Installation • Usage • Customization • Known bugs • Issues • License

Inspired by (but unrelated to) Periscope’s permission control, PermissionScope is a Swift framework for intelligently requesting permissions from users. It contains not only a simple UI to request permissions but also a unified permissions API that can tell you the status of any given system permission or easily request them.

Some examples of multiple permissions requests, a single permission and the denied alert.

PermissionScope gives you space to explain your reasons for requesting permissions and allows users to tackle the system dialogs at their own pace. It presents a straightforward permissions design and is flexible enough to fit in to most UIKit-based apps.

Best of all, PermissionScope detects when your app’s permissions have been denied by a user and gives them an easy prompt to go into the system settings page to modify these permissions.

compatibility

PermissionScope requires iOS 8+, compatible with both Swift 3 and Objective-C based projects

For Swift 2.x support, please use the swift2 branch or the 1.0.2 release version. This branch was up-to-date on 9/6/16 but is not being maintained. All future efforts will go towards Swift 3 development.

installation

Installation for Carthage is simple enough:

github "nickoneill/PermissionScope" ~> 1.0

As for Cocoapods, use this to get the latest release:

use_frameworks!

pod 'PermissionScope'

And import PermissionScope in the files you’d like to use it.

dialog usage

The simplest implementation displays a list of permissions and is removed when all of them have satisfactory access.

class ViewController: UIViewController {
    let pscope = PermissionScope()

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set up permissions
        pscope.addPermission(ContactsPermission(),
            message: "We use this to steal\r\nyour friends")
        pscope.addPermission(NotificationsPermission(notificationCategories: nil),
            message: "We use this to send you\r\nspam and love notes")
        pscope.addPermission(LocationWhileInUsePermission(),
            message: "We use this to track\r\nwhere you live")

    // Show dialog with callbacks
        pscope.show({ finished, results in
            print("got results \(results)")
        }, cancelled: { (results) -> Void in
            print("thing was cancelled")
        })   
    }
}

The permissions view will automatically show if there are permissions to approve and will take no action if permissions are already granted. It will automatically hide when all permissions have been approved.

If you’re attempting to block access to a screen in your app without permissions (like, say, the broadcast screen in Periscope), you should watch for the cancel closure and take an appropriate action for your app.

customization

You can easily change the colors, label and buttons fonts with PermissionScope by modifying any of these properties:

In addition, the default behavior for tapping the background behind the dialog is to cancel the dialog (which calls the cancel closure you can provide on show). You can change this behavior with backgroundTapCancels during init.

If you’d like more control over the button text for a particular permission, you can use a .strings file for your intended language and override them that way. Please get in touch if you’d like to contribute a localization file for another language!

unified permissions API

PermissionScope also has an abstracted API for getting the state for a given permission and requesting permissions if you need to do so outside of the normal dialog UI. Think of it as a unified iOS permissions API that can provide some features that even Apple does not (such as detecting denied notification permissions).

switch PermissionScope().statusContacts() {
case .Unknown:
    // ask
    PermissionScope().requestContacts()
case .Unauthorized, .Disabled:
    // bummer
    return
case .Authorized:
    // thanks!
    return
}

calling request* methods directly

Normally PermissionScope is used to walk users through necessary permissions before they’re allowed to do something in your app. Sometimes you may wish to instead call into the various request* permissions-seeking methods of PermissionScope directly, from your own UI.

To call these methods directly, you must first set the viewControllerForAlerts method to your current UIViewController, in case PermissionScope needs to present some alerts to the user for denied or disabled permissions:

let pscope = PermissionScope()
pscope.viewControllerForAlerts = self

You will probably also want to set the onAuthChange, onCancel, and onDisabledOrDenied closures, which are called at the appropriate times when the request* methods are finished, otherwise you won’t know when the work has been completed.

pscope.onAuthChange = { (finished, results) in
    println("Request was finished with results \(results)")
    if results[0].status == .Authorized {
        println("They've authorized the use of notifications")
        UIApplication.sharedApplication().registerForRemoteNotifications()
    }
}
pscope.onCancel = { results in
    println("Request was cancelled with results \(results)")
}
pscope.onDisabledOrDenied = { results in
    println("Request was denied or disabled with results \(results)")
}

And then you might call it when the user toggles a switch:

@IBAction func notificationsChanged(sender: UISwitch) {
    if sender.on {
        // turn on notifications
        if PermissionScope().statusNotifications() == .Authorized {
            UIApplication.sharedApplication().registerForRemoteNotifications()
        } else {
            pscope.requestNotifications()
        }
    } else {
        // turn off notifications
    }

If you’re also using PermissionScope in the traditional manner, don’t forget to set viewControllerForAlerts back to it’s default, the instance of PermissionScope. The easiest way to do this is to set it explicitly before you call a request* method, and then reset it in your closures.

pscope.viewControllerForAlerts = pscope as UIViewController

PermissionScope registers user notification settings, not remote notifications

Users will get the prompt to enable notifications when using PermissionScope but it’s up to you to watch for results in your app delegate’s didRegisterUserNotificationSettings and then register for remote notifications independently. This won’t alert the user again. You’re still responsible for handling the shipment of user notification settings off to your push server.

extra requirements for permissions

location

You must set these Info.plist keys for location to work

Trickiest part of implementing location permissions? You must implement the proper key in your Info.plist file with a short description of how your app uses location info (shown in the system permissions dialog). Without this, trying to get location permissions will just silently fail. Software!

Use NSLocationAlwaysUsageDescription or NSLocationWhenInUseUsageDescription where appropriate for your app usage. You can specify which of these location permissions you wish to request with .LocationAlways or .LocationInUse while configuring PermissionScope.

bluetooth

The NSBluetoothPeripheralUsageDescription key in the Info.plist specifying a short description of why your app needs to act as a bluetooth peripheral in the background is optional.

However, enabling background-modes in the capabilities section and checking the acts as a bluetooth LE accessory checkbox is required.

healthkit

Enable HealthKit in your target’s capabilities, required.

known bugs

• ITC app rejection with the following reason: “This app attempts to access privacy-sensitive data without a usage description”. (#194)

Solution: TBD

• When the user is taken to the Settings.app, if any of the app’s permissions are changed (whilst the app was in the background), the app will crash. (#160)

Solution: None. Works as intended by the OS.

• Link “Show me” does not work on denied a permission (#61)

Solution: Run your app without the debugger.

• When using Carthage, the following error occurs: Module file was created by an older version of the compiler.

Solution: Use the --no-use-binaries flag (e.g: carthage update --no-use-binaries).

license

PermissionScope uses the MIT license. Please file an issue if you have any questions or if you’d like to share how you’re using this tool.