JavaScript Inter Application Communication is designed to allow applications within a page to exchange data. This library is made for broadcasting messages on topic.

It is based on three functions:

A subscription to a topic will receive any subtopic messages. For example, an application subscribed to "/eXo/application" will receive messages sent on the "/eXo/application/map" topic. A message sent on "/eXo", however, would not be received.

Subscript ion Topics

Library

The Inter Application Communication library is found in JPP_HOME/gatein/gatein.ear/eXoResources.war/javascript/eXo/core/Topic.js

/**

 * publish is used to publish an event to the other subscribers to the given

channels

 * @param {Object} senderId is a string that identify the sender

 * @param {String} topic is the topic that the message will be published

 * @param {Object} message is the message that's going to be delivered to the

subscribers to the topic

 */

Topic.prototype.publish = function(/*Object*/ senderId, /*String*/ topicName,

/*Object*/ message ) { ... }

/**

 * isSubscribed is used to check if a function receive the events from a topic

 * @param {String} topic The topic.

 * @param {Function} func is the name of the function of obj to call when a message

is received on the topic

 */

Topic.prototype.isSubscribed = function(/*String*/ topic, /*Function*/ func) { ...

}

/**

 * subscribe is used to subscribe a callback to a topic

 * @param {String} topic is the topic that will be listened

 * @param {Function} func is the name of the function of obj to call when a message

is received on the topic

 *

 * func is a function that take a Object in parameter. the event received have this

format:

 * {senderId:senderId, message:message, topic: topic}

 *

 */

Topic.prototype.subscribe = function(/*String*/ topic, /*Function*/ func) { ... }

/**

 * unsubscribe is used to unsubscribe a callback to a topic

 * @param {String} topic is the topic

 * @param {Object} id is the id of the listener we want to unsubscribe

 */

Topic.prototype.unsubscribe = function(/*String*/ topic, /*Object*/ id) { ... }

Topic.prototype.initCometdBridge = function() { ... }

Syntax

The three messaging functions require particular objects and definitions in their syntax:

Example of JavaScript events usage

<%@ taglib uri="http://java.sun.com/portlet" prefix="portlet" %>

<portlet:defineObjects/>

<div>

  <p>

    Received messages:

    <div id="received_<portlet:namespace/>">     ssss



    </div>

  </p>



  <p>

    Send message:

    <input type="text" id="msg_<portlet:namespace/>"/> <a href="#"

onclick="send_<portlet:namespace/>();">send</a>

  </p>

</div>

<script type="text/javascript">



  Function.prototype.bind = function(object) {

    var method = this;

      return function() {

      method.apply(object, arguments);

    }

  }



  function send_<portlet:namespace/>() {

    var msg = document.getElementById("msg_<portlet:namespace/>").value;

    eXo.core.Topic.publish("<portlet:namespace/>", "/demo", msg);

  }



  function Listener_<portlet:namespace/>(){



  }



  Listener_<portlet:namespace/>.prototype.receiveMsg = function(event) {

    document.getElementById("received_<portlet:namespace/>").innerHTML =

      document.getElementById("received_<portlet:namespace/>").innerHTML + "<br

/>* " +

      event.senderId + ": " + event.message;

  }



  function init_<portlet:namespace/>() {

    var listener_<portlet:namespace/> = new Listener_<portlet:namespace/>();

    eXo.core.Topic.subscribe("/demo",

listener_<portlet:namespace/>.receiveMsg.bind(listener_<portlet:namespace/>));

  }



  init_<portlet:namespace/>();

</script>