title: viewWillAppear in React Native
body: <p>I'm trying to stream video from the camera in a View with React Native. The problem is, if the user presses the home button, temporarily leave the app and switch back, the stream URL will be changed.</p>
  
  <p>So I need to update the URL in a function similar to <code>viewWillAppear</code> as in native iOS framework. Any suggestion on this?</p>