Wait for element to be available in DOM

WaitForElement.js

function waitForElement(selector, time) {
  if (document.querySelector(selector) !== null) {
      alert("The element is displayed, you can put your code instead of this alert.")
      return;
  }
  else {
      setTimeout(function() {
          waitForElementToDisplay(selector, time);
      }, time);
  }
}