title: re-mount React child components
body: <p>Here I've initialized my application:</p>
  
  <pre><code>ReactDOM.render(
      &lt;App /&gt;,
      document.getElementById('app')
  );
  </code></pre>
  
  <p>Now I need for all components in tree to call componentDidMount again because I want for all these components in tree to call api requests again.</p>
  
  <p>I've done it like this:</p>
  
  <pre><code>const appKey = 0;
  
  ReactDOM.render(
      &lt;App key={appKey} /&gt;,
      document.getElementById('app')
  );
  </code></pre>
  
  <p>And each time I need for components to call componentDidMount again I add 1 to appKey and call ReactDOM.render again. It works. But maybe there is another way of doing this without using key attribute?</p>