Webservice protocols

Note: This page is a work-in-progress. Comments and suggestions are welcome! Please use the page comments.

Introduction

Web service protocol plugins are web service servers. These servers let external applications call Moodle web service functions in an specific protocol: REST / AMF / SOAP /XML-RPC / ...

Examples

The easiest example is the REST server.

File structure

in webservice/myprotocol/server.php <?php /**

* myprotocol web service entry point. The authentication is done via tokens.
*
* @package    webservice_myprotocol
* @copyright  20XX Your Name
* @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/

/**

* NO_DEBUG_DISPLAY - disable moodle specific debug messages and any errors in output
*/

define('NO_DEBUG_DISPLAY', true);

/**

* NO_MOODLE_COOKIES - no cookies with web service
*/

define('NO_MOODLE_COOKIES', true);

require('../../config.php'); require_once("$CFG->dirroot/webservice/myprotocol/locallib.php");

if (!webservice_protocol_is_enabled('myprotocol')) {

   die;

}

$server = new webservice_rest_server(WEBSERVICE_AUTHMETHOD_PERMANENT_TOKEN); $server->run(); die;

in webservice/myprotocol/locallib.php

<?php

/**

* myprotocol web service implementation classes and methods.
*
* @package    webservice_myprotocol
* @copyright  20XX Your Name
* @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/

require_once("$CFG->dirroot/webservice/lib.php");

/**

* myprotocol service server implementation.
*
* @package    webservice_myprotocol
* @copyright  20XX Your Name
* @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/

class webservice_myprotocol_server extends webservice_base_server {

   /**
    * Contructor
    *
    * @param string $authmethod authentication method of the web service (WEBSERVICE_AUTHMETHOD_PERMANENT_TOKEN, ...)
    */
   public function __construct($authmethod) {
       parent::__construct($authmethod);
   }

   /**
    * This method parses the $_REQUEST
    */
   protected function parse_request() {
      //Retrieve the user credentials (token / ...), the web service function parameters, ...
      $this->token = isset($_REQUEST['wstoken']) ? $_REQUEST['wstoken'] : null;
      unset($_REQUEST['wstoken']);

      $this->functionname = isset($_REQUEST['wsfunction']) ? $_REQUEST['wsfunction'] : null;
      unset($_REQUEST['wsfunction']);

      $this->parameters = $_REQUEST;
   }

   /**
    * Send the result of function call to the WS client
    */
   protected function send_response() {

       // Check that the returned values are valid
       // sometimes it is not necessary like for Zend servers where 
       // the cleaning is done in service_class_method_body() of the webservice_zend_server class
       try {
           $validatedvalues = external_api::clean_returnvalue($this->function->returns_desc, $this->returns);
       } catch (Exception $ex) {
           $exception = $ex;
       }

       //PROCESS THE RESPONSE
       echo $response;
   }

   /**
    * Send the error information to the WS client
    * @param exception $ex the exception that we are sending
    */
   protected function send_error($ex=null) {
       //PROCESS THE ERROR MESSAGE
       echo $error;
   }

}

Database tables

describe all the tables that must be implemented describe how to store addtional data

TODO

• Link your pages to type in Frankenstyle page
• Link your pages to type in Plugins page
• Add pages to Plugins category
• This should be done for following plugin's: https://docs.moodle.org/dev/Frankenstyle#Plugin_types