[jquery] How do I get the real .height() of a overflow: hidden or overflow: scroll div?

I have a question regarding how to get a div height. I'm aware of .height() and innerHeight(), but none of them does the job for me in this case. The thing is that in this case I have a div that is overflown width a overflow: scroll and the div has a fixed height.

If I use .height() or innerHeight(), both of them gives me the height of the visible area, but if I want the overflown taken in to account, how do I go about?

Another simple solution (not very elegant, but not too ugly also) is to place a inner div / span then get his height ($(this).find('span).height()).

Here is an example of using this strategy:

$(".more").click(function(){_x000D_
if($(this).parent().find('.showMore').length) {_x000D_
$(this).parent().find('.showMore').removeClass('showMore').css('max-height','90px');_x000D_
$(this).parent().find('.more').removeClass('less').text('More');_x000D_
} else {_x000D_
$(this).parent().find('.text').addClass('showMore').css('max-height',$(this).parent().find('span').height());_x000D_
$(this).parent().find('.more').addClass('less').text('Less');_x000D_
}_x000D_
});

* {transition: all 0.5s;}_x000D_
.text {position:relative;width:400px;max-height:90px;overflow:hidden;}_x000D_
.showMore {}_x000D_
.text::after {_x000D_
  content: "";_x000D_
    position: absolute; bottom: 0; left: 0;_x000D_
        box-shadow: inset 0 -26px 22px -17px #fff;_x000D_
    height: 39px;_x000D_
  z-index:99999;_x000D_
  width:100%;_x000D_
  opacity:1;_x000D_
}_x000D_
.showMore::after {opacity:0;}_x000D_
.more {border-top:1px solid gray;width:400px;color:blue;cursor:pointer;}_x000D_
.more.less {border-color:#fff;_x000D_
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div>_x000D_
<div class="text">_x000D_
<span>_x000D_
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum._x000D_
</span></div>_x000D_
<div class="more">More</div>_x000D_
</div>

(This specific example is using this trick to animate the max-height and avoiding animation delay when collapsing (when using high number for the max-height property).

Other possibility would be place the html in a non overflow:hidden element placed 'out' of screen, like a position absolute top and left lesse then 5000px, then read this elements height. Its ugly, but work well.

I have just cooked up another solution for this, where it's not longer necessary to use a -much to high- max-height value. It needs a few lines of javascript code to calculate the inner height of the collapsed DIV but after that, it's all CSS.

1) Fetching and setting height

Fetch the inner height of the collapsed element (using scrollHeight). My element has a class .section__accordeon__content and I actually run this in a forEach() loop to set the height for all panels, but you get the idea.

document.querySelectorAll( '.section__accordeon__content' ).style.cssText = "--accordeon-height: " + accordeonPanel.scrollHeight + "px";

2) Use the CSS variable to expand the active item

Next, use the CSS variable to set the max-height value when the item has an .active class.

.section__accordeon__content.active {
  max-height: var(--accordeon-height);
}

Final example

So the full example goes like this: first loop through all accordeon panels and store their scrollHeight values as CSS variables. Next use the CSS variable as the max-height value on the active/expanded/open state of the element.

Javascript:

document.querySelectorAll( '.section__accordeon__content' ).forEach(
  function( accordeonPanel ) {
    accordeonPanel.style.cssText = "--accordeon-height: " + accordeonPanel.scrollHeight + "px";
  }
);

CSS:

.section__accordeon__content {
  max-height: 0px;
  overflow: hidden;
  transition: all 425ms cubic-bezier(0.465, 0.183, 0.153, 0.946);
}

.section__accordeon__content.active {
  max-height: var(--accordeon-height);
}

And there you have it. A adaptive max-height animation using only CSS and a few lines of JavaScript code (no jQuery required).

Hope this helps someone in the future (or my future self for reference).

For more information about .scrollHeight property refer to the docs:

The Element.scrollHeight read-only attribute is a measurement of the height of an element's content, including content not visible on the screen due to overflow. The scrollHeight value is equal to the minimum clientHeight the element would require in order to fit all the content in the viewpoint without using a vertical scrollbar. It includes the element padding but not its margin.

For those that are not overflowing but hiding by negative margin:

$('#element').height() + -parseInt($('#element').css("margin-top"));

(ugly but only one that works so far)