title: Check if element is visible in DOM
body: <p>Is there any way that I can check if an element is visible in pure JS (no jQuery) ?</p>
  <p>So, given a DOM element, how can I check if it is visible or not? I tried:</p>
  <pre><code>window.getComputedStyle(my_element)['display']);
  </code></pre>
  <p>but it doesn't seem to be working.  I wonder which attributes should I check. It comes to my mind:</p>
  <pre><code>display !== 'none'
  visibility !== 'hidden'
  </code></pre>
  <p>Any others that I might be missing?</p>