Masking input fields with Alpine.js
There are times when creating a form where a field needs its content in a certain state. This can be something as simple as a date field where the field needs to look like
By default HTML doesn't have the ability to make these custom masks for the inputted content. However, if the site is using Alpine.js then the Mask plugin can be used to achieve this.
<!-- Alpine Plugins --> <script defer src="https://unpkg.com/@firstname.lastname@example.org/dist/cdn.min.js"></script> <!-- Alpine Core --> <script defer src="https://email@example.com/dist/cdn.min.js"></script>
npm install @alpinejs/mask
import Alpine from 'alpinejs' import mask from '@alpinejs/mask' Alpine.plugin(mask)
Using the Mask plugin
With the mask plugin now available within the HTML it doesn't take too much to be able to implement it into a page. The first thing is to decide what the mask will need to be, to do this the Mask plugin has three different characters that are used to create the mask.
*can be used for any character
acan be used for aplha characters (a-z,A-Z)
9can be used for numeric characters (0-9)
Using the example from the introduction
DD/MM/YYYY the mask that will be used will be
To add the mask to text input box the following can be used
<input type="text" name="dob" x-data x-mask="99/99/9999" />
As seen in the above example there are two non-standard HTML attributes. The first is the normal Alpine.js
x-data this ensures that Alpine.js is looking at the element. The second attribute is
x-mask, this is the attribute used for defining the mask itself.