title: On OS X, separating a GUI into multiple NIB files and NSView subclasses
body: <p>I am developing an OS X/Cocoa application and I want behavior like this:</p>
  
  <ul>
  <li>There is a sidebar with different options, let's say "Option A", "Option B", and "Option C".</li>
  <li>When you click A, B, or C, it loads a corresponding GUI into the main pane. Each GUI is a different NSView subclass, and it is defined in a different NIB/XIB file. For example, Option A might 3 buttons and be an instance of NSViewSubclassA while Option B might have 1 button and a text field and be an instance of NSViewSubclassB.</li>
  </ul>
  
  <p>How would I go about programming this?</p>