Permissions Handling

Description of required permissions, how to request and manage them.

Required Permissions

On SDK initialization, the host app passes a MoveConfig object to configure which of the SDK services should be activated. Some of those services require system permissions to be granted, or other features to be available.

From a usability perspective, Apple provides some guidelines about Requesting Permissions as part of their Human Interface Guidelines.

The table below shows each of the MoveConfig options and the corresponding required and optional permissions or sensors.

Service		Required permissions	Optional permissions
TimelineDetectionService
	Driving	Location Permission	Motion Permission Background Location Permission
	Bicycle	Location Permission Motion Permission	Background Location Permission
	Walking	Motion Permission	Background Location Permission
Driving Services
	Distraction-Free-Driving (DFD)	Gyroscope and Accelerometer availability
	Driving behavior events (DBE)	Gyroscope and Accelerometer availability
Other Services
	Points of Interest (POI)	Location Permission	Background Location Permission

If a required permission is missing during or after initialization, the SDK services will stop working and SDKMoveState will transit to.permissionMissingerror state.

Location Permission

Authorization

This section considers the iOS13 system location permissions changes.

Please check Location Permission Pre iOS13 for more information about handling the permission prior to iOS13

Starting iOS 13, system location is split into 2 layers: CLAuthorizationStatus and CLAccuracyAuthorization

CLAuthorizationStatus:

can be granted with one of the multiple access levels. Focusing only on the MOVE SDK relevant ones:

• CLAuthorizationStatus.authorizedAlways: The user authorized the app to start and access location services at any time. Can be requested by calling requestWhenInUseAuthorization().
• CLAuthorizationStatus.authorizedWhenInUse: The user authorized the app to start location services only while the app is in use. Can be requested by calling requestAlwaysAuthorization().

Starting iOS13, when an app requests.authorizedAlwaysthe system prevents apps from directly receiving the.authorizedAlwaysaccess level, but instead, the system breaks the access into 2 steps. First, it shows the user the permission prompt for.authorizedWhenInUseand later on, shows the.authorizedAlwayspermission prompt when the app (in our case the MOVE SDK embedded in your app) fetches the location in the background for the first time.

Check this WWDC19 session and apple documentation for further information about the iOS13 authorization status changes.

Automatic Detection

The MOVE SDK can automatically wake up the app and activate its services (like trip detection, etc..) fully in the background and without any user interaction, even if the app was killed by the user.

None of the SDK automatic detection services will work except if background location permissionauthorizationAlwaysis granted. Otherwise the services will only work when the host app is in the foreground.

CLAccuracyAuthorization:

Starting iOS13, Apple introduced 2 levels of accuracy access:

• .fullAccuracy: The user authorized the app to access location data with full accuracy.
• .reducedAccuracy: The user authorized the app to access location data with reduced accuracy.

The MOVE SDK requires full accuracy access to precisely detect trips and deliver high-quality service.

Plist

Apple requires apps requesting any system permission to provide reasoning for granting the permission. This reasoning is known as "purpose string" and is defined in the app's Info.plist file. Those purpose strings are displayed as an explanation of why the app needs those access types, in the alert shown by the system to ask the user for permission.

In the case of location permission, each access level requires including one or more corresponding keys with purpose strings.

Key	Required if
NSLocationWhenInUseUsageDescription	Your app requests When In Use authorization or Always authorization.
NSLocationAlwaysAndWhenInUseUsageDescription	Your app requests Always authorization.
NSLocationAlwaysUsageDescription	Your app supports iOS 10 and earlier and requests Always authorization.

Background Mode

Moreover, for background location access, Location updates Background Modes must be enabled:

1. Go to the Capabilities tab of your target settings

2. Turn on Background Modes and enable Location updates

Location updates background mode capability

For more details about how to request location permissions, check out this Apple document.

Sample Code

Requesting.authorizedAlwayslocation authorization looks something like this:

import CoreLocation
 
class Permission {
    let locationManager = CLLocationManager()
 
    func requestLocationPermission(){
        locationManager.delegate = self
        locationManager.requestAlwaysAuthorization()
    }  
}
 
extension Permission: CLLocationManagerDelegate {
    public func locationManager(_: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        // status
    }
}

Motion Permission

plist

Same as with Location permission, Motion permission requires including the NSMotionUsageDescription with its corresponding purpose string in the app's Info.plist file.

Permission

There is no direct way to request Motion Activities access permission like with Locations. Instead, the permission prompts the first time the Motions API is called.

Requesting the motion permission will look something like this:

import CoreMotion
 
func requestCoreMotionPermission(){
    let manager = CMMotionActivityManager()
    let now = NSDate()
 
    manager.queryActivityStartingFromDate(now, toDate: now, toQueue: NSOperationQueue.mainQueue(),
        withHandler: { (activities: [CMMotionActivity]?, error: NSError?) -> Void in
          if let error = error where error.code == Int(CMErrorMotionActivityNotAuthorized.rawValue){
            // "NotAuthorized"
         }else {
            // "Authorized"
         }
    })
}