I want to size my webpart height after ContentRow is resized

Question

I want to size my webpart height after ContentRow is resized but how ?

If I add my code to last of the webpart page for javascript like this,

<script>
    var h = (document.getElementById("contentRow").clientHeight);
    console.log(h); // output is 7
    var elems = document.getElementsByClassName('my-webpart');
    for (var i = 0; i < elems.length; i++) {
        elems[i].style.height = h + 'px';
    }
</script>

I don't want to use window.load or jquery document ready as they take too much time to resize my webpart. I want my webpart to me contentRow height size as soon as possible.

EDIT

Where can I find code where SharePoint team is setting height on contentRow on page load or on page resize?

Because contentRow inherits from s4-workspace, lets find out where its height is set and what happens on window resize

Answer 1

Not able to find what i wanted but found a substitute,

document.getElementById('my-webpart').style.height = (document.documentElement.clientHeight - 80) + 'px';

Yes i changed class to id to shorten code but main thing is this,

(document.documentElement.clientHeight - 80) + 'px';