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