title: How to check when a React Native component has finished RE-rendering?
body: <p>I am currently re-rendering Child components within a Parent component based on a state change and I need to know when the child component has completely mounted and re-rendered on screen. Here's a quasi-example:</p>
  
  <pre><code>&lt;Parent&gt;
    { this.state.showChild1 ? &lt;Child1/&gt; : &lt;Child2/&gt; }
  &lt;/Parent&gt;
  </code></pre>
  
  <p>The general procedure for responding after state change would be using <code>componentDidUpdate(prevProps, prevState)</code> however, this lifecycle event only fires after <code>state</code> has updated without considering the effects of what the state change would update within the <code>&lt;Parent&gt;</code> component. </p>
  
  <p>The problem I'm encountering then is that although state has completely updated, the new Child component is not yet available because it hasn't actually finished re-rendering yet. Is there a way to check when the Child components have re-rendered?  </p>