Bootstrap Modal Responsive - Height

Question

I need a responsive modal that adapts the height of the browser.

If the whole modal does not reach the height the scroll will not be shown, but if it exceeds the size/height, the scroll will be shown in the modal body. Header and Footer continue to be shown.

╔════════════════════════════X
║         **HEADER**         ║ ---> height do modal (header + budy +   
╠════════════════════════════╣      footer) tem que ser no máximo 
║ - aaaaaaaaa              ║ ║      to tamanho da janela/browser.
║ - eeeeeeeee              ║ ║ 
║ - ddddddddd              ║ ║ 
║ - aaaaaaaaa              ║ ║ 
║ - ccccccccc              ║ ║
║ - bbbbbbbbb              ║v║ ---> Scroll (Somente no Body)
╠════════════════════════════╣
║         **FOOTER**         ║
╚════════════════════════════╝  


<div id="idModal" class="modal fade">
<div class="modal-dialog">
    <div class="modal-content">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            <h4 class="modal-title">Modal title</h4>
        </div>
        <div class="modal-body" >
         - aaaaaaaaa
         - eeeeeeeee
         - ddddddddd
         - aaaaaaaaa
         - ccccccccc
         - bbbbbbbbb
        </div>
        <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Fechar</button>
        </div>
    </div>
 </div>

Answer 1

You can use an event resize and the native modal callback. First add this CSS:

.modal-content{
   max-height: 100%; /*altura da modal*/
}

.modal-dialog{
   height: 100%; /*altura da view da modal*/
   margin-top: 0;
}

.modal-body{
   overflow: auto; /*habilita o overflow no corpo da modal*/
}

And the jQuery:

<script>
$(window).on('resize', function(){
   $this = $('#idModal');
   if($this.hasClass('show')){
      var budy = $this.find('.modal-body');
      var temScrol = budy.get(0).scrollHeight > budy.get(0).clientHeight;

      var mdheader = $this.find('.modal-header').outerHeight();
      var mdfooter = $this.find('.modal-footer').outerHeight();
      var mdbody = window.innerHeight-(mdheader+mdfooter);

      $this.find('.modal-body').css({
         'height': temScrol ? mdbody+'px' : 'auto'
      });
   }
});
$('#idModal').on('shown.bs.modal', function(){
   $(window).trigger('resize');
});
</script>

Example:

$(window).on('resize', function(){
   $this = $('#idModal');
   if($this.hasClass('show')){
      var budy = $this.find('.modal-body');
      var temScrol = budy.get(0).scrollHeight > budy.get(0).clientHeight;

      var mdheader = $this.find('.modal-header').outerHeight();
      var mdfooter = $this.find('.modal-footer').outerHeight();
      var mdbody = window.innerHeight-(mdheader+mdfooter);

      $this.find('.modal-body').css({
         'height': temScrol ? mdbody+'px' : 'auto'
      });
   }
});
$('#idModal').on('shown.bs.modal', function(){
   $(window).trigger('resize');
});

.modal-content{
   max-height: 100%; /*altura da modal*/
}

.modal-dialog{
   height: 100%; /*altura da view da modal*/
   margin-top: 0 !important;
}

.modal-body{
   overflow: auto; /*habilita o overflow no corpo da modal*/
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">

<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#idModal">
  Abrir modal
</button>
<div id="idModal" class="modal fade">
<div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            <h4 class="modal-title">Modal title</h4>
        </div>
        <div class="modal-body" >
         - aaaaaaaaa
         - eeeeeeeee
         - ddddddddd
         - aaaaaaaaa
         - ccccccccc
         - bbbbbbbbb
         <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>

        </div>
        <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Fechar</button>
        </div>
    </div>
 </div>

Here in the snippet the behavior is a little different from the browser, by this can appear a scroll bar in the window when running the example.