Development:Messaging 2.0

The messaging system in 2.0 has been revamped significantly. It is now event-driven, and allows users to control exactly what messages they receive and how.

How to enable it

Admin > Optional subsystems > Enable messaging system = Yes

How to configure it

Visit your own profile page (you need moodle/user:editownmessageprofile permission). Note that the types of messages listed in the "Configure destinations for incoming messages" box is determined by the contents of the message_providers table.

How it works

Providers (input)

We have Events called "message_send" that look like this:

$eventdata = new object(); $eventdata->component = 'mod_forum'; // the component sending the message. Along with name this must exist in the table message_providers $eventdata->name = 'posts'; // type of message from that module (as module defines it). Along with component this must exist in the table message_providers $eventdata->userfrom = $userfrom; // user object $eventdata->userto = $userto; // user object $eventdata->subject = $postsubject; // very short one-line subject $eventdata->fullmessage = $posttext; // raw text $eventdata->fullmessageformat = FORMAT_PLAIN; // text format $eventdata->fullmessagehtml = $posthtml; // html rendered version $eventdata->smallmessage = ; // useful for plugins like sms or twitter

events_trigger('message_send', $eventdata);

The name of each provider is a string with a name like messageprovider:$name from the component lang file (in this case, forum.php is derived automatically from mod/forum):

$string['messageprovider:posts'] = 'Subscribed forum posts'; $string['messageprovider:digests'] = 'Subscribed forum digests';

More providers can be added throughout Moodle as necessary, it's quite easy. See the Events API for info.

Processors (output)

In /message/output there are full Moodle plugins for each type of output.

Currently we have support for email, jabber and web-based popups. Could add twitter and SMS quite easily.

Each plugin simply extends a class called "message_output" in /message/output/lib.php with methods such as:

function send_message($message) {

  // Given a message object and user info, this actually sends it.

}

function config_form($preferences) {

  // This defines the little form fragment on the config page

}

function process_form($form, &$preferences) {

  // This processes the data from the config form fragment

}

function load_data(&$preferences, $userid) {

  // This loads up prefs for this plugin

}

It should also provide a messageprocessor_xxxxx.php language file (where xxxxx is the name) and inside is an xxxxx string with the name of the processor, like this:

$string['jabber'] = 'Jabber message';

Finally, there should be a lib.php file containing an install routine to install itself as a message processor:

function jabber_install(){

   global $DB;

   $result = true;

   $provider = new object();
   $provider->name  = 'jabber';
   if (!$DB->insert_record('message_processors', $provider)) {
       $result = false;
   }
   return $result;

}

And a version.php file: $plugin->version = 2008090900; $plugin->requires = 2008091500;

See also

• GSOC/2008
• Messaging improvements, a GSOC 2007 project
• Events API
• MDL-10107