The iOS 5 Developer’s Cookbook: Core Concepts and Essential Recipes for iOS Programmers, Third Edition

14. Device Capabilities

Each iPhone device represents a meld of unique, shared, momentary, and persistent properties. These properties include the device’s current physical orientation, its model name, its battery state, and its access to onboard hardware. This chapter looks at the device from its build configuration to its active onboard sensors. It provides recipes that return a variety of information items about the unit in use. You read about testing for hardware prerequisites at runtime and specifying those prerequisites in the application’s Info.plist file. You discover how to solicit sensor feedback and subscribe to notifications to create callbacks when those sensor states change. This chapter covers the hardware, file system, and sensors ...