title: JS equivalent for jQuery one()
body: <p>Can someone point me towards a solution for the following? I'm trying to find a JS equivalent for this jQuery code:</p>
  
  <pre><code>var formSelector = 'my selector here';
  var attribute = 'name';
  var formHistory = [];
  
  $(formSelector).one('focusout', function(e) {
      formHistory.push(e['target'].getAttribute(attribute));
  });
  </code></pre>