title: Getting a list of active file viewers with apps script
body: <p>I've been googling for a while but have come up with no results that tell me I can't, but no results telling me I can.</p>
  
  <p>What I'm looking for is a way in apps script (or anything in their .NET/Java/Python...API) to give me a list of people who are actively looking at the sheet when I ask. I tried <a href="https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet#getViewers()" rel="nofollow">getViewers</a> but it gives me a list of all people with access, not the ones looking at it currently. If I wanted to do some data manipulation but didn't want to do it when people where in the file, or if I wanted to save the user emails of people who were in the file. It seems like it's part of analytics but I can't find anything that does what I want.</p>
  
  <p>We have a working version that does some on open magic/button script trigger but this requires the user to authorize and would like to improve the process and remove the authorization step.</p>
  
  <p>Anyone know a way to pull the list of people who are currently viewing a sheet/doc/slide?</p>