Setup
There are 2 ways to initialise the component.
Automatic
Add data-ecl-auto-init="Range" attribute to form group element's markup Also make sure to have the markup usng the correct data attributes
<div class="ecl-form-group" data-ecl-range data-ecl-auto-init="Range">
...
<input class="ecl-range" data-ecl-range-input ... />
...
<div class="ecl-range__value">
...
<span class="ecl-range__value-current" data-ecl-range-value-current></span>
</div>
</div>
Use the ECL library's autoInit() (ECL.autoInit()) when your page is ready or other custom event you want to hook onto.
Manual
Get target element, create an instance and invoke init().
Given you have 1 element with an attribute data-ecl-range on the page:
var elt = document.querySelector('[data-ecl-range]');
var range = new ECL.Range(elt);
range.init();