differences Between: [Versions 310 and 401] [Versions 311 and 401] [Versions 39 and 401] [Versions 401 and 402] [Versions 401 and 403]

   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  /**
  19   * REST web service implementation classes and methods.
  20   *
  21   * @package    webservice_rest
  22   * @copyright  2009 Jerome Mouneyrac
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  require_once("$CFG->dirroot/webservice/lib.php");
  27  
  28  /**
  29   * REST service server implementation.
  30   *
  31   * @package    webservice_rest
  32   * @copyright  2009 Petr Skoda (skodak)
  33   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  34   */
  35  class webservice_rest_server extends webservice_base_server {
  36  
  37      /** @var string return method ('xml' or 'json') */
  38      protected $restformat;
  39  
  40      /**
  41       * Contructor
  42       *
  43       * @param string $authmethod authentication method of the web service (WEBSERVICE_AUTHMETHOD_PERMANENT_TOKEN, ...)
  44       * @param string $restformat Format of the return values: 'xml' or 'json'
  45       */
  46      public function __construct($authmethod) {
  47          parent::__construct($authmethod);
  48          $this->wsname = 'rest';
  49      }
  50  
  51      /**
  52       * Set the request format to.
  53       */
  54      public function set_rest_format(): void {
  55          // Get GET and POST parameters.
  56          $methodvariables = array_merge($_GET, $_POST);
  57  
  58          // Retrieve REST format parameter - 'xml' (default) or 'json'.
  59          $restformatisset = isset($methodvariables['moodlewsrestformat'])
  60                  && (($methodvariables['moodlewsrestformat'] == 'xml' || $methodvariables['moodlewsrestformat'] == 'json'));
  61          $this->restformat = $restformatisset ? $methodvariables['moodlewsrestformat'] : 'xml';
  62      }
  63  
  64      /**
  65       * This method parses the $_POST and $_GET superglobals and looks for
  66       * the following information:
  67       *  1/ user authentication - username+password or token (wsusername, wspassword and wstoken parameters)
  68       *  2/ function name (wsfunction parameter)
  69       *  3/ function parameters (all other parameters except those above)
  70       *  4/ text format parameters
  71       *  5/ return rest format xml/json
  72       */
  73      protected function parse_request() {
  74  
  75          // Retrieve and clean the POST/GET parameters from the parameters specific to the server.
  76          parent::set_web_service_call_settings();
  77  
  78          // Get GET and POST parameters.
  79          $methodvariables = array_merge($_GET, $_POST);
  80          $this->set_rest_format();
  81          unset($methodvariables['moodlewsrestformat']);
  82  
  83          if ($this->authmethod == WEBSERVICE_AUTHMETHOD_USERNAME) {
  84              $this->username = isset($methodvariables['wsusername']) ? $methodvariables['wsusername'] : null;
  85              unset($methodvariables['wsusername']);
  86  
  87              $this->password = isset($methodvariables['wspassword']) ? $methodvariables['wspassword'] : null;
  88              unset($methodvariables['wspassword']);
  89  
  90              $this->functionname = isset($methodvariables['wsfunction']) ? $methodvariables['wsfunction'] : null;
  91              unset($methodvariables['wsfunction']);
  92  
  93              $this->parameters = $methodvariables;
  94  
  95          } else {
  96              $this->token = isset($methodvariables['wstoken']) ? $methodvariables['wstoken'] : null;
  97              unset($methodvariables['wstoken']);
  98  
  99              $this->functionname = isset($methodvariables['wsfunction']) ? $methodvariables['wsfunction'] : null;
 100              unset($methodvariables['wsfunction']);
 101  
 102              $this->parameters = $methodvariables;
 103          }
 104      }
 105  
 106      /**
 107       * Send the result of function call to the WS client
 108       * formatted as XML document.
 109       */
 110      protected function send_response() {
 111  
 112          //Check that the returned values are valid
 113          try {
 114              if ($this->function->returns_desc != null) {
 115                  $validatedvalues = external_api::clean_returnvalue($this->function->returns_desc, $this->returns);
 116              } else {
 117                  $validatedvalues = null;
 118              }
 119          } catch (Exception $ex) {
 120              $exception = $ex;
 121          }
 122  
 123          if (!empty($exception)) {
 124              $response =  $this->generate_error($exception);
 125          } else {
 126              //We can now convert the response to the requested REST format
 127              if ($this->restformat == 'json') {
 128                  $response = json_encode($validatedvalues);
 129              } else {
 130                  $response = '<?xml version="1.0" encoding="UTF-8" ?>'."\n";
 131                  $response .= '<RESPONSE>'."\n";
 132                  $response .= self::xmlize_result($validatedvalues, $this->function->returns_desc);
 133                  $response .= '</RESPONSE>'."\n";
 134              }
 135          }
 136  
 137          $this->send_headers();
 138          echo $response;
 139      }
 140  
 141      /**
 142       * Send the error information to the WS client
 143       * formatted as XML document.
 144       * Note: the exception is never passed as null,
 145       *       it only matches the abstract function declaration.
 146       * @param exception $ex the exception that we are sending
 147       */
 148      protected function send_error($ex=null) {
 149          // Unless debugging is completely off, log the error to server error log.
 150          if (debugging('', DEBUG_MINIMAL)) {
 151              $info = get_exception_info($ex);
 152              // This format is the same as default_exception_handler() in setuplib.php but with the
 153              // word 'REST' instead of 'Default', to make it easy to reuse any existing processing.
 154              error_log('REST exception handler: ' . $info->message . ' Debug: ' .
 155                      $info->debuginfo . "\n" . format_backtrace($info->backtrace, true));
 156          }
 157  
 158          $this->send_headers();
 159          echo $this->generate_error($ex);
 160      }
 161  
 162      /**
 163       * Build the error information matching the REST returned value format (JSON or XML)
 164       * @param exception $ex the exception we are converting in the server rest format
 165       * @return string the error in the requested REST format
 166       */
 167      protected function generate_error($ex) {
 168          if ($this->restformat == 'json') {
 169              $errorobject = new stdClass;
 170              $errorobject->exception = get_class($ex);
 171              if (isset($ex->errorcode)) {
 172                  $errorobject->errorcode = $ex->errorcode;
 173              }
 174              $errorobject->message = $ex->getMessage();
 175              if (debugging() and isset($ex->debuginfo)) {
 176                  $errorobject->debuginfo = $ex->debuginfo;
 177              }
 178              $error = json_encode($errorobject);
 179          } else {
 180              $error = '<?xml version="1.0" encoding="UTF-8" ?>'."\n";
 181              $error .= '<EXCEPTION class="'.get_class($ex).'">'."\n";
 182              if (isset($ex->errorcode)) {
 183                  $error .= '<ERRORCODE>' . htmlspecialchars($ex->errorcode, ENT_COMPAT, 'UTF-8')
 184                          . '</ERRORCODE>' . "\n";
 185              }
 186              $error .= '<MESSAGE>'.htmlspecialchars($ex->getMessage(), ENT_COMPAT, 'UTF-8').'</MESSAGE>'."\n";
 187              if (debugging() and isset($ex->debuginfo)) {
 188                  $error .= '<DEBUGINFO>'.htmlspecialchars($ex->debuginfo, ENT_COMPAT, 'UTF-8').'</DEBUGINFO>'."\n";
 189              }
 190              $error .= '</EXCEPTION>'."\n";
 191          }
 192          return $error;
 193      }
 194  
 195      /**
 196       * Internal implementation - sending of page headers.
 197       */
 198      protected function send_headers() {
 199          if ($this->restformat == 'json') {
 200              header('Content-type: application/json');
 201          } else {
 202              header('Content-Type: application/xml; charset=utf-8');
 203              header('Content-Disposition: inline; filename="response.xml"');
 204          }
 205          header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
 206          header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 207          header('Pragma: no-cache');
 208          header('Accept-Ranges: none');
 209          // Allow cross-origin requests only for Web Services.
 210          // This allow to receive requests done by Web Workers or webapps in different domains.
 211          header('Access-Control-Allow-Origin: *');
 212      }
 213  
 214      /**
 215       * Internal implementation - recursive function producing XML markup.
 216       *
 217       * @param mixed $returns the returned values
 218       * @param external_description $desc
 219       * @return string
 220       */
 221      protected static function xmlize_result($returns, $desc) {
 222          if ($desc === null) {
 223              return '';
 224  
 225          } else if ($desc instanceof external_value) {
 226              if (is_bool($returns)) {
 227                  // we want 1/0 instead of true/false here
 228                  $returns = (int)$returns;
 229              }
 230              if (is_null($returns)) {
 231                  return '<VALUE null="null"/>'."\n";
 232              } else {
 233                  return '<VALUE>'.htmlspecialchars($returns, ENT_COMPAT, 'UTF-8').'</VALUE>'."\n";
 234              }
 235  
 236          } else if ($desc instanceof external_multiple_structure) {
 237              $mult = '<MULTIPLE>'."\n";
 238              if (!empty($returns)) {
 239                  foreach ($returns as $val) {
 240                      $mult .= self::xmlize_result($val, $desc->content);
 241                  }
 242              }
 243              $mult .= '</MULTIPLE>'."\n";
 244              return $mult;
 245  
 246          } else if ($desc instanceof external_single_structure) {
 247              $single = '<SINGLE>'."\n";
 248              foreach ($desc->keys as $key=>$subdesc) {
 249                  $value = isset($returns[$key]) ? $returns[$key] : null;
 250                  $single .= '<KEY name="'.$key.'">'.self::xmlize_result($value, $subdesc).'</KEY>'."\n";
 251              }
 252              $single .= '</SINGLE>'."\n";
 253              return $single;
 254          }
 255      }
 256  }
 257  
 258  
 259  /**
 260   * REST test client class
 261   *
 262   * @package    webservice_rest
 263   * @copyright  2009 Petr Skoda (skodak)
 264   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 265   */
 266  class webservice_rest_test_client implements webservice_test_client_interface {
 267      /**
 268       * Execute test client WS request
 269       * @param string $serverurl server url (including token parameter or username/password parameters)
 270       * @param string $function function name
 271       * @param array $params parameters of the called function
 272       * @return mixed
 273       */
 274      public function simpletest($serverurl, $function, $params) {
 275          return download_file_content($serverurl.'&wsfunction='.$function, null, $params);
 276      }
 277  }