React

by davecranwell

HTML

<iframe id="myframe" src="//fiddle.jshell.net/xpvt214o/show/">
</iframe>

React

function ready(fn) {
  if (document.attachEvent ? document.readyState === "complete" : document.readyState !== "loading"){
    fn();
  } else {
    document.addEventListener('DOMContentLoaded', fn);
  }
}

ready(() => {
  const frame = document.getElementById('myframe');
  frame.addEventListener('load', (e) => {
    const buttons = frame.contentWindow.document.querySelectorAll('button');
    console.log('frame loaded', buttons );
    console.log([...buttons]);
  });
});