Using collapse on display:flex elements ie: row

[iatek]

I found this same problem in closed #20442, and I was wondering if it will be revisited for beta. Since row is display:flex, and collapse.show sets display:block, the displayed row is off.

<div class="container">
    <div class="row">
        <h4 class="col">
        <a href="#details" data-toggle="collapse">
            <span>Expand</span>
        </a>
      </h4>
    </div>
    <div id="details" class="row collapse" aria-expanded="false">
        <div class="col-6">
            <h3>Text</h3>
        </div>
        <div class="col-6">
            <h3>Text</h3>
        </div>
    </div>
    <div class="row" aria-expanded="true">
        <div class="col-6">
            <h3>Text</h3>
        </div>
        <div class="col-6">
            <h3>Text</h3>
        </div>
    </div>
</div>

http://codeply.com/go/UuAQvoRMiC

[emma-burrows]

In case I'm not the only one who can't access that codeply snippet, I also included one in the question that probably prompted this issue: http://stackoverflow.com/questions/43909742/bootstrap-4-alpha-6-collapsed-two-divs-side-by-side-are-stacked-when-expanded

[mdo]

The solution here isn't to swap the display value on .collapse classes. @Johann-S, I'm curious if the collapse plugin could read the initial display somehow? Otherwise there's no way around collapse being somewhat limited.

[Johann-S]

I don't see any reliable method to check that, but we can check if the element to collapse have .row class and apply a different class with display: flex;.
Does it sounds a good solution for you @mdo ?

Edit :
It can be done easely with :

.collapse {
  display: none;
  &.show {
    display: block;
  }
  &.row.show {
    display: flex;
  }
}

[mdo]

That fixes it for row, but what if someone has overridden a one-off row to say inline-flex that also collapses? This fixes one edge case, but doesn't provide much help otherwise.

[Johann-S]

I added a way to detect the use of flexbox in our Collapse plugins 🎆

[DDDgfx]

I think I am having this problem. I add the collapse class to a .row, and the result is child columns stack as if block elements. Is there a fix?