how to get notified, if user change custom widget theme from the appearance in the setting

I want an event or variable that holds the current theme of custom widget
for example, if the user changed mapped device or data points, we get information in the config variable
similarly, how to get the current theme of the custom widget?

Hi,

widgets and their configuration are basically ManagedObjects. You could use an Apama EPL App like below, to get a change event of that.

monitor MySampleMonitor {
	action onload() {
		monitor.subscribe(ManagedObject.SUBSCRIBE_CHANNEL );
		on all ManagedObject(id="<Dashboard id. could be found in url>") as mo{
			log "Dashboard Update: " + mo.toString() at INFO;
		}
	}
}

You then could inspect certain values in the ManagedObject for any change you would like to track. Find a detailed description here:

Regards,

Marco