title: Passing Data with Subjects and Proxies
body: <p>Is it possible to have a 2 way data flow using Subjects in a service? Suppose for example that I want some component to retrieve information and then post it through the service Subject for other another component to consume.</p>
  
  <p>The consuming component then makes some changes to this information and then re-posts it so that the original component can retrieve changes.</p>
  
  <p>Is this possible using the Observer pattern? </p>
  
  <p>Also, if I wanted to watch this data for changes (let's say that the data came in through an array), would I have to use a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy" rel="nofollow noreferrer">proxy</a> to accomplish this?</p>