title: How to open my UINavigationController programmatically?
body: <p>One of the things I don't like about WYSIWYG/visual programming, is when you get to a point where you need to step outside of the box, you're left scratching your head. I'm at such a point right now along my iOS learning curve.</p>
  
  <p>I have a custom <code>UICollectionView</code> thing. In two places (create and edit points), I need to present a list to the user to enable/disable (select/deselect) items from a list. So I go to the storyboard and whip up something like this:</p>
  
  <p><img src="https://i.stack.imgur.com/1wLCU.png" alt="enter image description here"></p>
  
  <p>In the past, following tutorials, I would control-drag a link from some control to the NavigationController show in the middle, I would tell it was a modal segue, tune a couple of methods, and get an arrow connecting the two for my efforts.</p>
  
  <p>But in this case, I don't have obvious points to start that action from. I do have a + button. But it needs to do some other things first, and if all is well, then programmatically initiate the open, and somehow get notified of the state when it returns. Same for the individual cells, they might want to configure my table controller, and then open it, and be notified when it closes.</p>
  
  <p>So I'm looking for a recipe of how one does this, what the key methods I should be looking for are. Apple's docs are great for reference, but I find figuring out how to do something from scratch difficult.</p>