<div>

  <h2>Network / Communication</h2>

  <h3>Client-to-server JSON-based protocol</h3>

  <p>
    In 1.5 we replaced the communication between server and client with a new, JSON-based format.
    Now, the client uses the same format to report changes to the server.
    With this change, the entire communication uses the JSON protocol.
    No HTTP request parameters are involved anymore.
    All widgets LCAs have been reworked to handle the new JSON-based message.
  </p>
  <p>
    <img class="framed" src="images/Client-to-server-JSON.png" />
  </p>
  <p>
    The exact format is described in the
    <a href="http://wiki.eclipse.org/RAP/Protocol">RAP Protocol wiki page</a>.
  </p>

  <h2>API Changes</h2>

  <h3>Removed deprecated classes</h3>

  <p>
    During the API clean-up, the following deprecated classes have been removed.
  </p>
  <dl>
    <dt>AdapterFactory</dt>
    <dd>removed without a replacement together with the extension point,
      see <a href="https://bugs.eclipse.org/bugs/buglist.cgi?quicksearch=344541">bug 344541</a></dd>
    <dt>ResourceManagerFactory</dt>
    <dd>remove withot a replacement,
      see <a href="https://bugs.eclipse.org/bugs/buglist.cgi?quicksearch=348476">bug 348476</a></dd>
  </dl>

  <h3>Changes in LCA Utils</h3>

  <p>
    To read the properties from a JSON request, we made some changes to the classes
    <em>WidgetLCAUtil</em> and <em>ControlLCAUtils</em>.
    If you've developed custom widgets that use them, please refer to the JavaDoc of these classes
    for details.
  </p>

  <h2>New Client API</h2>

  <p>
    Now that alternative clients can be connected to a RAP server, applications will need to
    distinguish between different clients, e.g. to render parts differently on certain clients.
    Clients with additional capabilities like gps, camera, etc. should also be able to expose
    those client-specific features to applications.
  </p>

  <p>
    To support those cases, we added a service provider interface <em>Client</em> that can be
    acquired using the new method <em>RWT.getClient()</em>.
    Client implementations can provide services, such as a geo-location service, a script execution
    service, etc. Here's an example:
  </p>

<pre class="lang-java">
Client client = RWT.getClient();
LocationService service = client.getService( LocationService.class );
if( service != null ) {
  service.getAddress();
  ...
}
</pre>

  <p>
    Unless you have a custom client implementation installed, <em>RWT.getClient()</em> will always
    return an instance of <em>WebClient</em>.
    The web client does not provide any services yet. But we plan to implement at least a script
    execution service in the next milestone.
  </p>

  <p>
    Please consider this new API as <strong>provisional</strong>.
    It may become necessary to change it before the release.
  </p>

</div>