JAVASCRIPT

javascript wait for document load

document.addEventListener("DOMContentLoaded", function(event) { 
  //do work
});

wait for the dom to load javascript

document.addEventListener('DOMContentLoaded', (event) => {
  //the event occurred
})

wait for element to load javascript

var checkExist = setInterval(function() {
   if ($('#my-element').length) {
      console.log("Exists!");
      clearInterval(checkExist);
   }
}, 100); // check every 100ms