I start supporting reload extension on my custom wicketstuff-push (see the post). Let's see the code.
public abstract class CometdAbstractBehavior extends AbstractDefaultAjaxBehavior {
private static final long serialVersionUID = 1L;
// FIXME: put this in application scope, we may have several webapp using
// CometdBehavior in the same web container!
private final static String cometdServletPath = getCometdServletPath();
private static final ResourceReference COMETD =
new CompressedResourceReference(CometdAbstractBehavior.class, "org/cometd.js");
private static final ResourceReference JQ_JSON2 =
new CompressedResourceReference(CometdAbstractBehavior.class, "jquery/json2.js");
private static final ResourceReference JQ_COMETD =
new CompressedResourceReference(CometdAbstractBehavior.class, "jquery/jquery.cometd.js");
private static final ResourceReference COMETD_RELOAD =
new CompressedResourceReference(CometdAbstractBehavior.class, "org/cometd/ReloadExtension.js");
private static final ResourceReference JQ_COOKIE =
new CompressedResourceReference(CometdAbstractBehavior.class, "jquery/jquery.cookie.js");
private static final ResourceReference JQ_COMETD_RELOAD =
new CompressedResourceReference(CometdAbstractBehavior.class, "jquery/jquery.cometd-reload.js");
@Override
public void renderHead(final IHeaderResponse response) {
super.renderHead(response);
if (channelId == null) {
throw new IllegalArgumentException("ChannelId in a CometdBehavior can not be null");
}
response.renderJavascriptReference(COMETD);
response.renderJavascriptReference(JQ_JSON2);
response.renderJavascriptReference(JQ_COMETD);
response.renderJavascriptReference(COMETD_RELOAD);
response.renderJavascriptReference(JQ_COOKIE);
response.renderJavascriptReference(JQ_COMETD_RELOAD);
response.renderJavascript(getInitCometdScript(), "initCometd");
final String cometdInterceptorScript = getCometdInterceptorScript();
if (cometdInterceptorScript != null) {
response.renderJavascript(cometdInterceptorScript, "Interceptor"
+ getBehaviorMarkupId());
}
response.renderJavascript(getSubscriberScript(), "Subscribe"
+ getBehaviorMarkupId());
}
protected final CharSequence getInitCometdScript() {
return new PackagedTextTemplate(CometdBehavior.class, "CometdReloadInit.js").getString() +
getConfigureCometdScript() + getHandshakeCometdScript();
}
I add a javascript file. This code is written based on the reload example for jQuery (here).
/* handshake listener to report client IDs */
$.cometd.addListener("/meta/handshake", function(message)
{
if (message.successful)
{
$('#previous').html(org.cometd.COOKIE.get('demoLastCometdID'));
$('#current').html(message.clientId);
org.cometd.COOKIE.set('demoLastCometdID', message.clientId, {
'max-age': 300,
path : '/',
expires: new Date(new Date().getTime() + 300 * 1000)
});
}
else
{
$('#previous').html('Handshake Failed');
$('#current').html('Handshake Failed');
}
});
/* Setup reload extension */
$(window).unload(function()
{
$.cometd.reload();
});
Be care that this works on not only browser reloads, but also loading the same page with different parameters. It means, subscribing to the different channel also happens without handshake.
