This library is intended to be used with 'plain JavaScript', AngularJS, and ReactJS applications (see Kaazing JavaScript Starter Applications and Kaazing Examples and Tutorials); it provides a JavaScript function that returns an object that can be used in the client application to interact with Kaazing Gateway.

• Install library with the Bower as specified in the README.
• Add the following scripts to your page:

<script src="bower_components/kaazing-javascript-universal-client/javascript/src/AngularUniversalClient.js"></script>
<script src="bower_components/kaazing-javascript-universal-client/javascript/src/JmsClient.js"></script>

Note: JmsClient.js is not needed when using the AMQP protocol.

• Install library with the NPM as specified in the README.
• Add the following scripts to your page:

<script src="node_modules/kaazing-javascript-universal-client/node_modules/kaazing-javascript-jms-client/JmsClient.js"></script>
<script src="node_modules/kaazing-javascript-universal-client/AngularUniversalClientNPM.js"></script>

Note: Addition of JmsClient.js is not needed when using AMQP protocol.

• Create an instance of the Universal Client Library.

   var client = UniversalClientDef(protocol);

  Where protocol is a string that specifies the protocol that should be used for communications:

  • 'jms' - for communication with the Kaazing JMS Gateway
  • 'amqp' - for communication with the Kaazing AMQP Gateway.

• Establish a connection

   client.connect(connectionInfo,onError,function(connection){
    ...
    });

  • connectionInfo is an object that includes:
    • URL (e.g. ws://localhost:8001/amqp or ws://localhost:8001/jms)
    • username (user name to be used to establish connection) and
    • password (user password to be used to establish connection)
  • onError: a function that is used for error handling in a format of function(error).
  • callback function to receive a connection object once connection is established.

  Note: If you want to add a logger to log library messages, add the following after creating the client:

   var client = UniversalClientDef(protocol);
   client.loggerFuncHandle = function (severity, message) {
    ...
    };

• Subscribe to topics of interest

var subscription; // will be registered as the subscription handle in the callback
client.connect(
    connectionInfo, // Connection info
    onError, // callback function to process errors
    function(connection){
        connection.subscribe(
            topicP, // Topic to send message
            topicS, // Topic to subscribe to receive messsages
            onMessage, // callback function to process received messages
            noLocal, // noLocal flag set to false - allow receiving your own messages
            function(sub){
                subscription = sub;
            });
        })

Where:

• topicP: Name of the publishing endpoint - AMQP exchange used for publishing or JMS Topic

• topicS: Name of the subscription endpoint - AMQP exchange used for subscription or JMS Topic

• onMessage: Function that will be used to process received messages from subscription endpoint in a format of function(message)

• noLocal: Flag indicating whether the client wants to receive its own messages (true) or not (false). That flag should be used when publishing and subscription endpoints are the same.

• callback function to receive subscription object Note Multiple subscriptions are allowed within single connection!

  • Add disconnect on window close (this example uses JQuery):

      $(window).unload(function() {
          client.disconnect();
      });

• To send messages use the sendMessage(msg) method of a subscription object where msgObject is the JavaScript object to be sent (it will be delivered as a JSON string).

   var sendMessage=function(msgObject){
       // Send message
       subscription.sendMessage(msg);
   }

As shown on the diagram above, Kaazing Universal Client works as following:

• Determine Client Library Facade based on the specified protocol

• Download all necessary JavaScript libraries including the needed Client Library Facade using RequireJS.

  • Notes:

  • Kaazing AMQP client libraries require Kaazing WebSocket library to be downloaded and instantiated first, to achieve this the Universal Client uses the following code:

    For Bower

    requirejs(['bower_components/kaazing-amqp-0-9-1-client-javascript/javascript/WebSocket.js'],function(){
        requirejs([
          'bower_components/jquery/dist/jquery.js',
          'bower_components/kaazing-amqp-0-9-1-client-javascript/javascript/Amqp-0-9-1.js',
          'bower_components/kaazing-javascript-universal-client/javascript/src/AmqpUniversalClient.js'
          ], function () {
            ...
            });
        });

    For NPM

    requirejs(['node_modules/kaazing-javascript-universal-client/node_modules/kaazing-javascript-gateway-client/WebSocket.js'],function(){
        requirejs([
          'node_modules/jquery/dist/jquery.js',
          'node_modules/kaazing-javascript-universal-client/node_modules/kaazing-javascript-amqp-client/AmqpClient.js',
          'node_modules/kaazing-javascript-universal-client/AmqpUniversalClient.js'
          ], function () {
        ...
        });
    });

  Bower and NPM implementations differ due to paths of the dependent packages.

  • Due to certain limitations, RequireJS cannot download the Kaazing JMSClient.js library hence it has to be included directly

• Instantiate required Client Facade Library that will interact with necessary Kaazing Javascript Client Libraries

• Pass the data to and from the Kaazing Javascript Client libraries via instantiated Client Facade Library

For more information about Client Facade libraries see AMQP Client Libraries Facade and JMS Client Libraries Facade.