Required device capabilitiesi - iphone

Question

If i use accelerometer in my app should i add Required device capabilitiesi in info.plist and enter accelerometer ?if yes what should i add exactly?

Answer 1

You should write code defensively and always "degrade" the app nicely.
For example, you should think of how you app will run if accelerometer is not present.
Have a look at the CMMotionManager class - in particular at its accelerometerActive property which returns a BOOL. Here is an example:
CMMotionManager *manager = [[CMMotionManager alloc] init];
if(!manager.accelerometerAvailable) {
NSLog(#"Accelerometer not available");
} else {
manager.accelerometerUpdateInterval = 1.0;
NSOperationQueue *motionQueue = [[NSOperationQueue alloc] init];
[manager startAccelerometerUpdatesToQueue: motionQueue withHandler:
^(CMAccelerometerData *data, NSError *error) {
NSLog(#"Accelerometer data: %#", [data description]);
}
];
}

Answer 2

You need to use
<key>UIRequiredDeviceCapabilities</key>
<array>
<string>accelerometer</string>
</array>
Further details in the iOS Application Programming Guide (page 89, table 5-1).
You do not need to include this key if your app detects only device orientation changes.

Answer 3

no you don't need to add anything to your info.plist.
Just make sure that your appDelegate implements protocol UIAccelerometerDelegate and then in your .m file just do:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
...
[[UIAccelerometer sharedAccelerometer] setDelegate:self];
....
}
- (void) accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration
{
//your accelerometer code
}