title: WKUserScript but wait for AJAX or element
body: <p>Using WKUserScript on iOS I’m querying some anchor tags of the DOM with JavaScript. Problem is even though the script is executed at the end of the document, the anchor tags are loaded via an AJAX call so not available when the script is run. </p>
  
  <p>How to wait for the AJAX to call its success handler before executing my JavaScript? </p>
  
  <p>Note: I have no access to the site page except through JavaScript. </p>