13. Alerting the User

At times, you need to grab your user’s attention. New data might arrive or status might change. You might want to tell your user that there’s going to be a wait before anything more happens—or that the wait is over and it’s time to come back and pay attention. iOS offers many ways to provide that heads-up to the user: from alerts and progress bars to audio pings. In this chapter, you discover how to build these indications into your applications and expand your user-alert vocabulary. You see real-life examples that showcase these classes and discover how to make sure your user pays attention at the right time.