Alright, I uderstand.
I want to show a code fragment from my modified Hello World:
<script>
/////////////////PushPage Configuration
var debugAlerts = true;
var remoteAlerts = false;

var page = new PushPage();
page.context.setDomain("ufandd.local");
page.onEngineCreation = function(lsEngine) {
lsEngine.connection.setLSHost("ufdcrdev0005.ufandd .local");
lsEngine.connection.setLSPort(8080);
lsEngine.context.setDebugAlertsOnClientError(debug Alerts);
lsEngine.context.setRemoteAlertsOnClientError(remo teAlerts);

lsEngine.connection.setAdapterName("PROXY_HELLOWOR LD");
lsEngine.changeStatus("STREAMING");
}
page.bind();
page.createEngine("HelloWorldApp", "LS", "SHARE_SESSION");

var pushtable = new OverwriteTable(null, null, "MERGE");
page.addTable(pushtable, "hellotable");
pushtable.onItemUpdate =
function(itemPos, updateInfo, itemName)
{
// send completed scan to the front-end
alert(updateInfo.getNewValue(itemPos));
serverData(updateInfo.getNewValue(itemPos));
};
</script>
As you can see I am overriding onItemUpdate because I also want to send data to somewherre else. It works fine, sort of. For the very first time alert box will pop up only once (as expected), but next data update will trigger the alert box twice: first with an empty value, second with the real value.

Can you tell me what am I doing wrong here?

BTW, my adapter's console shows one value every time.