What We’ve Learned

In this chapter, we’ve gone beyond the bounds of our original application and opened up our functionality to other apps on the user’s device. By defining a custom URL scheme and implementing openURL in the app delegate, we made it possible for other apps to open our app programmatically, and even pass in data for us to work with, like the screen name of a user for our app to fetch and display details about.

Thanks to iOS extensions, we now have the ability to go the other way: users can stay in another application but use functionality we provide through extension points like custom keyboards. We’ve also seen how frameworks let us share our code between app and extension, and how frameworks can also be used to share reusable code with other projects entirely.

Now that we’ve got a pretty complete application, our next task is going to be learning how to take a step back to figure out what to do when things go wrong.