title: Updating a UITableViewController not visible on the Screen
body: <p>Here is my scenario. I have a product screen and a product details screen. Basically you can click on the product and go to the product details screen. Now, while I am on the product details screen I want to do some action like change the product name and I want that to reflect in the product screen when I go <em>back</em> using the back button. </p>
  
  <p>How can I do that? </p>
  
  <p><strong>Solutions I tried:</strong> </p>
  
  <p>I created a protocol on the product details controller and had product controller subscribe to that protocol. Every time I change the product name the protocol got triggered in the product controller but I was unable to change any UI elements on the product controller since the product controller was not currently visible. </p>
  
  <p>Currently, I am reloading all the data on <strong>viewWillAppear</strong> which works but it means it makes a call to the server (iCloud) each time the view is loaded. This is causing long wait times. </p>
  
  <p>Any recommendations?</p>