Update, as of Beta 3, [docs]:
Add .modal-dialog-centered to .modal-dialog to vertically center the modal.
Original answer:
SCSS:
.modal-dialog {
min-height: calc(100vh - 60px);
display: flex;
flex-direction: column;
justify-content: center;
overflow: auto;
@media(max-width: 768px) {
min-height: calc(100vh - 20px);
}
}
or unprefixed CSS:
.modal-dialog {
min-height: calc(100vh - 60px);
display: flex;
flex-direction: column;
justify-content: center;
overflow: auto;
}
@media(max-width: 768px) {
.modal-dialog {
min-height: calc(100vh - 20px);
}
}
Note 1: Please note fully prefixed CSS gradually becomes obsolete as browser support for certain properties changes. The right way of getting the updated prefixed CSS is to:
- copy/paste the unprefixed CSS into Autoprefixer.
- set the filter in the bottom box to the desired setting (for max. browser support use
> 0%).
- get the latest code from the box on the right.
Note 2: This answer was added in early stages of v4 (alpha 3 or 4), which is now currently in beta. You can safely replace the CSS part of this answer by adding the following classes to .modal-dialog:
h-100 d-flex flex-column justify-content-center my-0
..., as pointed out by @Androbaut in the comment below. You will still need the JavaScript (see below) to close the modal window on click tap below/above the modal window.
jQuery (needed to close modal on click/tap above/below):
$('.modal-dialog').on('click tap', function(e){
if ($(e.target).hasClass('modal-dialog')) {
$('.modal').modal('hide');
}
})
That's it.
Working snippet, fully-prefixed CSS and markup using different modal sizes:
$('.modal-dialog').on('click tap', function(e){
if ($(e.target).hasClass('modal-dialog')) {
$('.modal').modal('hide');
}
})
.modal-dialog {
min-height: -webkit-calc(100vh - 60px);
min-height: -moz-calc(100vh - 60px);
min-height: calc(100vh - 60px);
display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
display: flex;
-webkit-box-orient: vertical;
-webkit-box-direction: normal;
-webkit-flex-direction: column;
-moz-box-orient: vertical;
-moz-box-direction: normal;
-ms-flex-direction: column;
flex-direction: column;
-webkit-box-pack: center;
-webkit-justify-content: center;
-moz-box-pack: center;
-ms-flex-pack: center;
justify-content: center;
overflow: auto;
}
@media (max-width: 768px) {
.modal-dialog {
min-height: -webkit-calc(100vh - 20px);
min-height: -moz-calc(100vh - 20px);
min-height: calc(100vh - 20px);
}
}
/* you don't need the CSS below this line. It's mainly cosmetic and for aligning the modal launch buttons */
.modal-content {
display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
display: flex;
-webkit-box-orient: vertical;
-webkit-box-direction: normal;
-webkit-flex-direction: column;
-moz-box-orient: vertical;
-moz-box-direction: normal;
-ms-flex-direction: column;
flex-direction: column; }
.modal-content > * {
-webkit-box-flex: 0;
-webkit-flex: 0 0 auto;
-moz-box-flex: 0;
-ms-flex: 0 0 auto;
flex: 0 0 auto;
}
.modal-content > *.modal-body {
-webkit-box-flex: 1;
-webkit-flex-grow: 1;
-moz-box-flex: 1;
-ms-flex-positive: 1;
flex-grow: 1;
}
#Modal_2 .modal-content {
min-height: 50vh;
}
#Modal_3 .modal-content {
min-height: 85vh;
}
#Modal_4 .modal-content {
min-height: 200vh;
}
.full-page-center {
display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
display: flex;
-webkit-box-pack: center;
-webkit-justify-content: center;
-moz-box-pack: center;
-ms-flex-pack: center;
justify-content: center;
-webkit-box-align: center;
-webkit-align-items: center;
-moz-box-align: center;
-ms-flex-align: center;
align-items: center;
min-height: 100vh;
}
.full-page-center button {
margin: 15px;
}
@media (max-width: 768px) {
.full-page-center {
-webkit-flex-wrap: wrap;
-ms-flex-wrap: wrap;
flex-wrap: wrap;
}
.full-page-center button {
display: block;
min-width: 100%;
margin: 10px 15px;
}
.full-page-center::after {
display: none;
-webkit-box-flex: 0;
-webkit-flex-grow: 0;
-moz-box-flex: 0;
-ms-flex-positive: 0;
flex-grow: 0;
}
}
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.5/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://npmcdn.com/tether@1.2.4/dist/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.5/js/bootstrap.min.js"></script>
<div class="container full-page-center">
<button type="button" class="btn btn-primary btn-lg" data-toggle="modal" data-target="#Modal_1">
Tiny modal
</button>
<button type="button" class="btn btn-default btn-lg" data-toggle="modal" data-target="#Modal_2">
Normal modal
</button>
<button type="button" class="btn btn-success btn-lg" data-toggle="modal" data-target="#Modal_3">
Large modal
</button>
<button type="button" class="btn btn-warning btn-lg" data-toggle="modal" data-target="#Modal_4">
Very large modal
</button>
</div>
<div class="modal fade" id="Modal_1" tabindex="-1" role="dialog" aria-labelledby="modalLabel_1" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<h4 class="modal-title" id="modalLabel_1">Tiny modal</h4>
</div>
<div class="modal-body">
I am cute...
</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>
<div class="modal fade" id="Modal_2" tabindex="-1" role="dialog" aria-labelledby="modalLabel_2" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<h4 class="modal-title" id="modalLabel_2">Dull modal</h4>
</div>
<div class="modal-body">
I am normal...
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Some action</button>
</div>
</div>
</div>
</div>
<div class="modal fade" id="Modal_3" tabindex="-1" role="dialog" aria-labelledby="modalLabel_3" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<h4 class="modal-title" id="modalLabel_3">Don't call me fat</h4>
</div>
<div class="modal-body">
Call me "oversized".
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-success">Some action</button>
</div>
</div>
</div>
</div>
<div class="modal fade" id="Modal_4" tabindex="-1" role="dialog" aria-labelledby="modalLabel_4" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<h4 class="modal-title" id="modalLabel_4">Huge modal</h4>
</div>
<div class="modal-body">
Comments, anyone?
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-warning">Some action</button>
</div>
</div>
</div>
</div>
If you find any bugs or shortcomings please let me know. I will take the time to improve the answer and keep it useful. Help with this task is welcome.
