title: React: how to update props of root component
body: <p>I have a React root component mounted on the dom, which receives JSON from the initial page load as props. </p>
  
  <p>After an API call, I want to update that JSON. </p>
  
  <p>I don't know what is the best pattern here, since searching for <code>Update props on root component</code> gives me very few results and the #1 page is actually for the Preact lib (not React). </p>
  
  <p>Should I 'clone' the JSON into my root component's  state in the <code>constructor</code>, which allows me to change it after the API call via <code>this.setState</code> on the root component itself? </p>
  
  <p>The other option I'm aware is calling ReactDOM.render again, but that seems more complex: even tough I could pass all it's current props and the new one as <code>{...this.props, propsThatWasUpdated }</code>, I assume the call to <code>ReactDOM.render()</code> will reset the component's inner state, which I don't want. </p>