title: Dynamically add regions to Marionette layout
body: <p>I have a layout, but cannot define all of its regions in advance because they are not known.</p>
  
  <p>So later on an ItemView is created and I'd like to create a new region in the layout using the view's ID as the region's name so I can then say:</p>
  
  <pre><code>layout.dynamicRegionName.show(newItemView);
  </code></pre>
  
  <p>But there is cyclic dependency here. </p>
  
  <ol>
  <li><p>I haven't rendered the view yet, so I cannot make a reference to its DOM element to be used in the layout's call to .addRegion()</p></li>
  <li><p>I cannot render it, precisely because I want it to get attached to the DOM tree through the dynamically added region by calling its .show()</p></li>
  </ol>
  
  <p>@DerickBailey In the Marionette.Layout docs in github I believe there is an error in the example that has: <code>layout.show(new MenuView());</code></p>
  
  <p>but technically this is close to what we'd need here i.e. to be able to do:</p>
  
  <pre><code>layout.addRegion(VAR_WITH_NEW_REGION_NAME, aViewInstance);
  </code></pre>
  
  <p>and have this add a new Region into the layout rendering inside it directly the view instance.</p>
  
  <p>Am I missing some other obvious way to achieve this? Is that a known missing functionality? Is there a reason not to have it?</p>
  
  <p>I'm aware of this previous Q: "<a href="https://stackoverflow.com/questions/12868494/dynamically-add-remove-regions-to-a-layout">Dynamically add/remove regions to a layout</a>"
  but don't see any clear/definite answer to it.</p>