title: Angular 2 - How do you call a function in a sibling component?
body: <p>I have 2 sibling components that need to communicate:</p>
  
  <p><code>&lt;app-controls&gt;&lt;/app-controls&gt;
   &lt;app-main&gt;&lt;/app-main&gt;
  </code></p>
  
  <p>app-controls contains buttons that need to trigger events in the app-main component. Is there a Angular 2 style guide compliant way of doing so?</p>