when classes change event listener js
const mutationObserver = new MutationObserver(mutationsList => {
mutationsList.forEach(mutation => {
if (mutation.attributeName === 'class') {
// classes have changed
}
});
});
mutationObserver.observe(
// a document object you want to watch. some examples of document objects:
// document.getElementById('id')
// document.getElementsByClassName('class')[5]
// document.querySelector('[query=selector]')
// etc
,{ attributes: true }
)
// when you wanr to remove the listener
mutationObserver.disconnect();