HTMLAttributeChangeDetector.js

function attributeChangeDetector(element, callback) {
  var MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver;

  var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
      if (mutation.type == 'attributes') {
        console.log('Attribute ' + mutation.attributeName + ' changed');
        !!callback && callback(mutation);
      }
    });
  });

  observer.observe(element, {
    attributes: true
  });
}