javascript - Multiple modals overlay

Question

I need that the overlay shows above the first modal, not in the back.

$('#openBtn').click(function(){
$('#myModal').modal({show:true})
});

<a data-toggle="modal" href="#myModal" class="btn btn-primary">Launch modal</a>

<div class="modal" id="myModal">
<div class="modal-dialog">
      <div class="modal-content">
        <div class="modal-header">
          <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
          <h4 class="modal-title">Modal title</h4>
        </div><div class="container"></div>
        <div class="modal-body">
          Content for the dialog / modal goes here.
          <br>
          <br>
          <br>
          <br>
          <br>
          <a data-toggle="modal" href="#myModal2" class="btn btn-primary">Launch modal</a>
        </div>
        <div class="modal-footer">
          <a href="#" data-dismiss="modal" class="btn">Close</a>
          <a href="#" class="btn btn-primary">Save changes</a>
        </div>
      </div>
    </div>
</div>
<div class="modal" id="myModal2" data-backdrop="static">
<div class="modal-dialog">
      <div class="modal-content">
        <div class="modal-header">
          <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
          <h4 class="modal-title">Second Modal title</h4>
        </div><div class="container"></div>
        <div class="modal-body">
          Content for the dialog / modal goes here.
        </div>
        <div class="modal-footer">
          <a href="#" data-dismiss="modal" class="btn">Close</a>
          <a href="#" class="btn btn-primary">Save changes</a>
        </div>
      </div>
    </div>
</div>


<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.0.0/css/bootstrap.min.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.0.0/js/bootstrap.min.js"></script>

Answer 1

After seeing many fixes for this, and none of them were exactly what I needed I've came up with a even shorter solution that is inspired by @YermoLamers & @Ketwaroo.

Backdrop z-index fix
This solution uses a setTimeout because the .modal-backdrop isn't created when the event show.bs.modal is triggered.

$(document).on('show.bs.modal', '.modal', function () {
    var zIndex = 1040 + (10 * $('.modal:visible').length);
    $(this).css('z-index', zIndex);
    setTimeout(function() {
        $('.modal-backdrop').not('.modal-stack').css('z-index', zIndex - 1).addClass('modal-stack');
    }, 0);
});

• This works for every .modal created on the page (even dynamic modals)
• The backdrop instantly overlays the previous modal

Example jsfiddle

If you don't like the hardcoded z-index for any reason you can calculate the highest z-index on the page like this:

var zIndex = Math.max.apply(null, Array.prototype.map.call(document.querySelectorAll('*'), function(el) {
  return +el.style.zIndex;
})) + 10;

Scrollbar fix
If you have a modal on your page that exceeds the browser height, then you can't scroll in it when closing an second modal. To fix this add:

$(document).on('hidden.bs.modal', '.modal', function () {
    $('.modal:visible').length && $(document.body).addClass('modal-open');
});

Versions
This solution is tested with bootstrap 3.1.0 - 3.3.5