How to Center an ngx-bootstrap Modal with CSS

In this article, we’ll explain how to use CSS to center an ngx-bootstrap modal. ngx-bootstrap is an Angular component library based on the Bootstrap framework that includes some commonly used UI components, such as modals.

Read more: CSS Tutorial

Method 1: Using Flexbox Layout

Flexbox is a layout model in CSS3 that makes it easy to achieve centering effects.

First, we need to add the following CSS styles to the modal’s parent container:

.center-modal {
display: flex;
align-items: center;
justify-content: center;
} 

Next, add a parent container with the .center-modal class to the modal’s HTML:

<div class="modal fade"> 
<div class="modal-dialog center-modal"> 
<div class="modal-content"> 
<!-- Modal Content --> 
</div> 
</div>
</div>

This way, we can center the modal both horizontally and vertically.

Method 2: Using absolute positioning and the transform property

Another common method is to use absolute positioning and the transform property.

We can add the following CSS styles to the modal’s parent container:

.center-modal {
position: fixed;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
} 

Next, add a parent container with the .center-modal class to the modal’s HTML:

<div class="modal fade">
<div class="modal-dialog center-modal">
<div class="modal-content">
<!-- Modal content -->
</div>
</div>
</div>

This way, the modal will be centered on the screen.

Method 3: Dynamically Calculate the Position Using JavaScript

If the above methods don’t meet your needs, you can also use JavaScript to dynamically calculate the modal’s position.

First, let’s add a unique id attribute to the modal’s parent container:

<div class="modal fade" id="my-modal"> 
<div class="modal-dialog"> 
<div class="modal-content"> 
<!-- Modal content --> 
</div> 
</div> 
</div> 

Then, add the following JavaScript code:

var modal = document.getElementById('my-modal'); 
modal.style.display = 'block'; 

var modalWidth = modal.offsetWidth; 
var modalHeight = modal.offsetHeight; 

modal.style.top = '50%'; 
modal.style.left = '50%'; 
modal.style.transform = 'translate(-' + (modalWidth / 2) + 'px, -' + (modalHeight / 2) + 'px)'; 

This way, the modal will be dynamically calculated and centered on the screen.

Summary

This article introduced how to center an ngx-bootstrap modal using CSS. We can achieve this using flexbox layouts, absolute positioning, and the transform property, or dynamically calculating the position using JavaScript. Choosing the right method depends on your specific situation, but we hope you find these methods helpful.