title: Capture Facebook share/post to FB event
body: <p>I am working on one of my pet projects. Where one of the features I need is as follows:</p>
  
  <ol>
  <li><p>User clicks the “share to Facebook” button on my web page, as done here <a href="https://developers.facebook.com/docs/plugins/share-button/" rel="nofollow">https://developers.facebook.com/docs/plugins/share-button/</a></p></li>
  <li><p>And then in Facebook popup window, user can either click “post/submit” or cancel or close the window. Is there any way to know that user did really post to his/her Facebook timeline?</p></li>
  <li><p>Please assume, that user is not my friend or have never liked my page, but user is currently logged in to Facebook in another browser tab.</p></li>
  <li><p>I see FB events, those can be captured in callback at <a href="https://developers.facebook.com/docs/reference/javascript/FB.Event.subscribe/" rel="nofollow">https://developers.facebook.com/docs/reference/javascript/FB.Event.subscribe/</a> , e.g. edge.create can capture like button. </p></li>
  </ol>
  
  <p>Similarly is there any way to capture “share/post to fb” ?</p>