change Dom element based on firebase admin value events

Question

I have a simple HTML page printed out inside a Servlet. Here I have setup firebase admin sdk and have set a value event listener for a path.

When the events fire, I wish

Answer 1

With servlets, your clients won't see any page updates until they send a new request to your application server. What you can do is get your ValueEventListener to update the state of an in-memory object. Then your servlet can read the latest state of that object whenever constructing the HTML output.

Answer 2

So i managed to solve this using a JSP instead of a Servelet.

In either case, the solution was to tranfer all the logic to a JavaScript function. Then calling the said function on body load.

onload=callthefunction()

The firebase listeners were converted from java to the JavaScript version:

on()
off()

This way there is need to call ajax or anything and the elements that need to be changed can be directly altered from JavaScript