title: Open and close a set of workbooks one by one by an HTML/JS add-in
body: <p>I am wondering if it is possible to let an HTML/JS add-in open and close a set of workbooks one by one.</p>
  
  <p>I have not seen the JavaScript API to open or close a workbook, and don't know if it is doable in a JavaScript function.</p>
  
  <p>Otherwise, because VBA can repeat opening and closing workbooks, is it possible to set a mechanism in VBA to run systematically a function of an HTML/JS add-in every time a workbook is open?</p>