title: React Visible + Add class
body: <p>It's works:</p>
  
  <pre class="lang-js prettyprint-override"><code>var onChange = function (isVisible) {
      console.log('Element is now %s', isVisible ? 'visible' : 'hidden');
      if(isVisible = 'visible'){
          //here I need add class
      }
  };
  </code></pre>
  
  <p>And the VisibilitySensor is in inside component <strong>Needs</strong> in div className =<strong>Need</strong>.</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;VisibilitySensor onChange={onChange}/&gt;
  </code></pre>
  
  <p>The code is working well, I can see console.log after rendering.
  So. what is my problem.</p>
  
  <p>I wan't add class <strong>animated fadeInUp</strong>. <strong>if isVisible = 'visible'</strong></p>
  
  <p>How can I add this class to <strong>Needs</strong> className React?</p>
  
  <p>If it help, here is all code:</p>
  
  <p><a href="https://pastebin.com/bnTKbXC4" rel="nofollow noreferrer">https://pastebin.com/bnTKbXC4</a></p>