MNet API

Introduction

This page aims to serve as the location for documenting the Moodle NETwork API (MNET API), both the XMLRPC functions and the associated code.

It is a work in progress, please add to it as you discover undocumented code.

How to use MNET

This paragraph will explain you how to setup a connection between a client and a server with mnet. It will also explain where to write the functions you want to call in the server.

Note: The following code is just here to give you a better idea of how the API works. Do not expect them to work as provided.

Basic Client/Server code

In this example we'll ask the server which methods we can access. The system server methods 'ListMethods' is already implemented, so we will only write client code:

   require_once($CFG->dirroot . '/mnet/xmlrpc/client.php'); //mnet client library

   /// Setup MNET environment
       global $MNET;
       if (empty($MNET)) {
           $MNET = new mnet_environment();
           $MNET->init();
       }             
  
   /// Setup the server
       $host = $DB->get_record('mnet_host',array('id' => 4)); //we retrieve the server(host) from the 'mnet_host' table
       $mnet_peer = new mnet_peer();                          //we create a new mnet_peer (server/host)
       $mnet_peer->set_wwwroot($host->wwwroot);               //we set this mnet_peer with the host http address

   /// Connect to the remote moodle and retrieve the list of methods (synchronous transmission)
       $client = new mnet_xmlrpc_client();        //create a new client
       $client->set_method('system/listMethods'); //tell it which method we're going to call       
       $client->send($mnet_peer);                 //Call the server
       $response = $client->response;             //Receive the server response 

       var_dump($response);

System methods

System methods are declared as available into /mnet/xmlrpc/client.php::permission_to_call(). If you add a new system method you will have to add its name to the system_methods array into this function.

A mnet server comes with few system methods which have been implemented into /mnet/xmlrpc/server.php::mnet_system()
Parameters are saved into the $params array. Your first $client->add_param($param1) we'll be in $params[0] etc.

Specific methods

Most of the time you don't want to add a system method but a method for a module/service. You also want it to be displayed by the "ListMethods" system method.

Let's implement a function returning "Hello World".

1. We create this function into servicefolder/services.php:

class services {

    function static helloWorld($firstname, $surname) {
        return "Hello World" . $firstname . $surname; //note that we could return an array, 
                                                      //it would still be managed by mnet without a change anywhere else
    }

}

2. We register this function as a mnet function into the database:
Into admin/mnet/adminlib.php, we add this code:

function mnet_get_functions($type, $parentname) {
...
else if ('service' == $type) {
/// we're going to load the service object (after having checked it exists) 
/// and call mnet_publishes function
$docname = 'services.php';
$relname = '/servicefolder/'. $docname;
$filename = $CFG->dirroot.$relname;
if (file_exists($filename)) include_once $filename;
$class = "services";
if (class_exists($class)) {
    $object = new $class(); 
    if (method_exists($object, 'mnet_publishes')) {
        (array)$publishes = $object->mnet_publishes(); //retrieve the service information
    }
}
}
... 
///below, the retrieved information are saved into the database

function upgrade_RPC_functions($returnurl) {
    ...
    /// check other mnet_get_functions calls into the same file
    mnet_get_functions('service', null);
}
*/

Into the Service class of servicefolder/services.php, add

public static function mnet_publishes() {
    $service= array();
    $service['name']        = 'service'; // Name & Description go in lang file
    $service['apiversion']  = 1;
    $service['methods']     = array('helloWorld');

    return array($service);
}

3. The server needs to dispatch in mnet/xmlrpc/server.php::mnet_server_dispatch(), we need to add:

else if ($callstack[0] == 'servicefolder') {    
        list($base, $filename, $methodname) = $callstack;  // Break out the callstack into its elements
        if ($filename == 'services.php') {   
            $response = mnet_server_invoke_method('/servicefolder/services.php', $methodname, $method, $payload, 'services');
            $response = mnet_server_prepare_response($response);
            echo $response;
        } else {
        /// Generate error response - unable to locate function
            exit(mnet_server_fault(7012, 'nosuchfunction'));
        }
}

4. We add the method to the "ListMethods" system method
No code is needed. Just go into the Moodle Administration > Networking > Peers. Select the Services tab from the host server. There, activate your service.

5. We write some client code
First of all test the code from the section "Client/Server" above. You should see "servicefolder/services.php/helloworld" function into the response.

We can now call this method. Change:

$client->set_method('system/listMethods');

For:

$client->set_method('servicefolder/services.php/helloworld');
$client->add_param('Thierry'); 
$client->add_param('Henry');

Entry points/XMLRPC documentation

The entry point is wwwroot/xmlrpc/server.php, which at some point calls mnet_permit_rpc_call, which sets some member variables in the MNET_REMOTE_CLIENT object (mnet/remote_client.php) so that later when mnet_server_dummy_method is called, it can dispatch the call accordingly. I think mnet_server_dummy_method is the only way functions get called.

Currently you can call class methods, static methods and functions. However, for a class method, there is currently only support to construct the object with no constructor arguments.

Authentication Functions

Documentation TODO

Enrolment Functions

Documentation TODO

Repository Functions

Documentation TODO

Portfolio Functions

send_content_intent

• Defined in: portfolio/type/mahara/lib.php
• Implemented in: Mahara. Moodle has this function but it is not an xmlrpc function, only a helper function to call the xmlrpc function in Mahara. (See MDL-16269)
• Parameters:
  • username: username of user to find or create
• Returns: Stdclass object with keys:
  • sendtype: string - either 'queue' or 'immediate' depending on what the remote system has decided
  • token: string - to use for all further communication

send_content_ready

• Defined in: portfolio/type/mahara/lib.php
• Implemented in: Mahara. Moodle has this function but it is not an xmlrpc function, only a helper function to call the xmlrpc function in Mahara. (See MDL-16269)
• Parameters:
  • token: string, previously return from from send_content_intent
  • username: string, username of user to find
  • format: string: currently just 'file', could be more later
  • data: keyed array, information per format
    • shared keys, expected by all formats:
      • totalsize: total filesize of included files (in bytes) - used for quota checks
    • 'file' format keys:
      • filesmanifest: keyed array of file information (keyed by filename):
        • filename: desired name of file
        • sha1: sha1 of file
        • size: size of file (in bytes)
      • zipfilesha1: sha1 of the zipfile containing the file(s)
      • zipfilesize: size of the zipfile containing the file(s)
  • wait: boolean. whether the remote system is expected to immediately launch a request to fetch file or queue it for cron.
• Returns: Stdclass object with keys:
  • status: boolean, success or failure
  • type: string, 'queued' or 'complete'
  • querystring: string, used for the final 'continue to portfolio' link (eg ?folder=6&file=6 to highlight new files that were added)

fetch_file

• Defined in: portfolio/type/mahara/lib.php
• Implemented in: Moodle.
• Parameters:
  • token: string, same that was returned in send_content_intent and used subsequently in send_content_ready
• Returns: base64 encoded file (currently a zipfile, as can include multiple files)