Migration from OWF to IWC

This tutorial is for developers who are migrating applications previously developed for the Ozone Widget Framework (OWF) to use IWC. This tutorial has the following prerequisites:

Overview

This tutorial covers:

Handling the required JavaScript dependencies.
Differences in instantiating IWC vs OWF.

Handling the required JavaScript dependencies

OWF

In OWF, it was required that applications had to:

Include the owf-widget-min.js JavaScript library.
Place the rpc_relay.uncompressed.html file in the application's directory & give reference to it with: OWF.relayFile = '<DIR_PATH>/rpc_relay.uncompressed.html';

<html>
   <head>
     <script type="text/javascript" src="<DIR_PATH>/owf-widget-debug.js"></script>
     <script type="text/javascript">
       //The location is assumed to be at /<context>/js/eventing/rpc_relay.uncompressed.html if it is not set
       OWF.relayFile = '<DIR_PATH>/rpc_relay.uncompressed.html';
     </script>
   </head>
   <body></body>
</html>

IWC

In IWC, the two requirements above unfold as so:

Include the 'ozpIwc-client.min.js` JavaScript library.
No longer necessary

<html>
   <head>
     <script type="text/javascript" src="<DIR_PATH>/ozpIwc-client.min.js"></script>
   </head>
   <body></body>
</html>

Differences in instantiating IWC vs OWF

OWF

In OWF, it was required to wrap application logic in a callback to OWF.ready. When OWF was ready for the application, the application logic would run.

function initPage() {
  updateClock();
  msg = 'Running in OWF: ' + (OWF.Util.isRunningInOWF()?"Yes":"No");
  document.getElementById("message-panel").innerHTML = msg;
  document.getElementById("message-panel").style.display = 'block';
  setInterval('updateClock()', 1000 )
}
owfdojo.addOnLoad(function() {
  OWF.ready(initPage);
});

IWC

In IWC, the application does not need to wait for IWC to be ready to begin operation. All IWC operations will be queued if the IWC is not ready for the application. This means applications no longer have the Loading.. splash-screen of OWF.

A difference in IWC from OWF, the IWC isn't simply running by including the library, a connection to the IWC domain must be established (covered in the Quick Start tutorial). Syntactically this should not be alarming to developers as they need to reference an instance of ozpIwc.Client to use the IWC, and said reference prepares the IWC for use.

var client = new ozpIwc.Client({peerUrl: "http://localhost:13000"});
// all client requests will be queued until IWC is ready.

Knowing when the IWC Client Connects

While the client auto connects and will process any requests queued, the connect promise will resolve when the client is connected. This promise can be called ass often as desired, the client will not reconnect by calling it, rather it will reference the connection to resolve and move on to any chained functions.

var client = new ozpIwc.Client({peerUrl: "http://localhost:13000"});
client.connect().then(function(){
   // This asynchronous function runs once the client is connected.
});

The below code snippet demonstrates the use of the connect promise to write the client's unique address to the application once connected.