JSFiddle - React, Tailwind, and code Playground

HTML

<div data-ololo="false" id="div">div</div>

JavaScript

var div = document.getElementById('div');

var MutationObserver = (function () {
	var pref = ['WebKit', 'Moz', 'O', 'Ms', ''];

	for (var i=0; i < pref.length; i++) {
		if (pref[i] + 'MutationObserver' in window) {
			return window[pref[i] + 'MutationObserver'];
		}
	}
	return false;
}());

new MutationObserver( function (mutations) {
	mutations.forEach( function (e, i) {
  
  	console.log('измененo')
		console.log(e);
	});
  
}).observe(div, {
	attributes: true,
});

div.dataset.ololo = true;