GTM Mutation Event

GTM mutation event observer.js

<script>  
  var contentDiv = document.querySelector(".et-pb-contact-message");
  var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
  var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
      if(mutation.type==="childList"&& contentDiv.innerHTML.indexOf("Merci pour votre e-mail") !=-1) {
        dataLayer.push({'event': 'contactFormSent'});
        observer.disconnect();
      }
    });    
  });
  var config = { attributes: false, childList: true, characterData: true }
  observer.observe(contentDiv, config);
  </script>