title: clientWidth function in React
body: <p>I am experienced in working with Javascript, but am pretty new to working with React. When coding purely in javascript that would be rendered in browser, I would often use:</p>
  <pre><code>width = document.getElementById('element_id').clientWidth
  </code></pre>
  <p>to dynamically size my svg elements to different container sizes. Does something like this exist in React? I have been trying to use the same technique, but as expected, it does not work because the the template is rendered after the script is run.</p>