What We’ve Learned

In this chapter, we’ve brought together many of the things we learned in the book up to this point. The first three chapters were all about writing code, and the previous chapter was about building user interfaces with storyboards and Interface Builder. By using connections—actions that connect UI components to methods, and outlets that connect properties in the code back to the UI—we have completed the loop. We can now create our UIs visually, and back them up with code.

By applying what we’ve learned, we now have a minimal audio player user interface with a working Play/Pause button, and a title label that updates itself when the player URL is set.

We’ve got a bunch more to do before we can ship our podcast player, but first we should take a step back. Our player app works for now, but how can we be sure it’ll keep working, and that changes we make later won’t break it? In the next chapter, we’ll introduce Xcode’s support for unit testing, and let Xcode verify that our code really works like we think it does.