How to Detect when sever communication is down?

I wnat to lock the current ui of server communication is down. It will be unlocked when server comunication is established again. But i wasnt able to find a way to detect the server status when comunication is down (eg when network cable is unpluged). is there a way to do that. any help would be appriciated…

The standard Vaadin mechanisms like Hearbeat are mainly made so that the server side notices when the client is gone (eg by closing the browser).
I don’t know of any built-in way to do this for the client but you could do this using Javascript. (see
). You could add your javascript by either making a Javascript extension maybe to the UI class or by creating and integrating a small simle Javascript Component.
Take a look at the Javascript section here:

hi Marius,

Thanks for the quick reply. I’ll try that out and see.