title: React redux favorites action
body: <p>I am new to react-redux world and having some trouble visualising a piece of complex data flow (I think).</p>
  
  <p>Assume the state contains a collection of tracks and an array of favorite track ids. User could favorite a track from a number of various components e.g. musicplayer, tracklist, charts and all the others would have to rerender.</p>
  
  <p>At the moment, I'm triggering an action to add/remove the track id to/from the favorites array. But I can't quite see how to proceed from there.</p>
  
  <p>My plan is to trigger another action for e.g. the trackItem reducer to listen and carry on. Or could each related component directly subscribe to changes of the favorites collection? Or can I have two reducers listening to the same action? I have now idea how to implement something like that and also I have a gut feeling that I'm on the wrong path.</p>
  
  <p>Feels like I'm struggling to get rid of my backbone-marionette habits. How would you do it?</p>
  
  <p>My other plan is to have an isFavorited boolean within the track item json and use an action/reduces to update/toggle that property. I understand that <a href="https://github.com/gaearon/normalizr" rel="nofollow">normalizr</a> will merge instances with the same id, so any component subscribed to its changes will react.</p>