https://www.zwolsetheaters.nl/assets/js/helpers.js?v=HGrKdvmUXqEJb8FtU8ZsLaz1xOk0Jx-uSg48D1iyr6I

1window.on = function (eventName, selector, callback) {
2  eventName = eventName == "hover" ? "mouseenter" : eventName;
3
4  window.addEventListener("load", function () {
5    const elements = document.querySelectorAll("[data-id='" + selector + "']");
6    const fallbackElements = document.querySelectorAll(selector);
7
8    if (elements.length) {
9      elements.forEach(function (element) {
10        element.addEventListener(eventName, callback);
11      });
12    } else if (fallbackElements.length) {
13      fallbackElements.forEach(function (element) {
14        element.addEventListener(eventName, callback);
15      });
16    } else {
17      console.debug("Could not find any elements with selector:", selector);
18    }
19  });
20};