Get scrollHeight to adjust textarea size

Community Usage questions
1

Hello,
I am trying to something like this:

I can set interval like so:

setInterval(function(){
  setVar("this", "height", 0)
  setVar("this", "height", getVar("this", "scrollHeight"));
}, 50)

after setting:
height: VAR{height, 100}

But how do I get the value for scrollHeight?

Note that I ultimately want to do this but with an expanding textarea:

Thanks in advance

2 
setInterval(function(){
  setVar("this", "height", 0)
  setVar("this", "height", (get("this").split(/\r|\r\n|\n/).length * getVar("this", "line-height") * getVar("this", "font-size")));
}, 50)

As there is no asYouType for textarea, I guess this could just go in onValue without the timer.

3

Textarea's scrollHeight attribute is not exposed, your second post is pretty much the only option available (but you'd need to provide line-height and font-size values since these are not defined as custom variables).