title: Detect load of iframe (not same domain, dynamically added) in javascript or jQuery?
body: <p>Is there a way to detect when an iframe is loaded in javascript / jQuery? With the following conditions:</p>
  
  <ul>
  <li>I can't control the iframe. It is added by another javascript plugin.</li>
  <li>It points to another domain (so I guess I can't use solutions of same domain).</li>
  <li>I can't know the moment the iframe is loaded. I just can make a time interval and check every time if there is an iframe and try to call to his load event (so the iframe is dynamically added to DOM)</li>
  </ul>
  
  <p>I've read about this in other questions but either they are incomplete or do not assume these three conditions. </p>
  
  <p>Thanks in advance.</p>
  
  <p><strong>ADDITION TO ANSWER OF</strong> @Jaromanda X:
  I needed to add to this answer an option in <code>observer.observe(document.body, { childList: true });</code> making actually this: <code>observer.observe(document.body, { childList: true, subtree: true });</code>. The <strong>subtree option</strong> works also for all descendants of the target (this case document.body).</p>