Multiple Modal positions in Bootstrap 4

Question

In a previous post I was aided in getting modals aligned left and right, and this works fine. Now, I wish to add "standard" modal in the center, however, the solution to the left and right alignment of the modals, seems to have killed off any standard modals. How can I get the standard modals to work, along with the left and right align?

JSFIDDLE

For some reason, links to js fiddle are not enough, and code is required..

<div class="container">
    <div class="row">
        <div class="col">
            <h1>Some heading</h1>
            <p>This is not a love song</p>
            <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#leftModal">Left</button>
            <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#rightModal">Right</button>
            <button type="button" class="btn btn-primary" data-toggle="modal" data-target="middleModal">Middle</button>
        </div>
    </div>
</div>

<!-- Modal -->
<div class="modal fade" id="rightModal" tabindex="-1" role="dialog" aria-labelledby="rightModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-dialog-slideout" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="rightModalLabel">Right On</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        Right Modal
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- Left modal -->
<div class="modal fade" id="leftModal" tabindex="-1" role="dialog" aria-labelledby="leftModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-dialog-slideout" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="leftModalLabel">Left On</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        Left Modal
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- Button trigger modal -->


<!-- Middle Modal -->
<div class="modal fade" id="middleModal" tabindex="-1" role="dialog" aria-labelledby="middleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="middleModalLabel">Middle Modal</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
      </div>
    </div>
  </div>
</div>

#rightModal .modal-dialog-slideout {min-height: 100%; margin: 0 0 0 auto;background: #fff;}
.modal.fade .modal-dialog.modal-dialog-slideout {-webkit-transform: translate(100%,0)scale(1);transform: translate(100%,0)scale(1);}
.modal.fade.show .modal-dialog.modal-dialog-slideout {-webkit-transform: translate(0,0);transform: translate(0,0);display: flex;align-items: stretch;-webkit-box-align: stretch;height: 100%;}
.modal.fade.show .modal-dialog.modal-dialog-slideout .modal-body{overflow-y: auto;overflow-x: hidden;}
.modal-dialog-slideout .modal-content{border: 0;}
.modal-dialog-slideout .modal-header, .modal-dialog-slideout .modal-footer {height: 69px; display: block;}
#rightModal .modal-dialog-slideout .modal-header h5 {float:left;color:blue;}

#leftModal .modal-dialog-slideout {min-height: 100%; margin: 0 auto 0 0;background: #fff;}
#leftModal .modal-dialog-slideout .modal-header h5 {float:left;color:red;}

#leftModal.modal.fade:not(.show) .modal-dialog.modal-dialog-slideout {
    -webkit-transform: translate(100%,0)scale(1);
    transform: translate(-100%,0)scale(1);
}

Answer 1

All modals are working now. You data-target was incorrect for your middle modal. I have fixed up some CSS as well.

Live Demo:

#rightModal .modal-dialog-slideout {
  min-height: 100%;
  margin: 0 0 0 auto;
  background: #fff;
}

.modal.fade .modal-dialog.modal-dialog-slideout {
  -webkit-transform: translate(100%, 0)scale(1);
  transform: translate(100%, 0)scale(1);
}

.modal.fade.show .modal-dialog.modal-dialog-slideout {
  -webkit-transform: translate(0, 0);
  transform: translate(0, 0);
  display: flex;
  align-items: stretch;
  height: 100%;
}

.modal.fade.show .modal-dialog.modal-dialog-slideout .modal-body {
  overflow-y: auto;
  overflow-x: hidden;
}

.modal-dialog-slideout .modal-content {
  border: 0;
}

.modal-dialog-slideout .modal-header,
.modal-dialog-slideout .modal-footer {
  height: 69px;
  display: block;
}

#rightModal .modal-dialog-slideout .modal-header h5 {
  float: left;
  color: blue;
}

#leftModal .modal-dialog-slideout {
  min-height: 100%;
  margin: 0 auto 0 0;
  background: #fff;
}

#leftModal .modal-dialog-slideout .modal-header h5 {
  float: left;
  color: red;
}

#leftModal.modal.fade:not(.show) .modal-dialog.modal-dialog-slideout {
  -webkit-transform: translate(100%, 0)scale(1);
  transform: translate(-100%, 0)scale(1);
}

<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">

<!-- jQuery library -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>

<!-- Popper JS -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>

<!-- Latest compiled JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
<div class="container">
  <div class="row">
    <div class="col">
      <h1>Some heading</h1>
      <p>This is not a love song</p>
      <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#leftModal">Left</button>
      <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#rightModal">Right</button>
      <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#middleModal">Middle</button>
    </div>
  </div>
</div>

<!-- Right Modal -->
<div class="modal fade" id="rightModal" tabindex="-1" role="dialog" aria-labelledby="rightModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-dialog-slideout" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="rightModalLabel">Right On</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        Right Modal
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- Left modal -->
<div class="modal fade" id="leftModal" tabindex="-1" role="dialog" aria-labelledby="leftModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-dialog-slideout" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="leftModalLabel">Left On</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        Left Modal
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

<!-- Button trigger modal -->


<!-- Middle Modal -->
<div class="modal fade" id="middleModal" tabindex="-1" role="dialog" aria-labelledby="middleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="middleModalLabel">Middle Modal</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
      </div>
    </div>
  </div>
</div>