title: Detect Changes on Word (API Office)
body: <p>When you're editing a Word Document, it automatically detect after any update on the file. </p>
  
  <p>I don't find this feature in the Microsoft Documentation, Does it exist ? </p>
  
  <p>Beause, I would like to show a popup (to quit) only if there are modifications.</p>
  
  <p>Currently, i have to compare my two (base64 - string) documents, it seems to be not reliable, i prefere a event. </p>
  
  <p>Thanks </p>
  
  <p>More informations :
  My code is based with <a href="https://docs.microsoft.com/en-us/javascript/api/office/office.document?view=office-js#getfileasync-filetype--options--callback-" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/javascript/api/office/office.document?view=office-js#getfileasync-filetype--options--callback-</a> (getFile)</p>
  
  <pre><code>function _arrayBufferToBase64( buffer ) {
      var binary = '';
      var bytes = new Uint8Array( buffer );
      var len = bytes.byteLength;
      for (var i = 0; i &lt; len; i++) {
          binary += String.fromCharCode( bytes[ i ] );
      }
      return window.btoa( binary );
  }
  </code></pre>