All of the code is in place, and you have a better understanding of multithreading and how callbacks can be used in a multithreaded environment. Yet, if you build and run your app and add a new movie, the rating won't be displayed yet.
The following are the three reasons why this is happening:
- The table view cell that shows the movie isn't updated yet.
- The network request doesn't succeed because of App Transport Security.
- Updates to movie objects aren't observed yet.
Let's solve these issues in order, starting with the table view cell.